Tribulus Terrestris for Erectile Dysfunction
The evidence that Tribulus terrestris treats erectile dysfunction is weak, inconsistent, and low-quality, and it should not be used in place of proven therapies such as PDE5 inhibitors. Major medical authorities do not endorse it for ED.
Why this grade7-layer evidence engine
The trial record is genuinely split, which is why this lands at the lowest evidence tier rather than a clean positive. A 2026 meta-analysis of 8 RCTs (PMID 40360723) did report a statistically significant gain on the IIEF-5 (MD 4.21), and the largest individual trial, Kamenov 2017 (n=180, double-blind; PMID 28364864), found a modest improvement of 2.70 IIEF points. But a 2025 systematic review (PMID 40219032) graded the overall evidence as low quality, with erectile function improving in only 3 of 5 studies and no reliable testosterone effect.
The positive signal does not hold up under scrutiny. A double-blind RCT (PMID 24630840) found Tribulus no better than placebo (p=0.79), and a 2018 multicenter trial (PMID 29901295) lacked any placebo arm, so its ~5.5-point gain cannot establish cause. Extract standardization varies between trials and the proposed testosterone mechanism is unconfirmed, leaving the effect biologically unexplained and unstable across studies.
Independent medical sources reinforce the cautious read. Mayo Clinic states that studies of natural ED supplements show 'they just don't work,' and Harvard Health and the EU's EFSA likewise do not back it; the US FDA flags sexual-enhancement supplements as a category prone to undeclared drug adulteration. The practical takeaway: any benefit is small and unreliable, and Tribulus is not a substitute for evidence-based ED treatment.
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 = 0.385
- 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 + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status