Essential Amino Acids and Tryptophan: study protocols
11 study groups took Essential Amino Acids together with Tryptophan. These are the doses the studies gave. They are not a recommendation.
Dose per serving from research: Essential Amino Acids
9 study groups in 8 studies say how much Essential Amino Acids participants took a day.
These are the doses the studies gave. They are not a recommendation.
Most common: 50 g to 100 g, 67% of 9 study groups.
| Daily dose | Study groups |
|---|---|
| 10 g or less | 1 |
| 10 g to 25 g | 0 |
| 25 g to 50 g | 2 |
| 50 g to 100 g | 6 |
Dose per serving from research: Tryptophan
8 study groups in 7 studies say how much Tryptophan participants took a day.
These are the doses the studies gave. They are not a recommendation.
Most common: 1 g to 2.5 g, 75% of 8 study groups.
| Daily dose | Study groups |
|---|---|
| 500 mg to 1 g | 1 |
| 1 g to 2.5 g | 6 |
| 2.5 g to 5 g | 1 |
Commonly used together
4 of 11 study groups took Essential Amino Acids and Tryptophan with something else. Shown: what 3 or more different studies gave.
What was given together, not what works together.
| Taken with | Study groups |
|---|---|
| L-Tyrosine | 4 |
11 study groups
| Study | ||||
|---|---|---|---|---|
| The effects of tryptophan depletion on neural responses to emotional words in remitted depression 2009 · TRP+ · Adults aged 18–50: 23 unmedicated participants with remitted major depressive disorder and 20 healthy controls | 31.5 g | 1.2 g | 1 day | 43 |
| Serotonin transporter polymorphism mediates vulnerability to loss of incentive motivation following acute tryptophan depletion 2006 · TRP+ · Healthy adults with 5-HTTLPR ll or ss genotype, without a history of Axis I psychiatric disorders | 78 g | 3 g | 1 day | 30 |
| An fMRI study on the role of serotonin in reactive aggression 2011 · BAL (balanced amino acid drink containing tryptophan) · Healthy male volunteers; mean age 24.7 years; no stated diagnosed condition | 100 g | 2.3 g | 1 day | 15 |
| The short (S) allele of the serotonin transporter polymorphism and acute tryptophan depletion both increase impulsivity in men 2010 · Sham-depletion group · Healthy students, men and women aged 20–33 years | 100 g | — | 1 day | — |
| Acute tryptophan depletion attenuates conscious appraisal of social emotional signals in healthy female volunteers 2011 · Control mixture · Healthy female volunteers, aged 19–34; no stated psychiatric condition | 49.9 g | 1.92 g | 1 day | 15 |
| Reliance on habits at the expense of goal-directed control following dopamine precursor depletion 2012 · TYR drink · Healthy men and women aged 19–49 without the listed psychiatric, neurological or major medical conditions | 87.5 g | 2.5 g | 1 day | 14 |
| Reliance on habits at the expense of goal-directed control following dopamine precursor depletion 2012 · BAL drink · Healthy men and women aged 19–49 without the listed psychiatric, neurological or major medical conditions | 87.5 g | 2.5 g | 1 day | 14 |
| Time series fMRI measures detect changes in pontine raphé following acute tryptophan depletion 2011 · Control balanced amino acid diet including tryptophan · Adults aged 21–49 in remission from prior depression while taking serotonin reuptake inhibitor antidepressants | 100 g | 2.3 g | 1 day | 11 |
| Melatonin and dopamine as biomarkers to optimize treatment in phenylketonuria: effects of tryptophan and tyrosine supplementation 2014 · LNAA + placebo (LNAA phase) · Adults aged 21–51 years with classical phenylketonuria; 2 women and 8 men enrolled | 104 mg/kg | 30.6 mg/kg | 3 weeks | 10 |
| Melatonin and dopamine as biomarkers to optimize treatment in phenylketonuria: effects of tryptophan and tyrosine supplementation 2014 · LNAA + Trp/Tyr (LNAA + TT phase) · Adults aged 21–51 years with classical phenylketonuria; 2 women and 8 men enrolled | 104 mg/kg | 69.4 mg/kg | 3 weeks | 10 |
| Acute tryptophan depletion in accordance with body weight: influx of amino acids across the blood-brain barrier 2012 · Balanced amino acid load (BAL) · Healthy adults aged 21–30 years, male and female | 6.5 g | 700 mg | 1 day | 24 |