5-Hydroxytryptophan
Direct precursor to serotonin. Crosses the blood-brain barrier and is decarboxylated to 5-HT (serotonin). Unlike tryptophan, bypasses the rate-limiting tryptophan hydroxylase step.
This compound sits in research-grey territory. The caveats below carry more weight than for FDA-approved entries — read them.
Evidence: depression (comparable to SSRIs in small trials, but NOT a replacement), fibromyalgia pain (emerging), and appetite suppression. Not to be combined with SSRIs or SNRIs (serotonin syndrome risk). In peptide stacks, 5-HTP is used for mood stabilization and sleep quality. Timing: take 30–60 min before sleep for serotonin → melatonin conversion benefit. Long-term use may deplete dopamine precursors — often stacked with L-DOPA or tyrosine to balance.
CONTRAINDICATED with SSRIs, MAOIs, SNRIs, tramadol — serotonin syndrome risk. GI upset at higher doses. Long-term use without dopamine precursor balance may worsen mood over time. Eosinophilia-myalgia syndrome (EMS) risk is low with reputable 5-HTP sources but verify sourcing.
External links to PubMed searches, ClinicalTrials.gov, and FDA materials. We do not host papers — we point at canonical sources.
Dietary supplement (DSHEA). Not FDA-approved as a drug. The 1989 EMS outbreak was linked to a contaminated tryptophan batch (not 5-HTP itself) but drove regulatory scrutiny.
Distilled themes from named communities — Reddit threads, forums, creator commentary. Not direct quotes; not clinical evidence. Useful for calibrating expectations against what real self-experimenters report.
Used in sleep stack with melatonin + magnesium. Most users report mood improvement at 100 mg but flag nausea at higher doses. Users on SSRIs universally warned not to combine.