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2.5/5 Weak evidence

Sleep / recovery evidence brief

L-tryptophan

L-tryptophan has sleep-latency and sleep-quality research, but that does not establish direct strength, hypertrophy, or training-recovery benefits.

Sleep signal, not gym proof recovery / health / focus 6 linked sources Content audit 2026-05-04

Headline Finding

Sleep meta-analysis supports a sleep-quality signal, especially at 1 g or more, not direct gym adaptation.

Dose Context

Sleep studies often use at least 1 g near bedtime; dietary protein, tryptophan-enriched foods, and standalone capsules are different interventions.

Important Caveat

Sedation, medication interactions, serotonin-related cautions, and next-day effects need careful consumer guidance.

Source Drawer

Linked Research

6 papers and evidence links - audit 2026-05-04
  1. Meta-analysis Sleep meta-analysis
  2. Meta-analysis Sleep meta-analysis full text
  3. Review Insomnia review
  4. Review Sleepiness/sleep review
  5. Trial Chronic insomnia trial
  6. Trial Low-dose sleep trial

How To Read This Rating

The score reflects evidence that the supplement does its stated job. Some jobs are direct, such as strength, endurance, or recovery; others are indirect, such as sleep, mood, appetite, or health support. A real effect can still receive a cautious practical rating when dose, safety, product quality, or audience fit remain uncertain.

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