5-HTP

Research records

Historical source snapshot. Not freshly verified, not a recommendation. Study findings, community accounts and app defaults are not interchangeable.

Publication suitability · 2026-10-15: Historical reference only; not a clinical verification. Clinical, regulatory, efficacy, safety and dose claims are not independently established by this review.

5-HTP

A serotonin precursor studied for mood, with a thin base of quality trial evidence.

Evidence category: Systematic review. This describes the source category, not approval or certainty.

Regulatory statement in source: Not separately recorded; do not infer approval from the evidence category.

5-HTP, or 5-hydroxytryptophan, is a naturally occurring amino acid derivative and an intermediate step in the body's conversion of tryptophan into serotonin. It has been studied mainly as a potential aid for mood and sleep, with most available trials being small, short, and methodologically limited. A Cochrane systematic review found that only a small fraction of identified studies met quality standards for inclusion, leaving the overall evidence base thin despite decades of interest.

Benefits reported in the imported source

• Small clinical trials suggest possible short-term improvement in depressive symptoms compared with placebo
• As a direct serotonin precursor, its proposed mechanism of action is biologically plausible and well characterized

Risks and limits

• Combining it with antidepressants or other serotonergic drugs raises the risk of serotonin syndrome
• Most supporting trials are small, old, and short in duration, so long-term safety and effectiveness are not established
• Nausea and other gastrointestinal upset are commonly reported side effects

Source bottom line: Evidence for 5-HTP remains preliminary: early trials look promising but a formal Cochrane review found too few high-quality studies to support confident use, and it carries meaningful interaction risk with serotonergic medications.

Uncertainty: Reference information only. Not medical advice.

Study protocols — reports, not instructions

Community and practice descriptions

Accounts of a practice are not evidence of safety or effectiveness. Words such as “standard”, “safe” or “recommended” describe the source account, not verified consensus or this wiki’s advice. Commercial and self-published citations are retained for traceability, not vendor endorsement or independent clinical corroboration.

Pharmacokinetic context

Historical half-life estimate: 2.2–7.4 hours. Neurotransmitter precursor pharmacokinetics reviewed in the Cochrane background; range spans dose and formulation differences across the small human PK literature Population/route context and estimates may differ. This is not a schedule or a verified human dosing rule.

Source references

• Tryptophan and 5-hydroxytryptophan for depression - PubMed (Cochrane review)
• Tryptophan and 5-Hydroxytryptophan for depression | Cochrane