5-Hydroxytryptophan
Direct serotonin precursor that may support mood, sleep, and appetite control, but requires caution with certain medications.
5-HTP is the immediate precursor to serotonin, the neurotransmitter associated with mood, sleep, and appetite. Derived from the seeds of Griffonia simplicifolia, it crosses the blood-brain barrier and converts directly to serotonin. Can be effective for mood support and sleep, but interactions with serotonergic medications are a serious concern.
Directly converts to serotonin in the brain
Serotonin converts to melatonin for sleep
How 5-HTP works — from molecular targets to health outcomes. Click an edge to see supporting research.This visualization is in beta — pathways are being refined and expanded.
50-100mg for sleep; 150-300mg for mood
Take with food
| Form | Type |
|---|---|
| 💊Capsules | Recommended |
| 💊Tablets | Alternative |
| 💊Extended-release | Alternative |
Start with lower doses and increase gradually. Some prefer taking with B6 for conversion support (though not always necessary).
Minimum: 2 weeks
Optimal: 4 weeks
Cycling: Not intended for long-term continuous use. Use for specific periods (4-8 weeks), then take breaks. Long-term safety data is limited.
Note: Taking with a carbohydrate may improve brain uptake. For sleep, take in evening. For mood, divide doses throughout day.
May lift mood and reduce depressive symptoms
Improved sleep quality and onset
May reduce carbohydrate cravings
Common side effect, especially at higher doses
Avoid — may affect fetal development
Do NOT use without medical supervision
Not recommended
Risk of serotonin syndrome — potentially life-threatening
Risk of serotonin syndrome
Both increase serotonin; dangerous combination
Additive serotonergic effects
May increase 5-HTP effects and side effects
Serotonin syndrome risk
Severe serotonin syndrome
Risk of serotonin syndrome
Tip: Take with food; start with low dose; use ginger
Tip: Take in evening; reduce dose
Tip: Take with meals
Tip: Reduce dose
Top studies from 38+ peer-reviewed papers
Ma T et al. • Cell reports. Medicine (2025)
“A randomized, double-blind, placebo-controlled crossover trial involving 110 adults with chronic constipation (Rome IV criteria) demonstrates that a 3-week Probio-Eco intervention significantly imp...”
Bertolini F et al. • The Cochrane database of systematic reviews (2022)
“This review provides uncertain evidence only regarding the use of hydrocortisone, propranolol, dexamethasone, omega-3 fatty acids, gabapentin, paroxetine, PulmoCare formula, Oxepa formula, or 5-hydroxytryptophan as universal PTSD prevention strategies.”
Thorpe J et al. • The Cochrane database of systematic reviews (2018)
“There are few, large, high-quality trials comparing combination pharmacotherapy with monotherapy for fibromyalgia, consequently limiting evidence to support or refute the use of combination pharmacotherapy for fibromyalgia.”
Qi Y et al. • Molecular & cellular proteomics : MCP (2012)
“Additionally, significant changes in the urine levels of 4-hydroxyphenylacetic acid, 5-hydroxyindoleacetic acid, indoleacetic acid, 5-hydroxytryptophan, and 5-hydroxykynurenamine in the CPP group suggest that the development of CPP condition may involve an alteration in symbiotic gut microbial composition.”
Bruni O et al. • BMJ clinical evidence (2010)
“In this systematic review we present information relating to the effectiveness and safety of the following interventions: antihistamines; behavioural therapy plus antihistamines, plus benzodiazepines, or plus chloral and derivatives; benzodiazepines alone; exercise; extinction and graduated extinction; 5-hydroxytryptophan; light therapy; melatonin; safety/protective interventions for parasomnias; scheduled waking (for parasomnias); sleep hygiene; and sleep restriction.”
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