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Head-to-head evidence comparison — which supplement is right for you?
CoQ10 vs NAC: they're closely matched on evidence (8 vs 6/10); they're alternatives for fertility support — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
CoQ10 and NAC are closely matched across evidence, studies, and safety.
Verdict
Likely helps
9 of 10 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
5 of 6 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both CoQ10 and NAC have evidence — compare verdict strength side-by-side.
100-300mg daily
With fatty meal
Ubiquinol (reduced form)
600-1800mg daily
Away from food, Split into 2-3 doses
NAC capsules or powder
4-12 weeks
8-12 weeks
4-8 weeks
2-8 weeks
4-8 weeks
2-4 weeks
1-2 weeks
Immediate
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
Meta-analysis of 9 randomised trials with 1,021 women with polycystic ovary syndrome.
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%.
Efficacy of N-Acetylcysteine in Polycystic Ovary Syndrome: Systematic Review and Meta-Analysis
Nutrients (2025) · Meta analysis · n=2515
Twenty-two studies (n = 2515) were included.
Efficacy of N-acetylcysteine for patients with depression: An updated systematic review and meta-analysis
General hospital psychiatry (2024) · Meta analysis · n=904
Our findings indicate that adjunctive NAC can ameliorate depressive symptoms in patients with psychiatric problems, particularly bipolar disorder.
N-acetylcysteine as a treatment for substance use cravings: A meta-analysis
Addiction biology (2024) · Meta analysis · n=623
The most targeted substance in the clinical trials was alcohol (3/9; 33.3%), followed by tobacco (2/9; 22.2%) and multiple substances (2/9; 22.2%).
Three pooled analyses tie a dose to a result. A meta-analysis of 13 studies in 4,155 patients (PMID 26324807) found fewer exacerbations with NAC (RR 0.75), with 600 mg a day sufficient in chronic bronchitis without airway obstruction and doses above 600 mg (it recommends 1,200 mg or more) also effective in spirometry-confirmed COPD (RR 0.75). Adverse reactions were not dose-dependent. A meta-analysis of 775 patients on NAC and 789 on placebo (PMID 31598901) found RR 0.81 and says under 1,200 mg a day for at least 3 months seems effective. A network meta-analysis of 7 trials in 2,753 COPD patients (PMID 31133026) at 1,200 mg a day found NAC shortened exacerbations but, unlike erdosteine, did not reduce the risk of having one, and it was well tolerated. No source shows a larger effect at 1,200 mg than at 600 mg, so the curve stays flat. 1,200 mg is the highest dose these sources report.
AI-estimated from published studies. Interpret as directional guidance.
Both CoQ10 and NAC are closely matched — the best choice depends on your specific health goals.
For fertility support, CoQ10 has a higher relevance score (90 vs 25).
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
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The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.