5-HTP
✓ Third-Party Tested✓ GMP-Certified Facility✓ FDA-Registered Facility✓ Manufactured in the USA using globally sourced ingredients✓ Gluten-Free✓ Lactose-Free✓ Allergen-Free✓ Corn-Free✓ Sugar-Free
Kasivit

5-HTP

5-HTP (5-hydroxytryptophan) from Griffonia simplicifolia seed extract in gelatin capsules, 60 count. Can interact with antidepressants and other serotonergic medicines; ask a doctor or pharmacist first.

💊Take 1 capsule daily to start; may increase to 2 capsules based on individual tolerance and as directed by your healthcare provider.
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🧪 Third-Party Tested
🇺🇸 Manufactured in the USA using globally sourced ingredients
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🔬 Evidence-Rated

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🥉

Bronze Evidence Rating

Emerging research tier · Limited human research exists on the main ingredient. This describes published research, not this product.

🛡️

This rating describes how much published human research we found on the main ingredient. It is not a test or review of this product, it does not mean the product treats or prevents any condition, and it is not medical advice. View the Evidence Standard →

Why It Works

Key Benefits

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Griffonia simplicifolia Seed Extract (5-HTP)
Contains 5-hydroxytryptophan (5-HTP) from Griffonia simplicifolia seed extract, with calcium carbonate, in gelatin capsules. 5-HTP is an intermediate in the body's conversion of tryptophan to serotonin. Suggested use: 1 capsule daily to start; may increase to 2 capsules as directed by your healthcare provider.
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Depression: Limited, Low-Quality Evidence
A Cochrane review found only two trials (64 patients) of sufficient quality for 5-HTP or tryptophan in depression; they suggested a benefit over placebo, but the authors judged the evidence insufficient to be conclusive. A 2020 meta-analysis judged the studies relatively weak. 5-HTP is not a treatment for depression.
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Sleep, Anxiety, Appetite: Small or Older Studies
The sleep study previously cited tested children with sleep terrors in an open trial. A small anxiety study used 5-HTP together with carbidopa, which is not in this product. An older obesity study used 900 mg a day in 20 patients. In recent trials, 5-HTP did not reduce fatigue in inflammatory bowel disease more than placebo and had no positive effect on distractibility.
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Serotonin Syndrome Risk with Serotonergic Medicines
Serotonin syndrome, a potentially fatal condition caused by excess serotonin, has been associated with SSRIs, SNRIs, MAOIs, tricyclic antidepressants, opioids such as tramadol, stimulants, lithium and St John's wort. Ask your prescriber or pharmacist before using 5-HTP if you take any of these or a triptan.
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Contamination Concern and Side Effects
Eosinophilia-myalgia syndrome was linked to contaminated tryptophan in 1989, and researchers disagree about contaminants in some 5-HTP products; no analysis of this product is cited. In one trial, 19.6% of adults taking 5-HTP reported fatigue, nausea or vomiting.
✅This product is for you if…
Adults who want a 5-HTP supplement made from Griffonia simplicifolia seed extract and have checked the precautions in the list below
Adults who take medicines or have a medical condition and have first asked a prescriber or pharmacist whether 5-HTP is suitable
⚠️Consult your healthcare provider if…
You take an antidepressant (SSRI, SNRI, MAOI or tricyclic) or another serotonergic medicine such as lithium or a stimulant: serotonin syndrome has been associated with these medicines, so ask your prescriber or pharmacist first
You take tramadol, fentanyl or another opioid, or a triptan for migraine: ask your prescriber or pharmacist first (opioids were among the most connected drugs in a serotonin syndrome analysis; for triptans the risk is uncertain and caution is advised)
You take St John's wort or another herbal product that affects serotonin: ask a pharmacist first
You take carbidopa or other Parkinson's disease medicines: ask your prescriber first (carbidopa blocks the conversion of 5-HTP outside the brain)
You have had eosinophilia-myalgia syndrome
You have bipolar disorder or a history of mania: ask your doctor first (a case report described mania after hydroxytryptophan was added to an MAOI)
You are pregnant or breastfeeding: no safety data were verified for this page; the supplier's caution advises consulting your healthcare provider
You are under 18: not intended for children without a doctor's advice
You take any prescribed medicine or have a medical condition: ask your prescriber or pharmacist first
You are planning surgery: tell your surgeon and anaesthetist that you take this supplement
You are allergic to gelatin, calcium carbonate or any other ingredient listed
You avoid animal products: the capsule is made of gelatin and is not vegan
Never stop or change a prescribed medicine without asking your prescriber
Formula

Ingredients & Dosages

Serving size: Take 1 capsule daily to start; may increase to 2 capsules based on individual tolerance and as directed by your healthcare provider.

Ingredient Amount Per Serving Purpose
5-HTP (5-Hydroxytryptophan, from Griffonia simplicifolia seed extract) 100 mg Direct serotonin precursor for mood, sleep quality, and appetite regulation

† Daily Value not established. Other ingredients: Gelatin (capsule), Magnesium Stearate.

Science

Clinical Evidence

Published research relevant to this product. These studies were generally not conducted on this specific product.

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A Cochrane review located 108 trials of 5-HTP or tryptophan for depression; only two trials (64 patients) were of sufficient quality. They suggested these substances were better than placebo, but the evidence was judged insufficient to be conclusive, and a possible association with the potentially fatal eosinophilia-myalgia syndrome had not been elucidated
Shaw K, Turner J, Del Mar C. Cochrane Database Syst Rev. 2002;(1):CD003198. ↗
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A systematic review of 13 investigations (7 in the full meta-analysis) of 5-HTP in depressed patients reported a depression remission rate of 0.65 with high variation between studies (I2 76%); the authors judged that current studies are relatively weak, with few placebo groups
Javelle F et al. Nutr Rev. 2020;78(1):77-88. ↗
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A review of preclinical and clinical evidence on 5-HTP for depression, with emphasis on double-blind placebo-controlled trials, also reviewed safety issues with 5-HTP, with emphasis on eosinophilia-myalgia syndrome and serotonin syndrome
Turner EH, Loftis JM, Blackwell AD. Pharmacol Ther. 2006;109(3):325-338. ↗
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A narrative review described 5-HTP as an intermediate in the synthesis of serotonin from tryptophan that bypasses the rate-limiting enzyme tryptophan hydroxylase, with about 70 percent of an oral dose reaching the bloodstream; it is a review, not a trial
Birdsall TC. Altern Med Rev. 1998;3(4):271-280. ↗
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In an open trial of 45 children aged 3 to 10 with sleep terrors, 31 randomly selected children received 5-HTP (2 mg/kg per day at bedtime for 20 days) and 29 of them responded after one month versus 4 of the 14 children without drug therapy; the study was not placebo-controlled and did not include adults
Bruni O et al. Eur J Pediatr. 2004;163(7):402-407. ↗
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Ten outpatients with anxiety disorders treated with 5-HTP and carbidopa showed a significant reduction in anxiety on three anxiety scales; the abstract describes no placebo group
Kahn RS, Westenberg HG. J Affect Disord. 1985;8(2):197-200. ↗
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In 20 obese patients randomly assigned to 5-HTP (900 mg a day) or placebo for two consecutive 6-week periods, the 5-HTP group lost weight in both periods and had lower carbohydrate intake and early satiety
Cangiano C et al. Am J Clin Nutr. 1992;56(5):863-867. ↗
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In a crossover trial of 166 patients with inflammatory bowel disease in remission and fatigue, 100 mg of 5-HTP twice daily for 8 weeks raised serum 5-HTP and serotonin but did not reduce fatigue more than placebo
Truyens M et al. Gastroenterology. 2022;163(5):1294-1305.e3. ↗
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In 18 healthy volunteers, 100 mg of Griffonia simplicifolia daily for 28 days had no significant effect on acute pain perception compared with placebo; mild transient adverse events occurred in two participants (11%)
Schlemmer AJ et al. Nutrients. 2026;18(10):1609. ↗
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In a randomised trial of 112 adults, a single dose of 5-HTP produced no significant positive effect on distractibility, and 19.6% of participants in the 5-HTP group experienced fatigue, nausea or vomiting
Jackson E et al. PLoS One. 2026;21(5):e0349512. ↗
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A review noted that tryptophan supplements were withdrawn in 1989 after an outbreak of eosinophilia-myalgia syndrome traced to contaminated synthetic tryptophan from a single manufacturer, and that no definitive cases of 5-HTP toxicity had emerged in 20 years of use, apart from one unresolved case; the authors considered a minor chromatographic peak (peak X) in some 5-HTP samples to lack credibility
Das YT et al. Toxicol Lett. 2004;150(1):111-122. ↗
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Peak X1, found in case-implicated 5-HTP and in 6 over-the-counter 5-HTP samples (0.5 to 10.3% of the amount in the case-implicated sample), was identified as 4,5-tryptophan-dione, a putative neurotoxin; the authors said this gives some cause for concern about the safety of commercial 5-HTP preparations
Klarskov K et al. J Rheumatol. 2003;30(1):89-95. ↗
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All eight commercially available 5-HTP samples analysed contained three or more contaminants of the 'peak X' family, a family of contaminants associated with eosinophilia-myalgia syndrome-like symptoms
Klarskov K et al. Adv Exp Med Biol. 1999;467:461-468. ↗
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A review described serotonin syndrome as a rare but potentially fatal adverse effect of increased CNS serotonin, associated with SSRIs, SNRIs, MAOIs, tricyclic antidepressants, stimulants, lithium, opioids, and herbal supplements such as St John's wort, taken alone or in combination
Badar A. J Family Community Med. 2024;31(1):1-8. ↗
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In a systematic review of 764 published serotonin syndrome cases, 92.9% of regular-prescription cases involved drug combinations; fentanyl and tramadol were the most connected non-antidepressant drugs in the network analysis
Blyzniuk B et al. Eur J Clin Pharmacol. 2026;82(8):210. ↗
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An American Headache Society position paper found that, with only Class IV evidence, data were inadequate to determine the risk of serotonin syndrome when triptans are added to SSRIs or SNRIs, and advised that caution is warranted given the seriousness of serotonin syndrome
Evans RW et al. Headache. 2010;50(6):1089-1099. ↗
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A case report described mania in a patient taking an MAOI after a hydroxytryptophan supplement was added, with no personal or family history of bipolar disorder
Pardo JV. Gen Hosp Psychiatry. 2012;34(1):102.e13-4. ↗
🔬 All studies referenced are peer-reviewed and published in indexed medical journals. This information is for educational purposes and does not constitute medical advice.

Kasivit 5-HTP is a dietary supplement containing 5-hydroxytryptophan (5-HTP) from Griffonia simplicifolia seed extract, with calcium carbonate, in gelatin capsules. 5-HTP is an intermediate in the body's conversion of the amino acid tryptophan to serotonin. Evidence that 5-HTP supplements help with depression, sleep, anxiety or appetite is limited and comes mostly from small or older studies. 5-HTP could interact with antidepressants and other serotonergic medicines, and contamination concerns have been reported with some 5-HTP products. Ask a doctor or pharmacist before use.*

What to know before use

  • Medicines: serotonin syndrome, a potentially serious condition caused by excess serotonin, has been associated with antidepressants (SSRIs, SNRIs, MAOIs, tricyclics), opioids such as tramadol, St John's wort and other serotonergic products; ask your prescriber or pharmacist before using 5-HTP
  • Contamination: eosinophilia-myalgia syndrome was linked to contaminated tryptophan in 1989, and researchers disagree about whether contaminants in some 5-HTP products are a concern
  • Side effects: nausea, vomiting and fatigue were reported by about 1 in 5 adults after a dose of 5-HTP in one trial
  • Evidence: limited; the studies below tested 5-HTP on its own, mostly in small groups, and no study of this product is cited

The science behind 5-HTP

Depression

A Cochrane review located 108 trials of 5-HTP or tryptophan for depression, but only two trials (64 patients) were of sufficient quality. They suggested these substances were better than placebo, but the authors judged the evidence insufficient to be conclusive and noted that a possible link with eosinophilia-myalgia syndrome had not been elucidated. A 2020 meta-analysis of 13 investigations reported a pooled remission rate of 0.65, with high variation between studies, and judged that current studies are relatively weak because few include placebo groups.

Shaw 2002 (Cochrane) · Javelle 2020

Sleep

The sleep study previously cited on this page was an open trial in 45 children aged about 3 to 10 with sleep terrors, 31 of whom received 2 mg/kg per day of 5-HTP at bedtime for 20 days; it is not a study of adult sleep. No placebo-controlled trial of 5-HTP for sleep in healthy adults was found in the PubMed searches done for this page.

Bruni 2004

Anxiety

A small study of 10 outpatients with anxiety disorders treated with 5-HTP plus carbidopa (a medicine that blocks the conversion of 5-HTP outside the brain; it is not in this product) reported lower scores on three anxiety scales. The abstract describes no placebo group.

Kahn 1985

Appetite and weight

In a 1992 study, 20 obese patients were randomly assigned to 5-HTP (900 mg a day) or placebo for two consecutive 6-week periods. The 5-HTP group lost weight and reported lower carbohydrate intake and early satiety. The study was small, and the dose was far above any amount suggested on this label; do not exceed the suggested use.

Cangiano 1992

Other recent trials

In a crossover trial of 166 people with inactive inflammatory bowel disease and fatigue, 100 mg of 5-HTP twice daily for 8 weeks raised blood 5-HTP and serotonin but did not reduce fatigue more than placebo. In 18 healthy volunteers, 100 mg of Griffonia simplicifolia extract daily for 28 days had no significant effect on acute pain perception. In a trial in 112 adults, a single dose of 5-HTP produced no positive effect on distractibility, and 19.6% of the 5-HTP group reported fatigue, nausea or vomiting.

Truyens 2022 · Schlemmer 2026 · Jackson 2026

Safety: contamination

Eosinophilia-myalgia syndrome (EMS) broke out in 1989 and was traced to contaminated tryptophan from a single manufacturer. A 2004 review found no definitive cases of toxicity from 5-HTP in 20 years of use, apart from one unresolved case, and judged that a minor peak in some samples ("peak X") lacked credibility. Other researchers identified a contaminant in that peak as 4,5-tryptophan-dione, a putative neurotoxin, in a case-implicated 5-HTP sample and in six over-the-counter samples, and reported that all eight commercial samples they analysed in 1999 contained three or more contaminants of the peak X family. No analysis of this product for these contaminants is cited here.

Das 2004 · Klarskov 2003 · Klarskov 1999

Safety: serotonin syndrome

Serotonin syndrome is a rare but potentially fatal condition caused by excess serotonin in the central nervous system, associated with SSRIs, SNRIs, MAOIs, tricyclic antidepressants, stimulants, lithium, opioids and herbal supplements such as St John's wort, taken alone or in combination. A 2026 analysis of 764 published cases found fentanyl and tramadol among the most connected non-antidepressant drugs. A review of 5-HTP supplementation covered serotonin syndrome and EMS as the main safety issues. For triptans, an American Headache Society position paper found the data inadequate to determine the risk with SSRIs or SNRIs but advised caution. A case report described mania after hydroxytryptophan was added to an MAOI.

Badar 2024 · Blyzniuk 2026 · Turner 2006 · Evans 2010 · Pardo 2012

Ingredients

Calcium (as Calcium Carbonate), 5-Hydroxytryptophan (from Griffonia simplicifolia seed extract), Gelatin (capsule), Magnesium Stearate.

Evidence Rating★★★★★Limited evidence · Few good-quality trials of 5-HTP for depression; no adult sleep trial found; serious interaction and contamination concerns; no study of this product is cited

✓ Third-party tested  ·  GMP-certified manufacturing facility (NSF International)  ·  See testing standards ›

Manufacturer: USA  | Amount: 60 capsules  | Gross Weight: 0.25 lb (113 g)

Suggested use

Take 1 capsule daily to start; may increase to 2 capsules based on individual tolerance and as directed by your healthcare provider.

Caution

Do not exceed the recommended dose. Pregnant or nursing mothers, children under 18, and individuals with a known medical condition should consult their healthcare provider before using this or any dietary supplement.

Warning

Keep out of reach of children. Do not use if the safety seal is damaged or missing. Store in a cool, dry place.

Gluten Free Lactose Free Allergen Free Hormone Free 100% Natural Antibiotic Free Corn Free Sugar Free

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

Questions

Frequently Asked Questions