Pygeum / Pygeum africanum for Benign Prostatic Hyperplasia
Pygeum africanum bark extract shows preliminary, plausible benefit for the urinary symptoms of benign prostatic hyperplasia (BPH), but the supporting evidence is old, low-quality, and has not been refreshed in over two decades. It is not a substitute for proven BPH therapies.
Why this grade7-layer evidence engine
The positive signal rests almost entirely on early pooled analyses. A 2002 Cochrane systematic review (PMID 11869585) of 18 small RCTs (n=1,562) found men were about twice as likely to report symptom improvement versus placebo (RR 2.1, 95% CI 1.4-3.1; SMD -0.8), and a parallel 2000 meta-analysis (PMID 11099686) reported nocturia down 19%, residual urine down 24%, and peak flow up 23%. A 1999 dosing RCT (PMID 10475357, n=209) showed comparable IPSS gains. These are real, directionally consistent findings, which is why the grade lands at preliminary rather than dismissive.
But the quality caveats are substantial and keep this out of the top tier. The trials averaged only ~64 days, used non-standardized extracts, and only one of 18 had adequate allocation concealment; the Cochrane review itself was later flagged as withdrawn/out-of-date, with no new RCTs from 2010-2026. A combination trial with nettle (PMID 15748367, n=49) found no significant benefit, and the most recent support (PMID 35435166, 2022 PROFIT, n=115) was an uncontrolled, industry-funded observational study with no placebo arm.
Authorities are split, reinforcing the cautious middle. A WHO medicinal-plant monograph endorses pygeum for BPH urinary complaints (100-200 mg/day), but US clinicians are more reserved: Mayo Clinic notes the data come from studies that are 'not well designed and is inconsistent' and that it is not generally prescribed, while a urology specialty-society position is against routine use. The FDA permits it as a supplement but bars any BPH treatment claims. Net: a plausible, generally well-tolerated option with weak, aging proof, best discussed alongside first-line medical therapy.
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 = 0.586
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (2 篇 > 0 negative)
- 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