CoQ10

Coenzyme Q10 is a fat-soluble compound your body makes on its own. It sits inside the mitochondria of every cell. There it shuttles electrons through the respiratory chain that turns food into ATP. It also works as an antioxidant.^[1] Your body's CoQ10 levels peak in your twenties and decline after that. Tissues with high energy demand feel the drop first. The ovaries are one of those tissues.

If you have heard you should take CoQ10 for fertility or energy, this page covers the forms, dose and what the research shows.

Forms of CoQ10

CoQ10 exists in two interconvertible forms. Ubiquinone is the oxidised form used in most clinical research. Ubiquinol is the reduced form. Some studies suggest ubiquinol is absorbed slightly better in older adults whose conversion has slowed. The difference in healthy women under 50 is small. Both raise blood CoQ10 levels at adequate doses.^[1]

CoQ10 is fat-soluble. Absorption is poor on an empty stomach. Taking it with a meal that contains fat improves uptake several-fold. Splitting larger doses across two meals raises blood levels more than a single dose at the same total amount.^[1]

One context to flag is statins. They reduce endogenous CoQ10 synthesis. Whether supplementing helps statin-related muscle symptoms is still debated. If she takes a statin she should speak to her doctor first.^[1]

How much you need

CoQ10 is not classed as essential. Your body makes it. There is no EU recommended intake. Doses used in clinical research range widely. Most fertility trials use 200 to 600 mg per day. Cardiometabolic and energy trials often use 100 to 300 mg.^[2]

Dietary intake is small. A typical Western diet provides 3 to 6 mg per day from organ meats, oily fish and whole grains. Endogenous synthesis covers the rest until ageing slows it.^[1]

The science on women's health

Fertility and egg quality

Egg quality depends on mitochondrial function. A mature oocyte carries hundreds of thousands of mitochondria. They power meiosis. They drive fertilisation. As ovarian mitochondria age they generate more reactive oxygen species and less ATP. This is one of the leading explanations for why fertility declines with age.^[1]

A 2024 meta-analysis in Advances in Nutrition pooled 20 RCTs in 2,617 women with ovarian ageing. Antioxidants raised oocyte numbers. They lifted high-quality embryo rates. They raised clinical pregnancy rates. CoQ10 stood out as more effective than melatonin, myo-inositol or vitamins.^[2]

A 2024 meta-analysis in Annals of Medicine looked specifically at CoQ10 pretreatment in women with diminished ovarian reserve undergoing IVF or ICSI. Across six RCTs in 1,529 women, CoQ10 raised the clinical pregnancy rate (OR 1.84). It lowered cycle cancellation and miscarriage rates. The authors flagged that trial sample sizes were small.^[3] A separate network meta-analysis in Reproductive Biology and Endocrinology compared CoQ10 to DHEA and growth hormone in poor responders. CoQ10 produced the best live birth rate of the three (OR 2.36).^[4]

One honest counterpoint. A 2024 RCT in 44 women undergoing hysterectomy gave 300 mg CoQ10 for 14 days before surgery. AMH dropped in both groups. CoQ10 did not protect ovarian reserve. The window was short and the setting specific. CoQ10 is not a guarantee in every scenario.^[5]

Energy and ageing

The same biology that matters for eggs matters for the rest of the body. Mitochondrial energy output drops with age. CoQ10 is a co-factor in that process.^[1]

A 2025 meta-analysis in the Journal of Clinical Psychopharmacology pooled five RCTs in 474 patients. CoQ10 reduced depressive symptoms with a moderate effect size. The signal held across major depression, multiple sclerosis, breast cancer and polycystic ovary syndrome. The effect on fatigue scores was not significant from only two trials.^[6] The biology is consistent. The clinical data is mixed by population.

EU authorised health claims

Under EU law, no specific health claim is currently authorised for CoQ10. The European Food Safety Authority has not added CoQ10 to the permitted register. That reflects which dossiers have been submitted, not what the research shows.

Research suggests CoQ10 may support egg quality and IVF outcomes in women with diminished ovarian reserve.^[2][3] Most trials are in clinical fertility populations rather than in healthy women across the cycle. Until larger trials confirm an effect at typical supplemental doses, we do not make formal health claims for CoQ10.

References

[1] Jiang Y, Han Y, Qiao P, Ren F. Exploring the protective effects of coenzyme Q10 on female fertility. Frontiers in Cell and Developmental Biology 2025;13:1633166. doi.org/10.3389/fcell.2025.1633166

[2] Shang Y, Song N, He R, Wu M. Antioxidants and fertility in women with ovarian aging: a systematic review and meta-analysis. Advances in Nutrition 2024;15(8):100273. doi.org/10.1016/j.advnut.2024.100273

[3] Lin G, Li X, Jin Yie SL, Xu L. Clinical evidence of coenzyme Q10 pretreatment for women with diminished ovarian reserve undergoing IVF/ICSI: a systematic review and meta-analysis. Annals of Medicine 2024;56(1):2389469. doi.org/10.1080/07853890.2024.2389469

[4] Zhu F, Yin S, Yang B, Li S, Feng X, Wang T, Che D. TEAS, DHEA, CoQ10, and GH for poor ovarian response undergoing IVF-ET: a systematic review and network meta-analysis. Reproductive Biology and Endocrinology 2023;21(1):64. doi.org/10.1186/s12958-023-01119-0

[5] Micaraseth K, Tantanavipas S, Hongsakorn W, Singwongsa A. The effect of coenzyme Q10 pretreatment on ovarian reserve in women undergoing hysterectomy with bilateral salpingectomy: a randomised, double-blind, placebo-controlled trial. British Journal of Nutrition 2025;133(2):213-220. doi.org/10.1017/S0007114524003131

[6] Magalhães PLM, da Silva AMP, Maximiano MLB, et al. Effects of coenzyme Q10 supplementation on depressive symptoms and fatigue: a systematic review and meta-analysis of randomized controlled trials. Journal of Clinical Psychopharmacology 2025;46(1):93-100. doi.org/10.1097/JCP.0000000000002112