Maca for Sexual Function
Several small randomized trials suggest maca may modestly improve sexual desire and self-reported sexual function, but the evidence is preliminary and low-quality, and "maca" supplements marketed for sex have repeatedly been found adulterated with hidden prescription erectile-dysfunction drugs.
Why this grade7-layer evidence engine
Six human trials feed this grade. Small double-blind RCTs reported improved sexual desire in healthy men (PMID 12472620), better remission of antidepressant-induced sexual dysfunction in women (PMID 18801111; PMID 25954318), reduced sexual complaints in postmenopausal women (PMID 18784609), and improved IIEF/AMS scores in men with late-onset hypogonadism (PMID 36593713). Notably, none of these effects tracked with testosterone or estrogen, so the mechanism is unclear.
The signal stays preliminary because samples are tiny (n=14 to 80) and follow-up is short. A 2010 systematic review (PMID 20691074) found only four eligible RCTs and concluded the trials were too few, too small, and too methodologically weak for firm conclusions. That ceiling is why this lands at a 'preliminary evidence' tier rather than higher.
Regulators and clinics add caution, not support. The FDA warned consumers against 'Peru Maca' after finding it spiked with hidden sildenafil (the active drug in Viagra), a serious risk with nitrate medications. EU/EFSA-side bodies flag possible genotoxicity concerns, and Harvard, Cleveland Clinic, and urology/sexual-medicine societies stop at cautious, non-endorsing language. Buy from reputable sources and treat aggressive 'sexual enhancement' claims as a red flag for adulteration.
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 = 0.622
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高階證據未達主導 (0 positive vs 1 negative)，由 raw_score 決定
- 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