Does CoQ10 help with diabetes and PCOS? What the research does and doesn't show

The evidence doesn't support CoQ10 as a treatment for diabetes or PCOS. Pooled trials in type 2 diabetes found at most a very small fall in fasting glucose and no change in HbA1c. A meta-analysis of nine PCOS trials reported changes in insulin resistance and hormones, but gave no doses.

What the evidence doesn't support

It doesn't support CoQ10 as a treatment for diabetes, insulin resistance or PCOS, or as a reason to change diabetes medicine or monitoring. It doesn't show better long-term blood sugar control: in the trials where HbA1c (the three-month average) was reported, it did not change significantly. It doesn't give a dose: the abstracts below state none. And it doesn't tell us the PCOS result is solid: the abstract doesn't say which trials were pooled for each outcome or how reliable they were.

What the trials found

Type 2 diabetes, 7 trials. A 2015 meta-analysis of seven randomised placebo-controlled trials lasting at least 12 weeks (356 patients with diabetes) found that CoQ10 alone did not improve glycaemic control, and did not alter LDL cholesterol, HDL cholesterol or blood pressure. Triglycerides were lower (-0.26 mmol/L, 95% CI -0.47 to -0.05). The authors said data were limited and dose effects needed exploring (Suksomboon 2015).

Diabetes biomarkers, 16 articles. A 2016 meta-analysis looked at fasting glucose, fasting insulin and HbA1c. The first pooled result for fasting glucose (14 studies) was unreliable because the trials disagreed so strongly (I2 93.9%). After three trials were removed, a small fall remained (standardised mean difference -0.20, 95% CI -0.38 to -0.02). HbA1c (-0.05, 95% CI -0.22 to 0.12) and fasting insulin (0.12, 95% CI -0.21 to 0.44) did not change significantly. The authors concluded that longer studies were needed (Moradi 2016). A result that appears only after trials are removed deserves caution.

PCOS, 9 trials. A 2023 systematic review and meta-analysis pooled nine randomised trials in 1,021 women with polycystic ovary syndrome. It reported HOMA-IR (an insulin resistance score), fasting glucose, testosterone (SMD -0.28, 95% CI -0.49 to -0.06), triglycerides, total cholesterol and LDL, and higher FSH and HDL. Only one trial reported adverse events, and it found none. The abstract states no dose and doesn't say which trials fed each outcome, so we can't say what any amount of CoQ10 would be expected to do (Zhang 2023).

Questions people ask

Is CoQ10 good for diabetes, and does it help with diabetes?

Not shown for blood sugar control. Seven trials found no improvement with CoQ10 alone, and another analysis found no HbA1c change. See above for the small fasting-glucose result and its caveat.

Does CoQ10 help with insulin resistance?

The PCOS meta-analysis reported a HOMA-IR score (an index of insulin resistance) that was lower. The separate diabetes analysis found no significant change in fasting insulin. The groups differ, and neither stated a dose.

Does CoQ10 help with PCOS, and what does the PCOS study show?

One 2023 meta-analysis of nine trials in 1,021 women reported changes in glucose, hormones and lipids and no adverse events in the one trial that reported them. Its abstract gives no dose, so it can't be turned into one. For other results in women, see CoQ10 for women: what the research does and doesn't show.

Which form of CoQ10 is used for diabetes?

No trial we read compared forms of CoQ10 in diabetes, so we can't rank any. Whether to add any supplement is a question for your clinician.

When to talk to a doctor

A clinician should be involved with both, and blood sugar changes need monitoring. CoQ10 is not a treatment for either. If you take diabetes medicine, a blood thinner or any other prescription, ask your prescriber or pharmacist before adding a supplement, and never change a prescribed medicine because of one.

Related reading: CoQ10 for women, CoQ10 and cholesterol, CoQ10 benefits: what the research does and doesn't show.