Quercetin for Endurance
Quercetin does not provide a practically meaningful boost to endurance or aerobic capacity. High-quality evidence shows any effect is statistically detectable but trivial in size, and authoritative bodies do not recommend it as a performance aid.
Why this grade7-layer evidence engine
This claim is graded D (Counter-Evidence) because the strongest evidence converges against a useful effect. Two high-quality meta-analyses found only a trivial benefit: one reported an effect size of 0.15 (about a 2% gain; PMID 21606866), and the other found VO2max up just 1.94% and endurance performance up 0.74%, concluding quercetin is unlikely to be ergogenic (PMID 22805526).
The positive headline results come from small, low-quality trials in untrained people (n=12 each; PMID 20190352, PMID 35571883) and do not replicate in trained athletes. A 6-week double-blind RCT in endurance runners found no improvement in VO2peak, running economy, or 10 km time, despite reduced lipid peroxidation (PMID 24379709), and a 2023 systematic review reported varied findings with no ergogenic consensus (PMID 38288402).
Regulators and clinics reinforce this. The FDA addresses only food-additive safety (GRAS), not performance; EFSA rejected all of quercetin's health claims; and WHO/IARC list it only as Group 3 for carcinogenicity. NIH ODS and major clinics offer no endorsement for endurance, so quercetin should be viewed as a supplement that does not work for this purpose.
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 = 0.302
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 高品質 SR/MA 顯示 positive (3 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