Tryptophan and 5-hydroxytryptophan for depression
Shaw K, Turner J, Del Mar C
Published in Cochrane Database of Systematic Reviews
Methodology
Cochrane systematic review and meta-analysis of randomized trials of tryptophan and 5-HTP versus placebo in unipolar depression.
Key Findings
Of 108 identified trials, only 2 met quality criteria (64 patients total). Pooled results favoured 5-HTP/tryptophan over placebo for depressive symptoms, but the evidence base was tiny and of poor methodological quality. Adverse effects included dizziness, nausea and diarrhoea, and tryptophan has been associated with eosinophilia-myalgia syndrome.
Conclusions
5-HTP and tryptophan may be better than placebo for depression, but the evidence is insufficient to recommend them over conventional antidepressants.
Limitations
Only 2 of 108 trials were of acceptable quality; total sample of 64; short durations; safety concerns not adequately characterized.
Supplements Studied
Only 2 of 108 identified trials met quality criteria: 5-HTP outperformed placebo on depressive symptoms, but across just 64 patients.
Available evidence suggests tryptophan and 5-HTP are better than placebo for depression, but the quality of studies is insufficient to support clinical use.
Outcomes Measured
Only two of 108 identified trials were of adequate quality; these showed a benefit over placebo but the evidence was too weak to recommend routine use
Related Health Concerns
Study Details
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Disclosures
Funding
Cochrane Collaboration; no commercial funding.
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