5-HTP
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.
Mechanisms of Action
Serotonin Synthesis
Directly converts to serotonin in the brain
Melatonin Precursor
Serotonin converts to melatonin for sleep
Recommended Dose
50-100mg for sleep; 150-300mg for mood
Optimal Timing
- For sleep: 30-45 minutes before bed
- For mood: 2-3 divided doses with meals
Take with food
Best Form
Capsules
Alternatives: Tablets, Extended-release
Start with lower doses and increase gradually. Some prefer taking with B6 for conversion support (though not always necessary).
Duration
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.
Personalized Dosage Calculator
Get a dosage recommendation tailored to your body weight, age, goals, and health profile.
Set up your health profile for personalized recommendations
Mood Improvement
May lift mood and reduce depressive symptoms
Better Sleep
Improved sleep quality and onset
Appetite Reduction
May reduce carbohydrate cravings
Nausea
Common side effect, especially at higher doses
Avoid — may affect fetal development
Do NOT use without medical supervision
Not recommended
Who Should NOT Take This
- Currently taking SSRIs, SNRIs, MAOIs, or other serotonergic drugs
- Carcinoid syndrome
- Scleroderma
Drug Interactions
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
Possible Side Effects
Tip: Take with food; start with low dose; use ginger
Tip: Take in evening; reduce dose
Tip: Take with meals
Tip: Reduce dose
Warnings
- NEVER combine with SSRIs, SNRIs, MAOIs, or other serotonergic drugs
- Serotonin syndrome can be life-threatening
- Not a substitute for proper mental health treatment
- Long-term safety not well established
Top studies from 40+ peer-reviewed papers
Ma T et al. • Cell reports. Medicine (2025)
“All rights reserved.”
Key Findings:
- 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 improves constipation symptoms, stool straining, and worry scores.
- These findings highlight the comprehensive efficacy of Probio-Eco and provide robust evidence for its clinical application in constipation management.
- This study was registered at Chinese Clinical Trial Registry (ChiCTR2100054376).Copyright © 2025 The Authors.
- Published by Elsevier Inc.
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.”
Key Findings:
- 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.
- Future research might benefit from larger samples, better reporting of side effects and inclusion of quality of life and functioning measures.
- Further research warranted to confirm findings
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.”
Key Findings:
- Two studies only reported any primary outcomes of interest (patient-reported pain relief of 30%, or 50%, or greater).
- 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.
- Further research warranted to confirm findings
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.”
Key Findings:
- A panel of biomarkers selected from >70 differentially expressed urinary metabolites by receiver operating characteristic and logistic regression analysis provided excellent predictive power with high sensitivity and specificity for PP.
- The altered metabolic profile of the PP patients was characterized by three major perturbed metabolic pathways: catecholamine, serotonin metabolism, and tricarboxylic acid cycle, presumably resulting from activation of the sympathetic nervous system and the hypothalamic-pituitary-gonadal axis.
- Treatment with triptorelin depot was able to normalize these three altered pathways.
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.”
Key Findings:
- Systematic review examining 5-HTP efficacy
- Published in BMJ clinical evidence (2010)
- Further research warranted to confirm findings
Study Type Distribution
Goals This Supplement Supports
Related Goals
This information is for educational purposes only and is not intended as medical advice. Always consult a qualified healthcare provider before starting any supplement.