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📰Read the full 5-HTP evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ Patient on SSRI/SNRI/MAOI starting 5-HTP — SEROTONIN SYNDROME RISK. Stop immediately [3]
⚠ Patient on triptans for migraine + 5-HTP — serotonin syndrome risk [3]
⚠ Patient using 5-HTP for depression as SSRI substitute — evidence is weak; not appropriate for moderate-severe depression [2]
⚠ 5-HTP for insomnia: works via serotonin → melatonin conversion [2]
ℹ️ Not obtained from food. Not applicable as a daily target — obtained as part of dietary protein rather than tracked individually.
🔬 Lab interpreter
Recommended test
No routine monitoring needed for supplementation
No routine monitoring needed for supplementation
Reference range / target
N/A
N/A
Monitor clinically for mood changes and serotonergic symptoms [2].
Full lab monitoring ↓⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
5-HTP is the direct serotonin precursor that crosses the BBB freely. The MOST DANGEROUS supplement interaction: 5-HTP + SSRIs/SNRIs/MAOIs = serotonin syndrome. NEVER combine with any serotonergic drug. Evidence for depression is old and low-quality — not a proven SSRI substitute. Useful for insomnia (→ melatonin pathway) and appetite suppression at 100–300 mg/day. Always ask about concurrent medications [2] [3].
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
Safety NOT established. Avoid in pregnancy and lactation [1].
👦 Pediatric: See guidance
Not recommended for children. Safety not established [1].
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose
How to take
🍽 Timing: Divided doses for depression (50–100 mg TID). Single dose 30 min before bed for sleep. 30 min before meals for appetite [2].
💊 With food: Empty stomach for mood/sleep effects. Before meals for appetite suppression [2].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['5-HTP from Griffonia simplicifolia', 'common', 'Standard supplemental form. 50–100 mg per capsule. Quality varies — ensure standardized to ≥95% 5-HTP. Used in virtually all supplements and clinical trials [1].'] | Standard | Check label |
3 Common questions
Is 5-HTP safer than SSRIs? ▼
5-HTP is NOT a proven substitute for SSRIs in clinical depression. The trial evidence is old and low-quality [2]. More importantly, 5-HTP has a narrower therapeutic index than SSRIs — it directly floods the serotonin pathway without the self-limiting feedback mechanisms of SSRIs. It should NOT be used for moderate-severe depression as monotherapy.
Why can't I take 5-HTP with my antidepressant? ▼
5-HTP increases serotonin synthesis; SSRIs/SNRIs prevent serotonin reuptake; MAOIs prevent serotonin breakdown. Combined: excessive serotonin accumulation → serotonin syndrome (agitation, hyperthermia, clonus, tachycardia, potentially death) [3]. NEVER combine without medical supervision.
Can 5-HTP help me sleep? ▼
Yes — 5-HTP → serotonin → melatonin. Taking 100–300 mg 30 min before bed may improve sleep onset and quality [2]. However, the same serotonin-enhancing effect means it cannot be combined with SSRIs.
Can 5-HTP cause serotonin syndrome by itself? ▼
At very high doses, theoretically yes — but in practice, serotonin syndrome from 5-HTP alone at standard doses (50–300 mg/day) is extremely rare. The danger is primarily from COMBINATION with other serotonergic agents [3].
4 Clinical evidence
Strong
5-HTP is the direct precursor to serotonin — this is basic biochemistry. Oral 5-HTP reliably increases brain serotonin synthesis in human and animal studies [2]. Serotonin syndrome risk with concurrent serotonergic drugs is well-established — this is the primary safety concern [3]. HIGH
Moderate
Depression: meta-analysis of small trials (most from 1970s–1980s) showed superiority over placebo, but trials were generally low-quality and small [2]. Insomnia: 5-HTP (100–300 mg) increases REM sleep and may reduce sleep latency via serotonin → melatonin pathway [2]. Appetite suppression: one Italian RCT showed reduced caloric intake and weight loss with 750 mg/day 5-HTP [2]. Fibromyalgia: some small positive trials for pain and sleep [2]. MODERATE
Insufficient
5 Safety, toxicity & adverse events
Absolute contraindications
✕ Concurrent MAOIs, SSRIs or SNRIs — serotonin syndrome
✕ Carcinoid syndrome/tumours — excess serotonin production
Relative
⚠ Parkinson's disease on carbidopa — altered metabolism
⚠ History of eosinophilia-myalgia concern (contaminant-related) — use pharmaceutical-grade only
⚠ Pregnancy and lactation — insufficient safety data
🚩 Red flags
● Patient on SSRI/SNRI/MAOI + 5-HTP — STOP 5-HTP. Serotonin syndrome risk [3]
● Patient with agitation, hyperthermia, clonus after starting 5-HTP + serotonergic drug — serotonin syndrome; emergency [3]
● Patient self-treating severe depression with 5-HTP instead of evidence-based treatment — redirect [2]
6 Interactions
Drug interactions
SSRIs/SNRIs (fluoxetine, sertraline, venlafaxine, etc.) Major — contraindicated
Mechanism: 5-HTP increases serotonin synthesis; SSRIs/SNRIs prevent reuptake. Combined = serotonin accumulation. [3]
Effect: Serotonin syndrome: potentially fatal. [3]
Action: NEVER combine. Allow 2-week washout (5 weeks for fluoxetine) before switching [3].
MAOIs (phenelzine, tranylcypromine, selegiline) Major — contraindicated
Mechanism: MAOIs prevent serotonin breakdown. 5-HTP increases synthesis. Combined = maximal serotonin excess. [3]
Effect: Highest risk of severe serotonin syndrome. [3]
Action: ABSOLUTELY CONTRAINDICATED. Most dangerous combination [3].
Triptans (sumatriptan, rizatriptan) Major
Mechanism: Triptans are 5-HT1B/1D agonists. Combined with 5-HTP = excessive serotonergic activity. [3]
Effect: Serotonin syndrome risk. [3]
Action: Avoid concurrent use [3].
Tramadol Major
Mechanism: Tramadol inhibits serotonin reuptake. Combined with 5-HTP = serotonin excess. [3]
Effect: Serotonin syndrome risk. [3]
Action: Avoid concurrent use [3].
Supplement synergies
Vitamin B6 (PLP) · 25–50 mg P5P
PLP is the essential cofactor for AADC, which converts 5-HTP to serotonin. Adequate B6 ensures efficient conversion [1].
PLP is the essential cofactor for AADC, which converts 5-HTP to serotonin. Adequate B6 ensures efficient conversion [1].
Magnesium · 200–400 mg magnesium glycinate
Supports serotonin receptor function. Complementary anxiolytic [1].
Supports serotonin receptor function. Complementary anxiolytic [1].
7 Regulatory
United States (FDA): Dietary supplement. Was briefly removed from market in 1989 due to eosinophilia-myalgia syndrome (EMS) linked to contaminated L-tryptophan (NOT 5-HTP). Returned to market. No drug approval [1].
European Union: Available as food supplement. Some countries restrict dose per capsule [1].
Japan: Available as dietary supplement.
South Korea: Available as dietary supplement.
8 US supplement products
167
on-market products containing 5-HTP (NIH DSLD)
Brands carrying 5-HTP (102)
Click a brand to see its 5-HTP products.
9 Frequently paired with
10 Cite this page
Vancouver: Pkhakadze G. 5-HTP — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Sep 01]. Available from: https://supplement.ge/ingredients/5-htp/
APA 7th: Pkhakadze, G. (2026). 5-HTP — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/5-htp/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: March 2027
References: 3 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "5-HTP — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/5-htp/ CC BY 4.0.
GP
Prof. G. Pkhakadze, MD, MPH, PhD
Professor of Public Health · Head of Department, DTMU
Editor-in-Chief, Georgian Medical Journal (ISSN 3088-4322)
Chair, Public Health Institute of Georgia · UEMS Public Health Section
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG