Last verified: 17 days ago
5-HTP (5-Hydroxytryptophan)
Also known as: 5-Hydroxytryptophan, oxitriptan, L-5-HTP, 5-hydroxy-L-tryptophan
Evidence under review. — Not yet rated
Serotonin precursor that may support mood, sleep, and appetite. Evidence is limited and mostly preliminary.
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What it does
5-HTP is a naturally occurring amino acid and chemical precursor to serotonin, a neurotransmitter that regulates mood, sleep, and appetite. Your body makes 5-HTP from tryptophan found in food, and...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
50-300 mg daily (general knowledge; no dose established from provided studies)
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Found in
What the Science Says
5-HTP is a naturally occurring amino acid and chemical precursor to serotonin, a neurotransmitter that regulates mood, sleep, and appetite. Your body makes 5-HTP from tryptophan found in food, and supplementing it may help raise serotonin levels in the brain. It is most commonly used to support mood, improve sleep quality, and reduce appetite, though the clinical evidence base from the provided research is very limited.
What It Doesn't Do
Not a proven antidepressant — don't replace prescribed medications with it. Won't cure anxiety or depression on its own. No solid evidence it causes significant weight loss. Not a sleep medication. The one provided study focused on tryptophan in anorexia nervosa, not 5-HTP directly in healthy adults.
Evidence-Based Benefits
Raises serotonin precursor availability in the brain, which may support mood and emotional balance.
Weak EvidenceEffective at: 50-300 mg daily
May improve sleep onset and quality by boosting serotonin and melatonin production.
Weak EvidenceEffective at: 100-300 mg before bed
May reduce appetite and calorie intake by increasing serotonin signaling related to satiety.
Weak EvidenceEffective at: 300-900 mg daily
Absorption & Bioavailability
Good — 5-HTP crosses the blood-brain barrier more readily than tryptophan and does not compete with other amino acids for transport, making it more bioavailable than dietary tryptophan. However, this is based on general pharmacological knowledge, not the provided studies.
Red Flags to Watch For
- Do NOT combine with antidepressants (SSRIs, MAOIs, SNRIs) — risk of serotonin syndrome, a potentially life-threatening condition
- Long-term safety is not well established; some animal studies raised concerns about cardiac valve issues at high doses
- Can cause nausea, diarrhea, and stomach cramps, especially at higher doses or without food
- Products vary widely in purity — some have been found contaminated with Peak X, a compound linked to eosinophilia-myalgia syndrome
- Not recommended during pregnancy or breastfeeding due to lack of safety data
Products Containing 5-HTP (5-Hydroxytryptophan)
See how 5-HTP (5-Hydroxytryptophan) is used in these analyzed products:
Frequently Asked Questions
What does 5-HTP (5-Hydroxytryptophan) do?
Serotonin precursor that may support mood, sleep, and appetite. Evidence is limited and mostly preliminary.
What is the effective dose of 5-HTP (5-Hydroxytryptophan)?
50-300 mg daily (general knowledge; no dose established from provided studies)
Is 5-HTP (5-Hydroxytryptophan) safe?
Do NOT combine with antidepressants (SSRIs, MAOIs, SNRIs) — risk of serotonin syndrome, a potentially life-threatening condition
What doesn't 5-HTP (5-Hydroxytryptophan) do?
Not a proven antidepressant — don't replace prescribed medications with it.
Research Sources
- General knowledge
- PMID: 28438641
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25