L-Tryptophan for Premenstrual Syndrome
L-tryptophan might modestly ease premenstrual mood symptoms, but the evidence is thin: a single small, decades-old trial supports it, with no replication. It should not be considered a proven PMS treatment.
Why this grade7-layer evidence engine
The entire case rests on one double-blind RCT (Steinberg 1999, PMID 10023508) in 71 women. Taking 6 g/day of L-tryptophan during the luteal phase reduced premenstrual mood symptoms more than placebo (34.5% vs 10.4% improvement on mood scales, p=0.004). The effect is encouraging but comes from a single small study, now over 25 years old, with no replication or meta-analysis specific to PMS.
Authoritative bodies have not endorsed this use. The Cleveland Clinic notes only that tryptophan 'may relieve' PMS symptoms, a single generic line on a drug page that does not appear in its dedicated PMS guidance. The NIH, Mayo Clinic, Harvard, and gynecology societies do not address it for PMS, and the US FDA lists tryptophan merely as a nutrient additive with no approved health claim.
Two cautions matter. The trial used 6 g/day, far above typical supplement doses, and high-dose tryptophan carries historical eosinophilia-myalgia concerns plus interaction risk with SSRIs and MAOIs often used for PMS/PMDD. With one unreplicated trial and no expert backing, the evidence stays weak.
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditable▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.449
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 無高階證據可裁決
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status