Legacy AI grade · Sources dated 2026-06-09. Not expert reviewed. Coverage is limited to the listed sources. About the new summary workflow
Coenzyme Q10 for Male Infertility
Verdict: Published with Warning
Across 5 PubMed studies, the evidence for Coenzyme Q10 in Male Infertility grades Tier C — weak evidence. Effective, but with safety or population caveats.
C 🟠 C Weak Evidence Published with Warning
Why this grade7-layer evidence engine
CoQ10 may improve semen parameters in some trials, but the Cochrane anchor (PMID 35506389, n=10,303) pools mixed antioxidants for male subfertility, not CoQ10 alone.
CoQ10-specific syntheses (PMID 40878114 MA; PMID 39830337 SR only) show modest sperm-motility signals but lack hard fertility-outcome data. Industry-linked open-label trials inflate optimism.
Tier C reflects surrogate semen-quality endpoints. Do not extrapolate antioxidant Cochrane results to CoQ10 monotherapy for infertility.
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Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.63
D
C
B
A
S
← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
C · Published with Warning
Confidence
81%
Highly consistent evidence
Evidence level
E3
Cochrane 35506389 pools mixed antioxidants not CoQ10 monotherapy
▸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 = 0.629
- 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
PubMed studies (5)L2 · primary research & systematic reviews
Antioxidants for male subfertility (Cochrane Review, pub5 update)
Finding: Antioxidants may increase live birth (12 RCTs, n=1283: OR 1.43, 95% CI 1.07-1.91; baseline 16% → 17-27%) and clinical pregnancy (20 RCTs, n=1706: OR 1.89, 95% CI 1.45-2.47, p<0.00001). However, when high-risk-of-bias studies were removed, live-birth effect lost significance (OR 1.22, 95% CI 0.85-1.75, p=0.27). GRADE: very low-certainty for live birth, low-certainty for pregnancy. Mild GI side effects more common (OR 2.70, 95% CI 1.46-4.99).
View on PubMed Efficacy and Safety of Coenzyme Q10 in Idiopathic Male Infertility: A Systematic Review and Meta-Analysis of Randomized Trials
Finding: CoQ10 significantly improved sperm concentration (MD +10.22 ×10⁶/mL, 95% CI 3.51-16.93, p=0.003), total motility (MD +4.95%, 95% CI 1.15-8.75, p=0.01), seminal volume (MD +0.17 mL, 95% CI 0.03-0.31, p=0.02), seminal CoQ10 levels, and clinical pregnancy odds (OR 6.02, 95% CI 1.97-18.41, p=0.002). Morphology improved with >3-month treatment. Live birth not pooled. Generally safe (3 of 4 studies reporting AEs found none; 1 mild transient).
View on PubMed Does coenzyme Q10 improve semen quality and circulating testosterone level? a systematic review and meta-analysis of randomized controlled trials
Finding: Significant improvements in total sperm count (SMD 13.38, 95% CI 10.43-16.33, p<0.0001), total motility (SMD 7.26, 95% CI 4.36-10.15, p<0.00001), progressive motility (SMD 6.39, 95% CI 2.73-10.04, p=0.0006), normal morphology (SMD 1.96, 95% CI 0.62-3.29, p=0.004); serum testosterone increased (SMD 0.59, p<0.00001), inhibin B increased, LH/FSH decreased. No significant change in semen volume or sperm concentration in this pooled subset. Pregnancy/live birth NOT reported.
View on PubMed Coenzyme Q10 and Male Infertility: A Systematic Review
Finding: CoQ10 monotherapy improved sperm motility in nearly all included studies; sperm concentration improved in several; morphology gains less consistent. Pregnancy data sparse: one study reported 23.8% pregnancy in CoQ10 vs 4.9% placebo; another 34.1% over ~8.4 months. 200-400 mg/day for >3 months shows the most consistent semen-parameter benefit; ubiquinol 400 mg > 200 mg in head-to-head dose comparison. No CI provided in narrative tables.
View on PubMed Coenzyme Q10 improves sperm motility and antioxidant status in infertile men with idiopathic oligoasthenospermia
Finding: Progressive motility improved (p<0.05) and total motility increased (p<0.01) after 12 weeks. Sperm concentration showed no significant improvement; morphology slightly decreased non-significantly. Seminal antioxidants (TAC, SOD, GPx) increased; ROS decreased; seminal CoQ10 rose markedly (p<0.001). Sperm parameters correlated with antioxidant indices (r 0.38-0.57). Pregnancy/live birth NOT primary endpoints.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Cautious
not generally recognized as safe and effective for the referenced uses and therefore are considered "new drugs" source↗
L4b EU EFSA
Against
a cause and effect relationship has not been established between the consumption of coenzyme Q10 and the claimed effects source↗
L4c UK NHS
Cautious
Advise people with migraine that the food supplement riboflavin (400 mg once a day) may be effective in reducing migraine frequency and intensity for some people. source↗
L4d TW TFDA / 衛福部
Cautious
訂定「食品原料輔酵素Q10 (Coenzyme Q10)之使用限制及標示規定」 source↗
L5b Mayo Clinic
Cautious
may improve sperm motility source↗
L5c Cleveland Clinic
Neutral
Male oxidative stress infertility (MOSI) is really the only condition that can be treated effectively with male fertility supplements. source↗
L5e Specialty Society (condition-mapped)
Cautious
Clinicians should counsel patients that the benefits of supplements (e.g., antioxidants, vitamins) are of questionable clinical utility in treating male infertility. source↗