Fennel
8 benefits mapped to clinical evidence across supplements.
Dose per serving from products
127 products in our catalogue print how much Fennel a serving holds.
Most common: 50 mg to 100 mg, 37% of 127 products.
| Dose per serving | Products |
|---|---|
| 10 mg or less | 7 |
| 10 mg to 25 mg | 13 |
| 25 mg to 50 mg | 23 |
| 50 mg to 100 mg | 47 |
| 100 mg to 250 mg | 20 |
| 250 mg to 500 mg | 14 |
| over 500 mg | 3 |
Dose per serving from research
7 study groups in 7 studies say how much Fennel participants took a day.
These are the doses the studies gave. They are not a recommendation.
Most common: 100 mg to 250 mg, 29% of 7 study groups.
| Daily dose | Study groups |
|---|---|
| 50 mg to 100 mg | 1 |
| 100 mg to 250 mg | 2 |
| 250 mg to 500 mg | 1 |
| 500 mg to 1 g | 0 |
| 1 g to 2.5 g | 1 |
| 2.5 g to 5 g | 0 |
| 5 g to 10 g | 1 |
| 10 g to 25 g | 1 |
Benefit Evidence
Research sources
Digestive support (5)
- Efficacy of the herbal formula of Foeniculum vulgare and Rosa damascena on elderly patients with functional constipation: A double-blind randomized controlled trial
PubMed ID: 35339396
Elderly patients given a fennel + Rosa damascena formula had greater improvements in constipation severity and stool form versus PEG 4000 (randomized trial, but product multiāingredient).
- Curcumin and Fennel Essential Oil Improve Symptoms and Quality of Life in Patients with Irritable Bowel Syndrome
PubMed ID: 27308645
Curcumin + fennel EO capsule reduced IBS symptom severity and abdominal paināsupports a digestive benefit though multi-ingredient.
- The effect of fennel (Foeniculum Vulgare) seed oil emulsion in infantile colic: a randomized, placebo-controlled study
PubMed ID: 12868253
Fennel seed oil emulsion resolved infant colic and reduced crying consistent with improved GI function in infants.
- [The Effect of Fennel Tea Drinking on Postoperative Gut Recovery after Gynecological Malignancies Operation]
PubMed ID: 26867333
Fennel fruit tea after gynecologic laparotomy accelerated return of bowel function, reduced ileus and shortened hospital stayāstrong clinical digestive benefit.
- Heated fennel therapy promotes the recovery of gastrointestinal function in patients after complex abdominal surgery: A single-center prospective randomized controlled trial in China
PubMed ID: 32682507
Large RCT: heated fennel after abdominal surgery accelerated return of bowel function (time to flatus/defecation) and reduced fasting timeāstrong digestionārecovery evidence.
Bloating & gas (5)
- Heated fennel therapy promotes the recovery of gastrointestinal function in patients after complex abdominal surgery: A single-center prospective randomized controlled trial in China
PubMed ID: 32682507
Large RCT of heated fennel after abdominal surgery reported significant relief of abdominal distension (direct clinical evidence).
- Efficacy of the herbal formula of Foeniculum vulgare and Rosa damascena on elderly patients with functional constipation: A double-blind randomized controlled trial
PubMed ID: 35339396
Fennelācontaining formula improved constipation/stool consistency which plausibly reduces bloating (benefit shown in an RCT, but product was polyherbal).
- Curcumin and Fennel Essential Oil Improve Symptoms and Quality of Life in Patients with Irritable Bowel Syndrome
PubMed ID: 27308645
Curcumin + fennel EO capsule produced large IBS symptom improvements including bloating; fennel plausibly contributed but study is combination therapy.
- The effect of fennel (Foeniculum Vulgare) seed oil emulsion in infantile colic: a randomized, placebo-controlled study
PubMed ID: 12868253
Fennel seed oil emulsion markedly reduced infant colic (often gas-related), strongly supporting an effect on bloating/gas in infants.
- A randomized double-blind placebo-controlled trial of a standardized extract of Matricariae recutita, Foeniculum vulgare and Melissa officinalis (ColiMil) in the treatment of breastfed colicky infants
PubMed ID: 16041731
Chamomile+fennel+lemon balm extract substantially reduced crying in breastfed colicky infants; multi-herb but supports reduced infant GI discomfort.
Hormone balance (5)
- Fennel (Foeniculum vulgare) oral capsules improve endometrial thickness in infertile women following clomiphene citrate treatment
PubMed ID: 40784268
Oral fennel modestly increased endometrial thickness during clomiphene treatment (small trial; suggests an effect on reproductive tissues/hormoneāmediated parameters).
- Effect of fennel vaginal cream on sexual function in postmenopausal women: A double blind randomized controlled trial
PubMed ID: 29696061
Fennel vaginal cream produced large improvements in sexual function and is linked to improved atrophy markersāsupports local hormonal/estrogenic effects.
- Effect of Foeniculum vulgare Mill. (fennel) on menopausal symptoms in postmenopausal women: a randomized, triple-blind, placebo-controlled trial
PubMed ID: 28509813
Oral fennel capsules reduced menopausal symptom scores versus placebo, consistent with estrogen-like or hormone-modulating activity.
- Effect of Foeniculum vulgare (fennel) vaginal cream on vaginal atrophy in postmenopausal women: A double-blind randomized placebo-controlled trial
PubMed ID: 26617271
Topical vaginal 5% fennel cream improved cytology and pH in vaginal atrophy, consistent with estrogenic/local hormonal effects.
- Efficacy of fennel and combined oral contraceptive on depot medroxyprogesterone acetate-induced amenorrhea: a randomized placebo-controlled trial
PubMed ID: 24981150
Fennel capsules induced menstrual bleeding in DMPA-induced amenorrhea and improved continuation ratesāclear reproductive/hormonal effect.
Menstrual comfort (4)
- Efficacy of a Herbal Formulation Based on Foeniculum Vulgare in Oligo/Amenorrhea: A Randomized Clinical Trial
PubMed ID: 30370852
Fennelācontaining herbal tea reduced dysmenorrhea and altered bleeding/regularity in women with oligo/amenorrhea, but the product was polyherbal.
- Comparison of the effectiveness of fennel and mefenamic acid on pain intensity in dysmenorrhoea
PubMed ID: 17037712
Fennel extract performed comparably to mefenamic acid for primary dysmenorrhea in adolescents, supporting a clinically meaningful analgesic effect.
- The effect of fennel on pain quality, symptoms, and menstrual duration in primary dysmenorrhea
PubMed ID: 25085020
Oral fennel capsules reduced menstrual pain and shortened menstrual duration versus control (non-placebo control), supporting effectiveness for dysmenorrhea.
- The comparison of fennel infusion plus dry cupping versus metformin in management of oligomenorrhoea in patients with polycystic ovary syndrome: a randomised clinical trial
PubMed ID: 30856025
Fennel seed infusion plus dry cupping significantly reduced pain severity in women with oligomenorrhea (direct clinical evidence for menstrual pain relief, albeit combined therapy).
Stomach comfort (3)
- Traditional Chinese Nursing Using Fennel With Coarse Salt for Ironing and Umbilical Moxibustion for Epigastric Pain With Spleen-stomach Vacuity Cold
PubMed ID: 35951072
Fennel used with other modalities reduced epigastric pain and improved QoL; supports a role in upperāabdominal symptom relief though not isolated.
- Efficacy of the herbal formula of Foeniculum vulgare and Rosa damascena on elderly patients with functional constipation: A double-blind randomized controlled trial
PubMed ID: 35339396
Herbal formula including fennel improved constipation and stool consistency versus PEG, likely easing some dyspeptic/indigestion symptoms (polyherbal product).
- Heated fennel therapy promotes the recovery of gastrointestinal function in patients after complex abdominal surgery: A single-center prospective randomized controlled trial in China
PubMed ID: 32682507
Postoperative heated fennel relieved abdominal distension and sped GI recovery ā consistent with easing indigestion/ileus.
Inflammation (1)
- Effect of sweet fennel seed extract capsule on knee pain in women with knee osteoarthritis
PubMed ID: 32835919
Short RCT found decreased pain and disability in knee osteoarthritis after oral fennel extract, consistent with antiāinflammatory/analgesic effects (small/short study).
Relaxation (1)
- The Effectiveness of Melissa Officinalis L. versus Citalopram on Quality of Life of Menopausal Women with Sleep Disorder: A Randomized Double-Blind Clinical Trial
PubMed ID: 33465795
Fennelācontaining (lemon balm + fennel) capsule improved psychomotor/social MENQOL domains and vasomotor symptoms (improved QoL/relaxation likely, but multiāingredient).
Sleep quality (1)
- The Effectiveness of Melissa Officinalis L. versus Citalopram on Quality of Life of Menopausal Women with Sleep Disorder: A Randomized Double-Blind Clinical Trial
PubMed ID: 33465795
Fennelācontaining product improved vasomotor and QoL domains in menopausal women, which often relate to better sleep (product was multiāingredient).
Similar by evidence
Supplements the same benefits carry qualifying findings for ā a fact about the evidence graph, not a recommendation to swap.
Products with Fennel
Search all471 products whose verified label declares Fennel ā not every bottle that mentions it in a title.