Saw Palmetto for Androgenetic Alopecia
Small early trials suggest saw palmetto (Serenoa repens) may modestly improve male androgenetic alopecia, but the evidence is low-quality and far weaker than for finasteride, so it cannot be considered a proven treatment. Major dermatology and health authorities do not recommend it.
Why this grade7-layer evidence engine
The grade reflects a consistent but thin positive signal. Four PubMed reports all point the same way: a 2020 systematic review (PMID 33313047) found every included androgenetic-alopecia study reported benefit (roughly 60% improvement in hair quality, 27% rise in hair count), and small RCTs echoed this, including a double-blind pilot (PMID 12006122, 60% vs 11% responders) and a topical-extract trial (PMID 26010505, modest density gains). The review itself, however, judged the overall evidence quality as limited.
It stays preliminary rather than higher because the studies are small (n=26-100), several are industry-funded, and no large multicenter trial exists. The lone head-to-head trial (PMID 23298508) is telling: over two years finasteride 1 mg clearly outperformed saw palmetto 320 mg (68% vs 38% improvement), so saw palmetto is a weaker option, not an equivalent one.
Regulators and clinicians reinforce the caution. The NIH NCCIH states the evidence is too limited to draw conclusions for male-pattern hair loss, saw palmetto is not an FDA-approved drug, and the UK NHS found it no better than placebo for prostate symptoms. Leading dermatology guidance favors minoxidil, finasteride, and laser therapy instead.
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 = 0.551
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (1 篇 > 0 negative)
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 1 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status