amino-acidEVIDENCEBUSOTC
L-Tryptophan
Essential amino acid precursor to serotonin and melatonin. Used for sleep and mood support.
Dose range500–2000mg
Half-life2h
Onset—min
Safety5/5high evidence base
Mechanism of action
Crosses BBB via LAT-1 transporter. Hydroxylated to 5-HTP → serotonin → melatonin pathway.
Benefits
Sleep onset and quality
EVIDENCEBMultiple RCTs.
Mood support
EVIDENCEBSmall RCTs.
Side effects
- Daytime drowsinesscommonmild
- GI upsetuncommonmild
Where to buy
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