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Head-to-head evidence comparison — which supplement is right for you?
CoQ10 and Selenium are closely matched across evidence, studies, and safety.
Verdict
Likely helps
16 of 20 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
18 of 23 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both CoQ10 and Selenium have evidence — compare verdict strength side-by-side.
100-300mg daily
With fatty meal
Ubiquinol (reduced form)
100-200mcg
With food
Selenomethionine (best absorbed)
2-4 weeks
4-8 weeks
8-12 weeks
4-8 weeks
4-8 weeks
Efficacy and Safety of Coenzyme Q10 Supplementation in the Treatment of Polycystic Ovary Syndrome: a Systematic Review and Meta-analysis
Reproductive sciences (Thousand Oaks, Calif.) (2023) · Meta analysis · n=1021
Only one RCT reported adverse events, and they found that patients had no adverse effects or symptoms following supplementation.
Coenzyme Q10 for heart failure
The Cochrane database of systematic reviews (2021) · Meta analysis · n=1573
Coenzyme Q10 probably reduces the risk of all-cause mortality more than control (RR 0.58, 95% CI 0.35 to 0.95; 1 study, 420 participants; number needed to treat for an additional beneficial outcome (NNTB) 13.3; moderate-quality evidence).
Antioxidants for female subfertility
The Cochrane database of systematic reviews (2017) · Meta analysis · n=6510
This suggests that among subfertile women with an expected clinical pregnancy rate of 22%, the rate among women using antioxidants would be between 27% and 33%.
Selenium, antioxidants, cardiovascular disease, and all-cause mortality: a systematic review and meta-analysis of randomized controlled trials
The American journal of clinical nutrition (2020) · Meta analysis · n=9423
However, a decreased risk with antioxidant mixtures was seen for CVD mortality when selenium was part of the mix (RR: 0.77; 95% CI: 0.62, 0.97; P = 0.02), with no association when selenium was absent.
Selenium for preventing cancer
The Cochrane database of systematic reviews (2018) · Meta analysis · n=27232
For analyses of RCTs with low risk of bias, the summary risk ratio (RR) for any cancer incidence was 1.01 (95% confidence interval (CI) 0.93 to 1.10; 3 studies, 19,475 participants; high-certainty evidence).
Selenium and prostate cancer: systematic review and meta-analysis
The American journal of clinical nutrition (2012) · Meta analysis · n=13254
Three high-quality studies included in the meta-analysis of toenail selenium and cancer risk indicated a reduction in prostate cancer risk (estimated RR: 0.29; 95% CI: 0.14, 0.61) with a toenail selenium concentration between 0.85 and 0.94 μg/g.
Based on heart failure meta-analysis (n=1573) showing mortality reduction. Effectiveness conservative due to single primary study (n=420). Take with food to reduce GI upset. Ubiquinol forms may have better absorption.
Based on Cochrane systematic review showing moderate-certainty evidence for TPO antibody reduction. Effects on thyroid hormone levels (TSH, T4, T3) were inconsistent across studies.
AI-estimated from published studies. Interpret as directional guidance.
Both CoQ10 and Selenium are closely matched — the best choice depends on your specific health goals.
For fertility support, CoQ10 has a higher relevance score (90 vs 75).
No known interactions between CoQ10 and Selenium have been documented in our database. However, always consult a healthcare provider before combining supplements.