Leucine
17 benefits mapped to clinical evidence across supplements.
Dose per serving from products
3,243 products in our catalogue print how much Leucine a serving holds.
Most common: 1 g to 2.5 g, 37% of 3,243 products.
| Dose per serving | Products |
|---|---|
| 50 mg or less | 118 |
| 50 mg to 100 mg | 58 |
| 100 mg to 250 mg | 111 |
| 250 mg to 500 mg | 216 |
| 500 mg to 1 g | 289 |
| 1 g to 2.5 g | 1,193 |
| 2.5 g to 5 g | 1,132 |
| over 5 g | 126 |
Dose per serving from research
106 study groups in 65 studies say how much Leucine participants took a day.
These are the doses the studies gave. They are not a recommendation.
Most common: 1 g to 2.5 g, 31% of 106 study groups.
| Daily dose | Study groups |
|---|---|
| 10 mg or less | 1 |
| 10 mg to 25 mg | 8 |
| 25 mg to 50 mg | 8 |
| 50 mg to 100 mg | 3 |
| 100 mg to 250 mg | 0 |
| 250 mg to 500 mg | 1 |
| 500 mg to 1 g | 0 |
| 1 g to 2.5 g | 33 |
| 2.5 g to 5 g | 24 |
| 5 g to 10 g | 23 |
| over 10 g | 5 |
Commonly used together
81 of 135 study groups took Leucine with something else. Shown: what 3 or more different studies gave.
What was given together, not what works together.
| Taken with | Study groups |
|---|---|
| Branched-Chain Amino Acids | 17 |
| Whey Protein | 15 |
| Isoleucine | 13 |
| Vitamin D | 11 |
| Valine | 8 |
| Essential Amino Acids | 7 |
| Casein | 5 |
| Protein | 5 |
| Calcium | 3 |
Benefit Evidence
Anabolism + recovery
Less catabolism, shorter stay
BCAA/leucine support healing
Anabolism + recovery
Less catabolism, shorter stay
BCAA/leucine support healing
Research sources
Muscle growth (45)
- Nutritional supplementation of the leucine metabolite beta-hydroxy-beta-methylbutyrate (hmb) during resistance training
PubMed ID: 10978853
HMB (leucine metabolite) during training increased FF mass trend and upper-body strengthâsupports leucine pathway for growth/preservation.
- No Difference between Spray Dried Milk and Native Whey Supplementation with Strength Training
PubMed ID: 30157103
Native whey produced higher acute blood leucine and, combined with resistance training, increased muscle mass (but no extra long-term benefit vs milk).
- Effects of exercise and amino acid supplementation on body composition and physical function in community-dwelling elderly Japanese sarcopenic women: a randomized controlled trial
PubMed ID: 22142410
Leucine-rich essential amino-acid supplement + exercise increased leg muscle mass in sarcopenic elderly (clinical growth outcome).
- Whey protein supplementation preserves postprandial myofibrillar protein synthesis during short-term energy restriction in overweight and obese adults
PubMed ID: 25644344
Whey (rich in leucine) preserved meal-stimulated MPS during energy restriction, reflecting improved utilization of dietary protein.
- Whey protein, amino acids, and vitamin D supplementation with physical activity increases fat-free mass and strength, functionality, and quality of life and decreases inflammation in sarcopenic elderly
PubMed ID: 26864356
Whey+EAA (including 4 g leucine) with vitamin D and exercise increased lean mass in sarcopenic elderly (large RCT).
- Impact of β-hydroxy-β-methylbutyrate (HMB) on muscle loss and protein metabolism in critically ill patients: A RCT
PubMed ID: 34358832
HMB reduced net protein breakdown in ventilated patients, supporting a net anabolic effect (HMB is a bioactive leucine metabolite) though primary muscle loss endpoint was unchanged.
- Dose-Dependent Increases in Whole-Body Net Protein Balance and Dietary Protein-Derived Amino Acid Incorporation into Myofibrillar Protein During Recovery from Resistance Exercise in Older Men
PubMed ID: 30722014
Direct doseâresponse in older men: higher milk protein (higher leucine exposure) increased whole-body net protein balance and myofibrillar FSRâstrong mechanistic support for muscle anabolism.
- Dose-response effects of dietary protein on muscle protein synthesis during recovery from endurance exercise in young men: a double-blind randomized trial
PubMed ID: 32359142
Clear human evidence that an optimal postâexercise protein dose maximizes myofibrillar protein synthesis and wholeâbody net balance â directly about protein/leucine utilization.
- Nutrient ingestion, protein intake, and sex, but not age, affect the albumin synthesis rate in humans
PubMed ID: 17585023
Feeding increased hepatic albumin fractional synthesis measured with labeled leucine and the fed response scaled with protein intake â supports how leucine/AA intake improves specific protein synthesis rates (indirect).
- Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial
PubMed ID: 26817506
Higherâprotein diet (higher leucine intake) during intense exercise/energy deficit promoted greater lean mass gain versus lower protein diet.
- Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study
PubMed ID: 10850936
HMB-containing (leucine metabolite) supplement significantly increased lean body mass and weight in wasting HIV patients (clinical RCT).
- β-Hydroxy-β-methylbutyrate, Arginine, and Glutamine Complex on Muscle Volume Loss in Critically Ill Patients: A Randomized Control Trial
PubMed ID: 31134640
HMB-containing supplement reduced femoral muscle loss in a less-severe ICU subgroup, consistent with anabolic/anticatabolic effects.
- Effect of administration of β-hydroxy-β-methyl butyrate-enriched formula after liver transplantation: A pilot randomized controlled trial
PubMed ID: 32593895
HMBâenriched formula (a leucine metabolite) increased SMI at 2 months after liver transplantâclinically meaningful muscle mass gains (indirect to leucine).
- Effects of Astragalus membranaceus and Panax notoginseng Saponins Extract on the Pharmacokinetics of Whey Protein Absorption, Intestinal Permeability, and Muscle Function: A Pilot Study
PubMed ID: 41683325
Astragalus/Panax saponin increased BCAA (including leucine) AUC and modestly improved grip strength, indicating enhanced absorption/utilization of BCAAs.
- Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training
PubMed ID: 8941534
HMB (leucine metabolite) reduced muscle proteolysis and increased fatâfree mass and strength during resistance trainingâdirect evidence of promoting muscle accretion.
- Age and aerobic exercise training effects on whole body and muscle protein metabolism
PubMed ID: 14506079
Ageârelated declines in protein turnover documented and exercise increased mixed muscle protein synthesisâpractical information on improving protein use across ages.
- Effect of minimal enteral feeding on splanchnic uptake of leucine in the postabsorptive state in preterm infants
PubMed ID: 12538787
Minimal enteral feeding increased splanchnic leucine uptake in preterm infants indicating increased local protein synthesis (improved aminoâacid utilization).
- Effects of early amino acid administration on leucine and glucose kinetics in premature infants
PubMed ID: 16627891
Early IV AA in preterm infants increased incorporation of leucine into body protein and raised leucine oxidation â shows increased protein incorporation.
- The influence of 8 weeks of whey-protein and leucine supplementation on physical and cognitive performance
PubMed ID: 20975109
Whey plus leucine for 8 weeks increased lean massâdirect evidence of anabolic/lean-mass gain.
- Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men
PubMed ID: 21367943
Higher peak plasma leucine (whey) correlated with greater postprandial muscle FSR in older menâsupports leucine's role in stimulating protein synthesis.
- [Interventions for frailty and sarcopenia in community-dwelling elderly women]
PubMed ID: 23883636
In older women, leucineârich amino acids with exercise improved leg muscle mass and strength versus control.
- Leucine supplementation of a low-protein mixed macronutrient beverage enhances myofibrillar protein synthesis in young men: a double-blind, randomized trial
PubMed ID: 24284442
Lowâprotein beverage + ~5 g leucine raised blood leucine and boosted MPS similar to a large protein doseâsupports leucine's anabolic role.
- Four-month course of soluble milk proteins interacts with exercise to improve muscle strength and delay fatigue in elderly participants
PubMed ID: 25444576
4âmonth intervention with leucineârich milk protein + exercise increased appendicular muscle massâpractical hypertrophy evidence.
- Effects of a vitamin D and leucine-enriched whey protein nutritional supplement on measures of sarcopenia in older adults, the PROVIDE study: a randomized, double-blind, placebo-controlled trial
PubMed ID: 26170041
Vitamin D + leucineâenriched whey twice daily modestly increased appendicular muscle mass in older adults (large RCT).
- Impact of the Macronutrient Composition of a Nutritional Supplement on Muscle Protein Synthesis Rates in Older Men: A Randomized, Double Blind, Controlled Trial
PubMed ID: 26308291
Leucineâenriched whey (21 g) strongly increased muscle protein synthesis in older menâa direct anabolic effect.
- Fast-digestive protein supplement for ten days overcomes muscle anabolic resistance in healthy elderly men
PubMed ID: 26008820
Fastâdigesting milk protein (higher leucine availability) increased myosin and mitochondrial protein synthesis in elderly menâsupports anabolic responses.
- Ingestion of Wheat Protein Increases In Vivo Muscle Protein Synthesis Rates in Healthy Older Men in a Randomized Trial
PubMed ID: 27440260
Whey (higher leucine) increased myofibrillar protein synthesis in older men versus other protein sourcesâsupports better protein utilization with leucine-rich proteins.
- Effectiveness of essential amino acid supplementation in stimulating whole body net protein anabolism is comparable between COPD patients and healthy older adults
PubMed ID: 28285641
EAA mixtures enriched with extra leucine increased whole-body net protein gain in older and COPD patientsâdirect evidence of improved protein accretion with leucine-enriched EAAs.
- Enhanced nutrient supply to very low birth weight infants is associated with higher blood amino acid concentrations and improved growth
PubMed ID: 29132733
Enhanced amino-acid nutrition (higher BCAAs including leucine) in very low birth weight infants yielded faster growthâsupports anabolic effects in growth contexts.
- Sufficient levels of 25-hydroxyvitamin D and protein intake required to increase muscle mass in sarcopenic older adults - The PROVIDE study
PubMed ID: 28132725
Leucine-enriched whey + vitamin D increased appendicular muscle mass in sarcopenic older adults (direct evidence of muscle gain).
- Effects of Postexercise Protein Intake on Muscle Mass and Strength During Resistance Training: Is There an Optimal Ratio Between Fast and Slow Proteins?
PubMed ID: 28422532
Fast protein increased leucine bioavailability after exercise (acute improvement in amino-acid availability), though long-term adaptation was similar.
- Postexercise Dietary Protein Ingestion Increases Whole-Body Leucine Balance in a Dose-Dependent Manner in Healthy Children
PubMed ID: 28381530
Dose-dependent whole-body leucine balance after post-exercise protein indicates efficient use of ingested amino acids for net anabolism.
- Effects of a leucine-enriched amino acid supplement on muscle mass, muscle strength, and physical function in post-stroke patients with sarcopenia: A randomized controlled trial
PubMed ID: 30273819
Leucineâenriched amino acid supplement increased skeletal muscle mass index in post-stroke sarcopenic patients.
- Branched-chain amino acid and branched-chain ketoacid ingestion increases muscle protein synthesis rates in vivo in older adults: a double-blind, randomized trial
PubMed ID: 31250889
6 g BCAA/BCKA rapidly doubled early myofibrillar protein synthesis in older men (shortâlived effect)âsupports anabolic potential of branchedâchain amino acids.
- No Significant Differences in Muscle Growth and Strength Development When Consuming Soy and Whey Protein Supplements Matched for Leucine Following a 12 Week Resistance Training Program in Men and Women: A Randomized Trial
PubMed ID: 32486007
Leucineâmatched soy and whey produced similar increases in lean mass during 12 weeks RTâindicates leucine sufficiency drives growth.
- Leucine-Enriched Protein Supplementation Increases Lean Body Mass in Healthy Korean Adults Aged 50 Years and Older: A Randomized, Double-Blind, Placebo-Controlled Trial
PubMed ID: 32570811
Modest but significant increases in lean body mass in older adults given leucineâenriched protein over 12 weeks.
- Effect of an Enriched Protein Drink on Muscle Mass and Glycemic Control during Combined Lifestyle Intervention in Older Adults with Obesity and Type 2 Diabetes: A Double-Blind RCT
PubMed ID: 33379181
Leucineâenriched whey with diet/exercise increased total and appendicular lean mass in older adults with obesity/T2D.
- Effectiveness of a Novel Food Composed of Leucine, Omega-3 Fatty Acids and Probiotic Lactobacillus paracasei PS23 for the Treatment of Sarcopenia in Elderly Subjects: A 2-Month Randomized Double-Blind Placebo-Controlled Trial
PubMed ID: 36364828
Multinutrient (incl. leucine) RCT improved handgrip and performance in sarcopenic older adultsâsupports anabolic/muscle preservation effects.
- De-Training Effects Following Leucine-Enriched Whey Protein Supplementation and Resistance Training in Older Adults with Sarcopenia: A Randomized Controlled Trial with 24 Weeks of Follow-Up
PubMed ID: 36437767
RCT in older sarcopenic adults: leucineâenriched whey + resistance training produced larger increases in ASMI and strength than training alone.
- Dileucine ingestion, but not leucine, increases lower body strength and performance following resistance training: A double-blind, randomized, placebo-controlled trial
PubMed ID: 39739679
Dileucine produced larger gains in lowerâbody strength and work capacity, consistent with hypertrophic/strength adaptations.
- Myofibrillar and Mitochondrial Protein Synthesis Rates Do Not Differ in Young Men Following the Ingestion of Carbohydrate with Milk Protein, Whey, or Micellar Casein after Concurrent Resistance- and Endurance-Type Exercise
PubMed ID: 30698725
Protein+CHO after exercise increased myofibrillar synthesis vs CHO alone (milk/whey/casein aggregated effect).
- Collagen Protein Ingestion during Recovery from Exercise Does Not Increase Muscle Connective Protein Synthesis Rates
PubMed ID: 37202878
Whey increased myofibrillar synthesis postexercise vs placeboâdirect muscle growth mechanism.
- Biological responses during high-dose protein nutrition in the critically ill: a randomized controlled trial
PubMed ID: 40617772
Parenteral highâdose amino acids increased wholeâbody protein balance measured using 13Câleucineâdirect tracer evidence of improved protein utilization with higher amino acid/leucine delivery.
- Muscle-Related Effect of Whey Protein and Vitamin D(3) Supplementation Provided before or after Bedtime in Males Undergoing Resistance Training
PubMed ID: 35684089
Whey protein (leucineârich) + vitamin D over 6 weeks increased lean mass in young adultsâsupports muscle accrual where leucine likely contributed.
- Improving rehabilitation in sarcopenia: a randomized-controlled trial utilizing a muscle-targeted food for special medical purposes
PubMed ID: 32961041
Leucineâenriched whey + vitamin D produced large gains in appendicular lean mass and handgrip strength in sarcopenic older inpatientsâstrong evidence for muscle anabolism.
Body composition (43)
- Improving rehabilitation in sarcopenia: a randomized-controlled trial utilizing a muscle-targeted food for special medical purposes
PubMed ID: 32961041
RCT showed clear preservation/increase of appendicular lean mass with leucineâenriched whey in older sarcopenic patients.
- Biological responses during high-dose protein nutrition in the critically ill: a randomized controlled trial
PubMed ID: 40617772
In critically ill patients, higher aminoâacid dosing increased wholeâbody protein balance measured using 13Câleucineâdirectly relevant to preserving lean mass during illness.
- Parenteral administration of different amounts of branch-chain amino acids in septic patients: clinical and metabolic aspects
PubMed ID: 9118656
High-BCAA PN in septic patients increased protein markers and associated with improved outcomesâsupports preservation of protein stores in severe illness.
- Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study
PubMed ID: 10850936
HMB/Arg/Gln supplement produced a substantial increase in lean body mass versus placebo in wasting HIV patientsâstrong evidence for lean-mass preservation/ gain.
- β-Hydroxy-β-methylbutyrate, Arginine, and Glutamine Complex on Muscle Volume Loss in Critically Ill Patients: A Randomized Control Trial
PubMed ID: 31134640
HMB/Arg/Gln complex reduced femoral muscle loss in a less-severe ICU subgroup â direct evidence of lean-mass preservation in illness.
- Functional and metabolic effects of omega-3 polyunsaturated fatty acid supplementation and the role of β-hydroxy-β-methylbutyrate addition in chronic obstructive pulmonary disease: A randomized clinical trial
PubMed ID: 39181037
Adding HMB to EPA/DHA in COPD patients altered protein turnover and was associated with fat loss and modest lean-tissue changes, suggesting preservation effects.
- Prospective study on the efficacy of branched-chain amino acids in septic patients
PubMed ID: 1907675
High-BCAA parenteral solutions in septic patients improved nitrogen balance and reduced proteolysis markers, supporting lean-mass preservation.
- Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training
PubMed ID: 8941534
HMB reduced proteolysis and increased fatâfree mass in resistanceâtrained subjectsâclear evidence for lean mass preservation/gain.
- Metabolic effects of keto acid--amino acid supplementation in patients with chronic renal insufficiency receiving a low-protein diet and recombinant human erythropoietin--a randomized controlled trial
PubMed ID: 11603100
KA/AA supplementation increased plasma leucine and albumin and slowed renal decline; supports lean-mass maintenance in CKD.
- Effects of low-protein diet supplemented with ketoacids and erythropoietin in chronic renal failure: a long-term metabolic study
PubMed ID: 11803607
KA+EPO+LPD in CKD improved albumin and body mass measures over 3 years â preservation of nutritional status/lean mass.
- Effects of early amino acid administration on leucine and glucose kinetics in premature infants
PubMed ID: 16627891
Early IV amino acids in very preterm infants increased incorporation of leucine into body protein â supports accrual/preservation of lean tissue.
- The influence of 8 weeks of whey-protein and leucine supplementation on physical and cognitive performance
PubMed ID: 20975109
Whey+leucine increased lean body mass over 8 weeksâdirect preservation/gain of lean mass.
- Whey protein supplementation during resistance training augments lean body mass
PubMed ID: 24015719
~9âmonth resistance training with daily whey (highâleucine) produced greater lean mass gains than soy/carbohydrateâsupports lean mass accrual/preservation with training.
- A high whey protein-, leucine-, and vitamin D-enriched supplement preserves muscle mass during intentional weight loss in obese older adults: a double-blind randomized controlled trial
PubMed ID: 25646324
Leucineâenriched whey+D supplement preserved appendicular muscle mass during a 13âweek hypocaloric diet + resistance trainingâdirect evidence.
- Four-month course of soluble milk proteins interacts with exercise to improve muscle strength and delay fatigue in elderly participants
PubMed ID: 25444576
Leucineârich milk protein + exercise increased fatâfree and appendicular muscle mass in older menâsupports preservation/augmentation of lean mass.
- Effects of a vitamin D and leucine-enriched whey protein nutritional supplement on measures of sarcopenia in older adults, the PROVIDE study: a randomized, double-blind, placebo-controlled trial
PubMed ID: 26170041
Vitamin D + leucineâenriched whey increased appendicular muscle mass in sarcopenic older adults (RCT).
- Effectiveness of essential amino acid supplementation in stimulating whole body net protein anabolism is comparable between COPD patients and healthy older adults
PubMed ID: 28285641
EAA mixtures with extra leucine increased whole-body net protein gain in older adults and COPD patientsâsupportive for lean mass preservation in catabolic or older populations.
- Sufficient levels of 25-hydroxyvitamin D and protein intake required to increase muscle mass in sarcopenic older adults - The PROVIDE study
PubMed ID: 28132725
Leucineâenriched whey increased appendicular muscle mass in sarcopenic older adults (preservation/restoration of lean mass).
- Postexercise Dietary Protein Ingestion Increases Whole-Body Leucine Balance in a Dose-Dependent Manner in Healthy Children
PubMed ID: 28381530
Dose-dependent positive whole-body leucine balance after exercise indicates anabolic environment favoring lean-mass preservation.
- Effects of a leucine-enriched amino acid supplement on muscle mass, muscle strength, and physical function in post-stroke patients with sarcopenia: A randomized controlled trial
PubMed ID: 30273819
Leucine-enriched supplement increased SMI in post-stroke sarcopenic patients (preservation/recovery of lean tissue).
- Muscle-targeted nutritional support for rehabilitation in patients with parkinsonian syndrome
PubMed ID: 31278117
Whey/leucine/vitamin D during rehab preserved skeletal muscle mass and improved function in parkinsonism (multiâingredient).
- Effects of Leucine Administration in Sarcopenia: A Randomized and Placebo-controlled Clinical Trial
PubMed ID: 32230954
Daily leucine in nursingâhome residents helped preserve muscle massâsupports maintenance under adverse/limited intake conditions.
- Leucine-Enriched Protein Supplementation Increases Lean Body Mass in Healthy Korean Adults Aged 50 Years and Older: A Randomized, Double-Blind, Placebo-Controlled Trial
PubMed ID: 32570811
Randomized trial in adults âĽ50 showed modest, statistically significant lean mass increases with leucineâenriched protein.
- Effect of an Enriched Protein Drink on Muscle Mass and Glycemic Control during Combined Lifestyle Intervention in Older Adults with Obesity and Type 2 Diabetes: A Double-Blind RCT
PubMed ID: 33379181
During hypocaloric diet plus exercise, leucineâenriched whey preserved/increased lean massâdirect evidence of muscle maintenance during dieting.
- Efficacy of L-Leucine Supplementation Coupled with a Calorie-Restricted Diet to Promote Weight Loss in Mid-Life Women
PubMed ID: 33030983
In a 12âweek caloric restriction trial, a higher proportion of leucine subjects retained/added lean mass (trend), suggesting possible benefit for muscle preservation during dieting.
- SarcojointÂŽ, the branched-chain amino acid-based supplement, plus resistance exercise improved muscle mass in adults aged 50Â years and older: A double-blinded randomized controlled trial
PubMed ID: 34838980
BCAAâcontaining formula plus exercise increased midâthigh CSA in a subgroup and reduced body fatâsupports lean tissue preservation in part.
- Effectiveness of a Novel Food Composed of Leucine, Omega-3 Fatty Acids and Probiotic Lactobacillus paracasei PS23 for the Treatment of Sarcopenia in Elderly Subjects: A 2-Month Randomized Double-Blind Placebo-Controlled Trial
PubMed ID: 36364828
Leucineâcontaining supplement prevented appendicular lean mass loss and improved functional measures in sarcopenic older adults.
- De-Training Effects Following Leucine-Enriched Whey Protein Supplementation and Resistance Training in Older Adults with Sarcopenia: A Randomized Controlled Trial with 24 Weeks of Follow-Up
PubMed ID: 36437767
RT + leucineâenriched whey improved muscle mass and helped preserve those gains during 24âweek detraining.
- The impact of leucine supplementation on body composition and glucose tolerance following energy restriction: an 8-week RCT in adults at risk of the metabolic syndrome
PubMed ID: 37923932
Randomized trial during energy restriction: 3 g/day leucine attenuated loss of fatâfree/lean tissue mass vs placebo (strongest direct evidence for dieting).
- A Randomized Controlled Trial on the Effects of Leucine-Supplement Combined with Nutritional Counseling on Body Composition in Mix Cancer Older Men
PubMed ID: 38257103
Older men with GI cancer taking leucine capsules tended to gain weight and appendicular skeletal muscle mass vs baseline.
- Anti-sarcopenic effect of leucine-enriched branched-chain amino acid supplementation among elderly chronic kidney disease patients: a double-blinded randomized controlled trial
PubMed ID: 40381110
Elderly CKD patients on leucineâenriched BCAA gained ~0.4 kg lean mass vs placebo (statistically significant).
- Small-Scale Randomized Controlled Trial to Explore the Impact of β-Hydroxy-β-Methylbutyrate Plus Vitamin D(3) on Skeletal Muscle Health in Middle Aged Women
PubMed ID: 36364934
HMB+vit D reduced IMAT and maintained/increased lean mass in sedentary middle-aged women.
- Collagen Protein Ingestion during Recovery from Exercise Does Not Increase Muscle Connective Protein Synthesis Rates
PubMed ID: 37202878
Whey increased myofibrillar synthesis after exerciseâmechanistic support for lean-mass preservation.
- Nutritional supplementation of the leucine metabolite beta-hydroxy-beta-methylbutyrate (hmb) during resistance training
PubMed ID: 10978853
HMB (leucine metabolite) tended to increase fat-free mass during resistance training vs placebo.
- No Difference between Spray Dried Milk and Native Whey Supplementation with Strength Training
PubMed ID: 30157103
Training with supplemental (higher-leucine) native whey increased muscle mass, though no advantage vs milk.
- Effects of exercise and amino acid supplementation on body composition and physical function in community-dwelling elderly Japanese sarcopenic women: a randomized controlled trial
PubMed ID: 22142410
Sarcopenic elderly: leucine-rich AAS + exercise increased leg muscle mass and improved odds of mass/strength gain.
- Whey protein supplementation preserves postprandial myofibrillar protein synthesis during short-term energy restriction in overweight and obese adults
PubMed ID: 25644344
Whey (high-leucine) strongly attenuated the decline in postprandial myofibrillar protein synthesis during energy restrictionâdirect, high-quality evidence.
- Whey protein, amino acids, and vitamin D supplementation with physical activity increases fat-free mass and strength, functionality, and quality of life and decreases inflammation in sarcopenic elderly
PubMed ID: 26864356
Whey+EAA+vitamin D with exercise produced a +1.7 kg fat-free mass gain vs placebo in sarcopenic elderly.
- Impact of β-hydroxy-β-methylbutyrate (HMB) on muscle loss and protein metabolism in critically ill patients: A RCT
PubMed ID: 34358832
HMB reduced net protein breakdown and improved bodyâcomposition proxy (phase angle) in ICU patients â direct evidence for leanâmass preservation (HMB = leucine metabolite).
- Dose-Dependent Increases in Whole-Body Net Protein Balance and Dietary Protein-Derived Amino Acid Incorporation into Myofibrillar Protein During Recovery from Resistance Exercise in Older Men
PubMed ID: 30722014
Higher protein/leucine exposure improved whole-body net protein balance and myofibrillar FSR in older menâsupports lean mass maintenance.
- Dose-response effects of dietary protein on muscle protein synthesis during recovery from endurance exercise in young men: a double-blind randomized trial
PubMed ID: 32359142
Optimizing postâexercise protein (and leucine content) maximizes MyoPS and improves wholeâbody net balance, supporting lean mass maintenance.
- Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial
PubMed ID: 26817506
Higherâprotein diet (2.4 g/kg/d) during large energy deficit preserved lean mass while promoting fat lossâdirect evidence for muscle maintenance during dieting.
- Effect of Protein Supplementation During Diet-Induced Weight Loss on Muscle Mass and Strength: A Randomized Controlled Study
PubMed ID: 29687650
Whey (leucineârich) protein during weight loss slightly reduced early muscle loss, indicating benefit for muscle preservation while dieting.
Healthy aging (25)
- Effects of adequate dietary protein with whey protein, leucine, and vitamin D supplementation on sarcopenia in older adults: An open-label, parallel-group study
PubMed ID: 32928579
Improved gait speed in sarcopenic elders with whey+leucine+vitamin D, a functional aging outcome.
- Circulating amino acids and the risk of macrovascular, microvascular and mortality outcomes in individuals with type 2 diabetes: results from the ADVANCE trial
PubMed ID: 29728717
Large cohort: higher circulating leucine associated with lower mortality in T2D, suggesting a link to longevity/healthspan (observational).
- Age and aerobic exercise training effects on whole body and muscle protein metabolism
PubMed ID: 14506079
Large tracer study shows ageârelated declines in protein turnover and that exercise boosts muscle protein synthesis across agesârelevant to strategies to preserve muscle with aging.
- Whey protein stimulates postprandial muscle protein accretion more effectively than do casein and casein hydrolysate in older men
PubMed ID: 21367943
Whey (higher leucine & faster kinetics) produced larger postprandial MPS in older men, supporting anabolic responses relevant to healthy aging.
- [Interventions for frailty and sarcopenia in community-dwelling elderly women]
PubMed ID: 23883636
Leucineârich aminoâacid supplementation combined with exercise improved appendicular muscle mass/function in older womenârelevant to healthy aging.
- A high whey protein-, leucine-, and vitamin D-enriched supplement preserves muscle mass during intentional weight loss in obese older adults: a double-blind randomized controlled trial
PubMed ID: 25646324
RCT in older obese adults: leucineâenriched whey+D preserved appendicular muscle mass during weight lossârelevant to healthy aging/sarcopenia prevention.
- Four-month course of soluble milk proteins interacts with exercise to improve muscle strength and delay fatigue in elderly participants
PubMed ID: 25444576
4âmonth trial in older men: leucineârich milk protein + exercise increased muscle mass, strength and enduranceâsupports functional aging.
- Ingestion of Wheat Protein Increases In Vivo Muscle Protein Synthesis Rates in Healthy Older Men in a Randomized Trial
PubMed ID: 27440260
Whey (higher leucine availability) increased myofibrillar protein synthesis in older men versus other proteins, supporting a role for leucine-rich proteins in healthy aging muscle maintenance.
- Medium-Chain Triglycerides in Combination with Leucine and Vitamin D Benefit Cognition in Frail Elderly Adults: A Randomized Controlled Trial
PubMed ID: 28552878
Randomized trial in frail elderly showed cognitive and functional improvements with a supplement containing leucine+MCT+vitamin D; effect likely multifactorial but leucine may have contributed to anabolic/neural benefits.
- Sufficient levels of 25-hydroxyvitamin D and protein intake required to increase muscle mass in sarcopenic older adults - The PROVIDE study
PubMed ID: 28132725
Leucine-enriched whey improved muscle mass and lower-limb function in sarcopenic older adults (direct clinical evidence).
- Effects of a leucine-enriched amino acid supplement on muscle mass, muscle strength, and physical function in post-stroke patients with sarcopenia: A randomized controlled trial
PubMed ID: 30273819
Leucine-enriched supplement increased muscle mass, strength and motor function in post-stroke sarcopenic patients (rehab context relevant to aging/decline).
- Effects of Leucine Administration in Sarcopenia: A Randomized and Placebo-controlled Clinical Trial
PubMed ID: 32230954
6 g/day leucine in nursingâhome older adults helped preserve muscle mass and walking/respiratory function vs placebo.
- Leucine-Enriched Protein Supplementation Increases Lean Body Mass in Healthy Korean Adults Aged 50 Years and Older: A Randomized, Double-Blind, Placebo-Controlled Trial
PubMed ID: 32570811
Older adults had modest but significant lean mass increases after 12 weeks of leucineâenriched protein.
- Effect of an Enriched Protein Drink on Muscle Mass and Glycemic Control during Combined Lifestyle Intervention in Older Adults with Obesity and Type 2 Diabetes: A Double-Blind RCT
PubMed ID: 33379181
Leucineâenriched whey preserved/increased appendicular and total lean mass in older adults during weight loss/exercise.
- Leucine-enriched whey protein supplementation, resistance-based exercise, and cardiometabolic health in older adults: a randomized controlled trial
PubMed ID: 34520104
Leucineâenriched whey improved cardiometabolic markers (LDL, fasting insulin) in older adults, pertinent to healthy aging.
- Effectiveness of a Novel Food Composed of Leucine, Omega-3 Fatty Acids and Probiotic Lactobacillus paracasei PS23 for the Treatment of Sarcopenia in Elderly Subjects: A 2-Month Randomized Double-Blind Placebo-Controlled Trial
PubMed ID: 36364828
RCT in sarcopenic older adults: leucine-containing multi-nutrient improved physical performance and strength, consistent with healthyâaging effects.
- Association of leucine and other branched chain amino acids with clinical outcomes in malnourished inpatients: a secondary analysis of the randomized clinical trial EFFORT
PubMed ID: 39245679
Low serum leucine strongly associated with higher 180âday mortality in malnourished inpatients, linking leucine status to survival/aging outcomes.
- Collagen Protein Ingestion during Recovery from Exercise Does Not Increase Muscle Connective Protein Synthesis Rates
PubMed ID: 37202878
Whey (leucine-rich) raised myofibrillar synthesis after exercise in older adults.
- Effects of exercise and amino acid supplementation on body composition and physical function in community-dwelling elderly Japanese sarcopenic women: a randomized controlled trial
PubMed ID: 22142410
Large RCT in sarcopenic elderly: leucine-rich AAS + exercise improved muscle mass/strength (direct aging-relevant benefit).
- Whey protein supplementation preserves postprandial myofibrillar protein synthesis during short-term energy restriction in overweight and obese adults
PubMed ID: 25644344
Whey (high-leucine) preserved postprandial MPS during short-term energy restrictionâhelps maintain muscle with aging-related catabolism.
- Whey protein, amino acids, and vitamin D supplementation with physical activity increases fat-free mass and strength, functionality, and quality of life and decreases inflammation in sarcopenic elderly
PubMed ID: 26864356
Large RCT in sarcopenic elderly showing whey+EAA (including 4 g leucine) + vitamin D+exercise increased lean mass and strength, directly relevant to healthy aging.
- Impact of β-hydroxy-β-methylbutyrate (HMB) on muscle loss and protein metabolism in critically ill patients: A RCT
PubMed ID: 34358832
HMB (a leucine metabolite) reduced net protein breakdown and improved phase angle in ICU patients â suggests preservation of muscle/quality relevant to healthy aging (indirect evidence).
- Dose-Dependent Increases in Whole-Body Net Protein Balance and Dietary Protein-Derived Amino Acid Incorporation into Myofibrillar Protein During Recovery from Resistance Exercise in Older Men
PubMed ID: 30722014
Doseâresponse in older men: higher protein/leucine increased myofibrillar FSR and net protein balanceâsupports improved anabolic responsiveness in aging.
- Dose-response effects of dietary protein on muscle protein synthesis during recovery from endurance exercise in young men: a double-blind randomized trial
PubMed ID: 32359142
Human postâexercise protein doseâresponse showing protein (and thus leucine) maximizes myofibrillar protein synthesis â relevant to preserving muscle with aging.
- Improving rehabilitation in sarcopenia: a randomized-controlled trial utilizing a muscle-targeted food for special medical purposes
PubMed ID: 32961041
Large RCT in sarcopenic older inpatients: leucine-enriched whey + vitamin D improved gait speed, appendicular lean mass, SPPB and reduced length of stayâdirect evidence for functional aging benefits.
Illness recovery (24)
- Prospective study on the efficacy of branched-chain amino acids in septic patients
PubMed ID: 1907675
High-BCAA parenteral nutrition in septic patients improved nitrogen balance and reduced proteolysis markers, supporting clinical recovery.
- Functional and metabolic effects of omega-3 polyunsaturated fatty acid supplementation and the role of β-hydroxy-β-methylbutyrate addition in chronic obstructive pulmonary disease: A randomized clinical trial
PubMed ID: 39181037
HMB+EPA/DHA altered protein turnover and body composition in COPD patients, indicating benefits during recovery from chronic illness.
- Effect of administration of β-hydroxy-β-methyl butyrate-enriched formula after liver transplantation: A pilot randomized controlled trial
PubMed ID: 32593895
HMBâenriched formula after liver transplant increased SMI, grip strength and shortened hospital LOSâstrong clinical signal for improved recovery (HMB = leucine metabolite).
- Whey protein, amino acids, and vitamin D supplementation with physical activity increases fat-free mass and strength, functionality, and quality of life and decreases inflammation in sarcopenic elderly
PubMed ID: 26864356
Whey+EAA+vitamin D plus exercise improved lean mass, strength and reduced inflammation in sarcopenic elderlyâsupports recovery capacity.
- Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study
PubMed ID: 10850936
HMB-containing supplement increased lean mass and improved some immune markers in wasting HIV patientsâsupports recovery from catabolic illness.
- Parenteral administration of different amounts of branch-chain amino acids in septic patients: clinical and metabolic aspects
PubMed ID: 9118656
High-BCAA parenteral nutrition in septic ICU patients increased protein markers and was associated with lower ICU mortalityâstrongest clinical evidence among provided studies for recovery after severe illness.
- [Impact of intravenous nutrition on plasma free amino acid spectrum and immune function for patients with sepsis]
PubMed ID: 17571315
IV amino-acid nutrition in sepsis improved AA profiles and some immune proteinsâsupports recovery capacity in critical illness.
- β-Hydroxy-β-methylbutyrate, Arginine, and Glutamine Complex on Muscle Volume Loss in Critically Ill Patients: A Randomized Control Trial
PubMed ID: 31134640
In critically ill patients, HMB/Arg/Gln reduced muscle loss in less-severe subgroup â supports recovery of muscle/functional status after illness.
- Impact of β-hydroxy-β-methylbutyrate (HMB) on muscle loss and protein metabolism in critically ill patients: A RCT
PubMed ID: 34358832
HMB reduced net protein breakdown and improved phase angle and selfâreported global health in ventilated ICU patients â strong clinical signal that a leucine metabolite aids recovery in critical illness.
- Improving rehabilitation in sarcopenia: a randomized-controlled trial utilizing a muscle-targeted food for special medical purposes
PubMed ID: 32961041
Leucineâenriched supplementation in hospitalized sarcopenic older adults reduced length of stay and improved function, indicating improved recovery from illness/immobility.
- Oral Nutritional Supplementation in Cancer Patients Who Were Receiving Chemo/Chemoradiation Therapy: A Multicenter, Randomized Phase II Study
PubMed ID: 32363940
ONS containing whey/leucine in oncology patients was safe, increased protein intake, and is practical for supporting nutritional recovery during chemo.
- Biological responses during high-dose protein nutrition in the critically ill: a randomized controlled trial
PubMed ID: 40617772
Highâdose parenteral amino acids increased wholeâbody protein balance in critically ill patients using 13Câleucine tracerâstrong support that aminoâacid/leucine delivery assists recovery in catabolic illness.
- [Obesity and progression of chronic renal insufficiency: a Czech long term prospective double-blind randomised multicentre study]
PubMed ID: 16871760
Keto-amino-acid therapy in obese CKD patients led to clinical improvements over 3 years with changes in amino-acid parameters.
- A randomized clinical trial investigating the efficacy of targeted nutrition as adjunct to exercise training in COPD
PubMed ID: 28608438
Leucine-enriched multi-nutrient supplement improved inspiratory muscle strength and activity levels during pulmonary rehab in COPD.
- Treatment of symptomatic oral mucositis with sodium hyaluronate and synthetic amino acid precursors of collagen in patients undergoing haematopoietic stem cell transplantation
PubMed ID: 29921408
Spray containing hyaluronic acid + amino acids including leucine reduced mucositis severity and duration after stem-cell transplant.
- Disease-Modifying, Neuroprotective Effect of N-Acetyl-l-Leucine in Adult and Pediatric Patients With Niemann-Pick Disease Type C
PubMed ID: 40513057
Longâterm NâacetylâLâleucine administration in NiemannâPick C slowed/reversed expected neurologic decline vs historical progressionâsubstantial diseaseâspecific recovery signal.
- Amino Acid Profile in Malnourished Patients with Liver Cirrhosis and Its Modification with Oral Nutritional Supplements: Implications on Minimal Hepatic Encephalopathy
PubMed ID: 34836020
HMB (a leucine metabolite) improved aminoâacid profiles and was associated with fewer MHE events in malnourished cirrhoticsâclinical recovery signal.
- Clinical outcome and cost-effectiveness of a 1-year nutritional intervention programme in COPD patients with low muscle mass: The randomized controlled NUTRAIN trial
PubMed ID: 30954363
Leucineâenriched supplement in muscleâwasted COPD improved activity and maintained weight/QoL over 12 monthsâsupports recovery in chronic illness.
- Effects of a leucine-enriched amino acid supplement on muscle mass, muscle strength, and physical function in post-stroke patients with sarcopenia: A randomized controlled trial
PubMed ID: 30273819
Leucine-enriched amino acid supplementation in post-stroke sarcopenic patients improved muscle mass, strength and motor function during rehabilitation (direct evidence for recovery after illness).
- Sufficient levels of 25-hydroxyvitamin D and protein intake required to increase muscle mass in sarcopenic older adults - The PROVIDE study
PubMed ID: 28132725
In sarcopenic older adults leucine-enriched whey improved muscle mass and function, supporting recovery/resilience in a frail population.
- Enhanced nutrient supply to very low birth weight infants is associated with higher blood amino acid concentrations and improved growth
PubMed ID: 29132733
Enhanced amino-acid nutrition in very low birth weight infants increased growth velocityâshows that increased amino-acid (including leucine) provision aids recovery/growth in vulnerable clinical populations.
- Effectiveness of essential amino acid supplementation in stimulating whole body net protein anabolism is comparable between COPD patients and healthy older adults
PubMed ID: 28285641
EAA mixtures with extra leucine increased whole-body net protein gain in older adults and COPD patientsâimproved protein accretion is relevant to recovery from illness or chronic catabolic states.
- Rapid EPA and DHA incorporation and reduced PGE2 levels after one week intervention with a medical food in cancer patients receiving radiotherapy, a randomized trial
PubMed ID: 23123043
Short course of leucineârich medical food in cancer patients lowered PGE2 and changed leukocyte fattyâacid composition, markers relevant to recovery/inflammation.
- Effects of early amino acid administration on leucine and glucose kinetics in premature infants
PubMed ID: 16627891
Early IV AA in very preterm infants increased leucine incorporation into protein and oxidation â supports metabolic recovery and growth in ill/newborn patients.
Metabolism (15)
- Postprandial Glucose and Gastrointestinal Hormone Responses of Healthy Subjects to Wheat Biscuits Enriched with L-Arginine or Branched-Chain Amino Acids of Plant Origin
PubMed ID: 36297065
BCAA (high-leucine) biscuits lowered postprandial glucose and insulin iAUC in humans â direct metabolic benefit.
- Alterations in 3-Hydroxyisobutyrate and FGF21 Metabolism Are Associated With Protein Ingestion-Induced Insulin Resistance
PubMed ID: 28473464
Study showed whole protein (but not equivalent leucine) reduced insulin-stimulated glucose disposal, indicating leucine alone may not drive protein-related insulin effects.
- Effect of an Enriched Protein Drink on Muscle Mass and Glycemic Control during Combined Lifestyle Intervention in Older Adults with Obesity and Type 2 Diabetes: A Double-Blind RCT
PubMed ID: 33379181
Improved fasting insulin and insulin sensitivity during hypocaloric diet/exercise with leucineâenriched whey.
- Modulation of Energy Sensing by Leucine Synergy with Natural Sirtuin Activators: Effects on Health Span
PubMed ID: 32758058
Leucine + resveratrol lowered insulin resistance ~33% in prediabetic adults; effect is combinationâdependent but metabolic.
- Leucine-enriched whey protein supplementation, resistance-based exercise, and cardiometabolic health in older adults: a randomized controlled trial
PubMed ID: 34520104
Leucineâenriched whey reduced LDL, fasting insulin and improved HOMAâIR in older adultsâdirect metabolic benefits.
- Leucine and Sildenafil Combination Therapy Reduces Body Weight and Metformin Enhances the Effect at Low Dose: A Randomized Controlled Trial
PubMed ID: 33369909
Combination trials (leucine + other drugs) produced small weight and lipid/CRP improvementsâsupports metabolic effects (confounded).
- Insulin resistance mediate the association between leucine intake, dietary glycemic index, and type 2 diabetes in secondary cardiovascular prevention: path analysis from Brazilian cardioprotective nutritional (BALANCE) program
PubMed ID: 40156624
Higher dietary leucine linked with lower TyG index (insulinâresistance) and indirect lower diabetes risk in a large observational sample.
- A novel nutritional supplement containing amino acids and chromium decreases postprandial glucose response in a randomized, double-blind, placebo-controlled study
PubMed ID: 32579549
Leucine-containing AA+chromium drink reduced postprandial glucose excursions (24% iAUC reduction) in overweight adults.
- [Obesity and progression of chronic renal insufficiency: a Czech long term prospective double-blind randomised multicentre study]
PubMed ID: 16871760
Keto-amino-acid therapy improved BMI/proteinuria and slowed renal decline with associated leucine-related parameter changesâclinical metabolic benefits.
- Dose-response effects of dietary protein on muscle protein synthesis during recovery from endurance exercise in young men: a double-blind randomized trial
PubMed ID: 32359142
Shows protein doseâdependent improvement in wholeâbody net balance and MyoPS after exercise â relevant to metabolic regulation.
- Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial
PubMed ID: 26817506
Highâprotein diet (increasing leucine intake) during large energy deficit increased lean mass and fat loss versus lower protein, indicating metabolic advantages of higher protein/leucine intake.
- Weight-loss diets and 2-y changes in circulating amino acids in 2 randomized intervention trials
PubMed ID: 26791187
Large weightâloss RCTs: dietâinduced weight loss lowered circulating leucine and improvements in insulin resistance correlated with AA changesâlinks leucine metabolism to metabolic health.
- Randomised clinical trial: a leucine-metformin-sildenafil combination (NS-0200) vs placebo in patients with non-alcoholic fatty liver disease
PubMed ID: 29696666
NSâ0200 (leucine + metformin + sildenafil) reduced liver fat and improved glycemia in a highâALT subgroupâcombination trial implicating leucine as a component.
- Safety, Tolerability, and Biologic Activity of AXA1125 and AXA1957 in Subjects With Nonalcoholic Fatty Liver Disease
PubMed ID: 34382947
AXA1125 (multiâaminoâacid including leucine) reduced liver fat and improved HOMAâIRâmetabolic benefit though multiâingredient.
- Is diabetes mellitus-linked amino acid signature associated with β-blocker-induced impaired fasting glucose?
PubMed ID: 24627569
Higher baseline blood leucine associated with increased risk of atenolol-induced impaired fasting glucose â direct metabolic association.
Strength (20)
- Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training
PubMed ID: 8941534
HMB increased strength during resistance training and reduced markers of muscle damageâdirect strength benefit.
- Effects of Astragalus membranaceus and Panax notoginseng Saponins Extract on the Pharmacokinetics of Whey Protein Absorption, Intestinal Permeability, and Muscle Function: A Pilot Study
PubMed ID: 41683325
Astragalus/Panax saponin increased BCAA absorption and produced a modest (+5.2%) improvement in grip strength in humans.
- Effectiveness of a Novel Food Composed of Leucine, Omega-3 Fatty Acids and Probiotic Lactobacillus paracasei PS23 for the Treatment of Sarcopenia in Elderly Subjects: A 2-Month Randomized Double-Blind Placebo-Controlled Trial
PubMed ID: 36364828
Leucineâcontaining supplement improved handgrip strength ~4 kg vs placebo in sarcopenic older adults.
- Whey protein, amino acids, and vitamin D supplementation with physical activity increases fat-free mass and strength, functionality, and quality of life and decreases inflammation in sarcopenic elderly
PubMed ID: 26864356
Whey+EAA+vitamin D with exercise increased handgrip strength in sarcopenic elderly (clinically meaningful).
- Effects of exercise and amino acid supplementation on body composition and physical function in community-dwelling elderly Japanese sarcopenic women: a randomized controlled trial
PubMed ID: 22142410
Exercise + leucine-rich AAS produced a significant 9.3% increase in knee-extension strength in sarcopenic women.
- Effects of a leucine-enriched amino acid supplement on muscle mass, muscle strength, and physical function in post-stroke patients with sarcopenia: A randomized controlled trial
PubMed ID: 30273819
RCT showed increased handgrip strength and improved motor function with leucine-enriched supplement in post-stroke sarcopenic patients.
- Nutritional supplementation of the leucine metabolite beta-hydroxy-beta-methylbutyrate (hmb) during resistance training
PubMed ID: 10978853
HMB supplementation during training increased upper-body strength vs placebo (leucine metabolite evidence).
- Improving rehabilitation in sarcopenia: a randomized-controlled trial utilizing a muscle-targeted food for special medical purposes
PubMed ID: 32961041
Handgrip strength increased substantially (+~5.45 kg treatment difference) with leucineâenriched whey + vitamin D in sarcopenic older inpatients.
- Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial
PubMed ID: 26817506
Highâprotein diet during energy deficit increased lean mass; strength gains are plausible and some functional benefits were observed (moderate evidence).
- Sufficient levels of 25-hydroxyvitamin D and protein intake required to increase muscle mass in sarcopenic older adults - The PROVIDE study
PubMed ID: 28132725
Sarcopenic older adults receiving leucine-enriched whey improved lower-limb function, implying strength-related gains.
- Medium-Chain Triglycerides in Combination with Leucine and Vitamin D Increase Muscle Strength and Function in Frail Elderly Adults in a Randomized Controlled Trial
PubMed ID: 27075909
Leucine + MCT + vitamin D in frail elderly improved grip strength and walking speed; coâsupplements confound attribution.
- Dileucine ingestion, but not leucine, increases lower body strength and performance following resistance training: A double-blind, randomized, placebo-controlled trial
PubMed ID: 39739679
Dileucine produced large, significant increases in legâpress 1RM vs placebo/leucineâdirect strength benefit.
- Effect of a leucine-rich supplement in combination with nutrition and physical exercise in advanced cancer patients: A randomized controlled intervention trial
PubMed ID: 32340904
Multimodal program with leucineârich supplement improved handgrip strength in advanced cancer patients.
- The Effects of Timing of a Leucine-Enriched Amino Acid Supplement on Body Composition and Physical Function in Stroke Patients: A Randomized Controlled Trial
PubMed ID: 32610608
Breakfast timing of leucineârich supplement yielded larger leg press strength gains in stroke rehab patients.
- De-Training Effects Following Leucine-Enriched Whey Protein Supplementation and Resistance Training in Older Adults with Sarcopenia: A Randomized Controlled Trial with 24 Weeks of Follow-Up
PubMed ID: 36437767
Leucineâenriched whey combined with RT produced greater handgrip and strength gains and maintained them during detraining.
- Effects of free leucine supplementation and resistance training on muscle strength and functional status in older adults: a randomized controlled trial
PubMed ID: 25926725
Free leucine (10 g/d) with resistance training produced moderate gains in maximal isometric leg strength in older adults (RCT, but high attrition).
- Four-month course of soluble milk proteins interacts with exercise to improve muscle strength and delay fatigue in elderly participants
PubMed ID: 25444576
Training + leucineârich supplement increased strength measures and endurance in older menâstrength benefit documented.
- [Interventions for frailty and sarcopenia in community-dwelling elderly women]
PubMed ID: 23883636
Combined exercise + leucineârich amino acids improved muscle strength in older women (improvement stronger with combined intervention).
- The influence of 8 weeks of whey-protein and leucine supplementation on physical and cognitive performance
PubMed ID: 20975109
Significant increase in bench-press performance after 8 weeks whey+leucine.
- Effects of leucine and whey protein supplementation during eight weeks of unilateral resistance training
PubMed ID: 16686554
Randomized one-leg resistance training study: leucine+whey produced greater strength gains than placebo despite similar CSA increases.
Blood sugar (11)
- A novel nutritional supplement containing amino acids and chromium decreases postprandial glucose response in a randomized, double-blind, placebo-controlled study
PubMed ID: 32579549
Randomized crossover: leucine-containing AA+chromium drink reduced 0â120min glucose iAUC by 24% vs placebo.
- Postprandial metabolic response of breast-fed infants and infants fed lactose-free vs regular infant formula: A randomized controlled trial
PubMed ID: 28623320
Formulaâfed infants showed larger postprandial BCAA (including leucine) rises accompanied by higher insulin â indicates leucine/BCAA can stimulate insulin and influence glycemia (infant data).
- Metabolic responses of healthy or prediabetic adults to bovine whey protein and sodium caseinate do not differ
PubMed ID: 25733461
Whey/sodium caseinate co-ingested with carbohydrate markedly increased insulin and reduced peak glucose in prediabetics.
- Hydrolyzed casein decreases postprandial glucose concentrations in T2DM patients irrespective of leucine content
PubMed ID: 22432727
Adding leucine to a hydrolyzed casein product markedly increased insulin secretion, demonstrating an insulinotropic effect though glucose lowering was driven by the protein product.
- Alterations in 3-Hydroxyisobutyrate and FGF21 Metabolism Are Associated With Protein Ingestion-Induced Insulin Resistance
PubMed ID: 28473464
Study showed whole protein (but not matched leucine) decreased insulin-stimulated glucose disposalâindicates leucine alone does not reproduce whole-protein effects on insulin sensitivity.
- Effect of an Enriched Protein Drink on Muscle Mass and Glycemic Control during Combined Lifestyle Intervention in Older Adults with Obesity and Type 2 Diabetes: A Double-Blind RCT
PubMed ID: 33379181
Improved fasting insulin and insulin sensitivity indices in older adults with obesity/T2D during intervention.
- Modulation of Energy Sensing by Leucine Synergy with Natural Sirtuin Activators: Effects on Health Span
PubMed ID: 32758058
Leucine combined with resveratrol reduced insulin resistance substantially in prediabetics, though effect cannot be attributed to leucine alone.
- Leucine-enriched whey protein supplementation, resistance-based exercise, and cardiometabolic health in older adults: a randomized controlled trial
PubMed ID: 34520104
Leucineâenriched whey reduced fasting insulin and improved HOMAâIR in older adultsâevidence for improved glycemic/metabolic control.
- Safety, Tolerability, and Biologic Activity of AXA1125 and AXA1957 in Subjects With Nonalcoholic Fatty Liver Disease
PubMed ID: 34382947
AXA1125 improved HOMAâIR and reduced liver fat (metabolic improvements) in a 16âweek trial; leucine is a component of the formulation.
- Is diabetes mellitus-linked amino acid signature associated with β-blocker-induced impaired fasting glucose?
PubMed ID: 24627569
Higher baseline plasma leucine independently associated with much greater odds of developing atenololâinduced impaired fasting glucose â direct human association with glycemic risk.
- Postprandial Glucose and Gastrointestinal Hormone Responses of Healthy Subjects to Wheat Biscuits Enriched with L-Arginine or Branched-Chain Amino Acids of Plant Origin
PubMed ID: 36297065
BCAA-enriched (high-leucine) biscuits lowered postprandial glucose and insulin iAUC in healthy adults â strong direct evidence.
Exercise recovery (12)
- Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training
PubMed ID: 8941534
HMB reduced markers of muscle damage (CPK) and proteolysis after exercise, indicating faster recovery.
- Effects of early amino acid administration on leucine and glucose kinetics in premature infants
PubMed ID: 16627891
Early IV AA in preterm infants increased leucine incorporation into protein â supports faster tissue building/repair in a vulnerable population.
- Postexercise Dietary Protein Ingestion Increases Whole-Body Leucine Balance in a Dose-Dependent Manner in Healthy Children
PubMed ID: 28381530
Post-exercise protein/leucine produced dose-dependent increases in net whole-body leucine balance and reduced catabolic stateâsupports recovery.
- Effects of a leucine-enriched amino acid supplement on muscle mass, muscle strength, and physical function in post-stroke patients with sarcopenia: A randomized controlled trial
PubMed ID: 30273819
Leucine-enriched supplementation during rehabilitation improved functional recovery and muscle mass/strength post-stroke.
- Collagen Protein Ingestion during Recovery from Exercise Does Not Increase Muscle Connective Protein Synthesis Rates
PubMed ID: 37202878
Whey enhanced contractile MPS postexercise relative to placebo.
- Nutritional supplementation of the leucine metabolite beta-hydroxy-beta-methylbutyrate (hmb) during resistance training
PubMed ID: 10978853
HMB tended to suppress CPK and improved strength recovery during trainingâevidence of reduced damage/accelerated recovery.
- Impact of β-hydroxy-β-methylbutyrate (HMB) on muscle loss and protein metabolism in critically ill patients: A RCT
PubMed ID: 34358832
HMB reduced net protein breakdown in critically ill patients and improved subjective global health â supportive of improved recovery kinetics (clinical context).
- Dose-Dependent Increases in Whole-Body Net Protein Balance and Dietary Protein-Derived Amino Acid Incorporation into Myofibrillar Protein During Recovery from Resistance Exercise in Older Men
PubMed ID: 30722014
Higher postâexercise protein/leucine doses increased myofibrillar FSR, mechanistic support for improved recovery.
- Dose-response effects of dietary protein on muscle protein synthesis during recovery from endurance exercise in young men: a double-blind randomized trial
PubMed ID: 32359142
Defines protein dose to maximize MyoPS after exercise â supports synthesis and repair processes key to recovery.
- Parenteral administration of different amounts of branch-chain amino acids in septic patients: clinical and metabolic aspects
PubMed ID: 9118656
BCAA-enriched PN in septic ICU patients raised anabolic markers and lowered ICU mortalityâsupports post-illness recovery including muscle repair.
- Nutritional treatment for acquired immunodeficiency virus-associated wasting using beta-hydroxy beta-methylbutyrate, glutamine, and arginine: a randomized, double-blind, placebo-controlled study
PubMed ID: 10850936
HMB-containing supplement improved lean mass in HIV-wastingâsupports recovery from catabolic illness.
- Effect of administration of β-hydroxy-β-methyl butyrate-enriched formula after liver transplantation: A pilot randomized controlled trial
PubMed ID: 32593895
HMB formula shortened hospital LOS and improved SMI/grip after liver transplantâclinical evidence of faster recovery postâillness/surgery (HMB is leucine metabolite).
Workout performance (10)
- Improving rehabilitation in sarcopenia: a randomized-controlled trial utilizing a muscle-targeted food for special medical purposes
PubMed ID: 32961041
Improvements in gait speed and functional performance (SPPB) in sarcopenic older adults after leucine-enriched supplementation indicate better physical performance.
- Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training
PubMed ID: 8941534
HMB (a leucine metabolite) during resistance training increased strength and fatâfree massâtranslates to improved exercise outcomes.
- Effects of leucine and whey protein supplementation during eight weeks of unilateral resistance training
PubMed ID: 16686554
Eight-week training with leucine+whey produced larger strength gains than placebo â translates to improved performance capacity.
- Four-month course of soluble milk proteins interacts with exercise to improve muscle strength and delay fatigue in elderly participants
PubMed ID: 25444576
Leucineârich milk protein + training increased time to task failure and endurance in older menâimprovement in performance/endurance.
- Postexercise Dietary Protein Ingestion Increases Whole-Body Leucine Balance in a Dose-Dependent Manner in Healthy Children
PubMed ID: 28381530
Post-exercise protein (and leucine) produced dose-dependent positive whole-body leucine balance in active childrenâsupports post-exercise anabolism.
- Effects of a leucine-enriched amino acid supplement on muscle mass, muscle strength, and physical function in post-stroke patients with sarcopenia: A randomized controlled trial
PubMed ID: 30273819
In post-stroke sarcopenic patients leucine supplement improved motor function during rehabilitation (functional performance context).
- Dileucine ingestion, but not leucine, increases lower body strength and performance following resistance training: A double-blind, randomized, placebo-controlled trial
PubMed ID: 39739679
10âweek RCT: dileucine increased lowerâbody 1RM and work capacity vs free leucine/placeboâdirect exercise performance benefit.
- Collagen Protein Ingestion during Recovery from Exercise Does Not Increase Muscle Connective Protein Synthesis Rates
PubMed ID: 37202878
Whey (leucine-rich) increased contractile MPS after resistance exerciseâtranslates to functional performance potential.
- Effects of exercise and amino acid supplementation on body composition and physical function in community-dwelling elderly Japanese sarcopenic women: a randomized controlled trial
PubMed ID: 22142410
In sarcopenic elderly, leucine-rich supplement + exercise improved walking speed and knee-extension strengthâfunctional performance gain.
- Dose-response effects of dietary protein on muscle protein synthesis during recovery from endurance exercise in young men: a double-blind randomized trial
PubMed ID: 32359142
Demonstrated a protein dose that maximizes myofibrillar protein synthesis after exercise â informs protein/leucine dosing to support adaptation.
Immune support (5)
- Whey protein, amino acids, and vitamin D supplementation with physical activity increases fat-free mass and strength, functionality, and quality of life and decreases inflammation in sarcopenic elderly
PubMed ID: 26864356
Trial lowered inflammation (CRP) alongside muscle/strength gains; anti-inflammatory effects may support immune resilience.
- Parenteral administration of different amounts of branch-chain amino acids in septic patients: clinical and metabolic aspects
PubMed ID: 9118656
Randomized trial: BCAA-enriched PN in septic ICU patients increased protein markers and was associated with lower ICU mortalityâstrong clinical signal for resilience.
- Rapid EPA and DHA incorporation and reduced PGE2 levels after one week intervention with a medical food in cancer patients receiving radiotherapy, a randomized trial
PubMed ID: 23123043
Leucineâenriched medical food in cancer patients lowered serum PGE2 (inflammatory mediator), suggesting immunoâmodulatory effects.
- Tryptophan, glutamine, leucine, and micronutrient supplementation improves environmental enteropathy in Zambian adults: a randomized controlled trial
PubMed ID: 31504110
Leucineâcontaining amino acids preserved smallâintestine villus height and correlated with MTORC1 activation in lamina propria CD4+ T cellsâgut barrier/immune relevance.
- [Impact of intravenous nutrition on plasma free amino acid spectrum and immune function for patients with sepsis]
PubMed ID: 17571315
IV mixed amino acids (includes leucine) in sepsis improved plasma AA and some immune proteins (IgM/C3/C4).
Fat burn (5)
- Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training
PubMed ID: 8941534
HMB increased fatâfree mass and was associated with decreases in percent body fat during resistance trainingâsuggests potential favorable bodyâcomposition effects.
- Gut Microbiome and Metabolome Alterations in Overweight or Obese Adult Population after Weight-Loss Bifidobacterium breve BBr60 Intervention: A Randomized Controlled Trial
PubMed ID: 39456659
RCT showed statistically greater weight loss and improved lipidsâstrongest direct signal among provided studies for fatâloss potential (via altered BCAA pathways).
- Functional and metabolic effects of omega-3 polyunsaturated fatty acid supplementation and the role of β-hydroxy-β-methylbutyrate addition in chronic obstructive pulmonary disease: A randomized clinical trial
PubMed ID: 39181037
HMB+EPA/DHA group in COPD trial showed decreases in whole-body and extremity fat mass, supporting fat-loss potential.
- The Effects of Timing of a Leucine-Enriched Amino Acid Supplement on Body Composition and Physical Function in Stroke Patients: A Randomized Controlled Trial
PubMed ID: 32610608
Stroke rehab trial showed breakfast timing of leucineârich supplement was associated with greater body fat loss versus other timing.
- Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial
PubMed ID: 26817506
Higherâprotein diet (2.4 g/kg/d) during marked energy deficit produced greater fat loss than lower protein dietâhigher protein/leucine intake associated with enhanced fat loss in this context.
Endurance (4)
- Muscle-targeted nutritional support for rehabilitation in patients with parkinsonian syndrome
PubMed ID: 31278117
Supplement during rehab improved 6MWT and preserved muscle massâtranslates to maintained stamina in parkinsonism patients.
- Effects of Leucine Administration in Sarcopenia: A Randomized and Placebo-controlled Clinical Trial
PubMed ID: 32230954
Leucine helped preserve walking time and respiratory expiratory strength vs placebo in frail older adults.
- Improving rehabilitation in sarcopenia: a randomized-controlled trial utilizing a muscle-targeted food for special medical purposes
PubMed ID: 32961041
Improvements in gait speed and SPPB indicate better functional stamina/endurance in sarcopenic elderly after leucineâenriched supplementation.
- Four-month course of soluble milk proteins interacts with exercise to improve muscle strength and delay fatigue in elderly participants
PubMed ID: 25444576
Leucineârich supplement + training increased time to task failure (muscular endurance) in older menâsupports stamina maintenance.
Skin repair (3)
- Treatment of symptomatic oral mucositis with sodium hyaluronate and synthetic amino acid precursors of collagen in patients undergoing haematopoietic stem cell transplantation
PubMed ID: 29921408
Hyaluronic acid + amino-acid spray (includes leucine) reduced mucositis severity/duration after stem-cell transplant (clinical outcome).
- Local treatment of pressure sores in the elderly: amino acid copolymer membrane versus hydrocolloid dressing
PubMed ID: 7525682
A topical aminoâacid copolymer dressing sped pressureâsore healing in elderly inpatientsâdirect woundâhealing benefit (topical, not oral leucine).
- Effect of a specialized amino acid mixture on human collagen deposition
PubMed ID: 12192323
Randomized trial: arginine+HMB+glutamine supplement increased wound collagen deposition in elderly volunteers â direct wound-healing benefit.
Appetite suppression (3)
- Consuming Lower-Protein Nutrition Bars with Added Leucine Elicits Postprandial Changes in Appetite Sensations in Healthy Women
PubMed ID: 29897544
Small leucine-enriched snack bars increased fullness and reduced prospective food consumption acutely in healthy women.
- Postprandial Glucose and Gastrointestinal Hormone Responses of Healthy Subjects to Wheat Biscuits Enriched with L-Arginine or Branched-Chain Amino Acids of Plant Origin
PubMed ID: 36297065
BCAA-enriched (high-leucine) biscuits improved gut-hormone and satiety responses compared with common wheat biscuits in humans.
- The impact of liquid preloads varying in macronutrient content on postprandial kinetics of amino acids relative to appetite in healthy adults
PubMed ID: 27544805
Postprandial elevations in BCAAs (including leucine) were inversely associated with subsequent energy intake in healthy adults â supports a role for leucine/BCAAs in reducing later intake.
Bone health (2)
- A Vitamin D, Calcium and Leucine-Enriched Whey Protein Nutritional Supplement Improves Measures of Bone Health in Sarcopenic Non-Malnourished Older Adults: The PROVIDE Study
PubMed ID: 31338563
Vitamin D + leucineâenriched whey increased 25(OH)D, lowered PTH and produced a modest but significant totalâbody BMD increase in older adults (combo product).
- Effects of Nutritional Support with a Leucine-Enriched Essential Amino Acid Supplement on Body Composition, Muscle Strength, and Physical Function in Stroke Patients Undergoing Rehabilitation
PubMed ID: 39770886
Leucineâenriched EAA in stroke patients preserved bone mineral content over 12 weeks vs rehab alone.
Focus & concentration (2)
- Efficacy and safety of N-acetyl-L-leucine in Niemann-Pick disease type C
PubMed ID: 34387740
NâacetylâLâleucine improved neurologic function and clinician/patient global impressions in NiemannâPick type Câdiseaseâspecific cognitive/motor benefit (derivative compound).
- Medium-Chain Triglycerides in Combination with Leucine and Vitamin D Benefit Cognition in Frail Elderly Adults: A Randomized Controlled Trial
PubMed ID: 28552878
Supplement containing leucine+MCT+vitamin D improved cognition (MMSE) in frail elderly; leucine may have supported neural function indirectly, though other components likely contributed.
Muscle soreness (1)
- Effect of leucine metabolite beta-hydroxy-beta-methylbutyrate on muscle metabolism during resistance-exercise training
PubMed ID: 8941534
HMB decreased plasma CPK (a muscle damage marker) and reduced exerciseâinduced proteolysis suggesting less damage/soreness.
Similar by evidence
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Products with Leucine
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Being studied right now
Recruiting clinical trials registered on ClinicalTrials.gov. A trial in progress has no result yet â this is what the field is asking, not what it found.