Chaste tree for PCOS
The evidence that chaste tree (Vitex agnus-castus) helps polycystic ovary syndrome is weak and disputed: a handful of small, mostly Iranian trials hint at modest benefit for menstrual regularity and metabolic markers, but no major guideline, regulator, or clinic endorses it for PCOS, so it should not be relied on as a treatment.
Why this grade7-layer evidence engine
The direct human evidence is thin and comes almost entirely from small single-center Iranian trials. Only one placebo-controlled RCT specifically studied PCOS (PMID 41428718, n=60, 12 weeks), reporting modest improvements in antioxidant capacity, HDL, insulin resistance (HOMA-IR), and menstrual frequency. The remaining trials compared chaste tree against active drugs rather than placebo: PMID 28208942 (n=120) found it comparable to metformin for irregular cycles with fewer side effects, and review articles (PMID 31741280, PMID 25524718) describe lowered LH, prolactin, and testosterone but explicitly call for higher-quality studies.
Crucially, mainstream authorities are silent on PCOS specifically. The WHO supports chaste tree only for PMS, hyperprolactinaemia, luteal insufficiency, and cyclic mastalgia, and EU regulators recognize a well-established use solely for PMS at around 20 mg/day. The US FDA has issued warning letters treating disease claims for Vitex products as illegal, and the Mayo Clinic mentions chasteberry only for PMS while noting few studies show herbs work; it does not address PCOS at all.
Together this is a textbook weak-evidence, disputed picture: a plausible hormonal mechanism plus a few small positive trials, but no large or Western trials and no guideline or specialist endorsement for PCOS. Doses and preparations vary widely, drug interactions (notably with oral contraceptives) are a concern for this population, and it must be avoided in pregnancy. People with PCOS should treat chaste tree as unproven for this condition and prioritize guideline-backed options under medical supervision.
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 = 0.485
- 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 1 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status