Coenzyme Q10—often called CoQ10—is a vitamin-like antioxidant the body makes naturally, but it’s also found in certain foods and widely available as a supplement marketed mainly for heart health and energy support. It’s also been promoted online for blood sugar control, but experts said there isn’t enough evidence showing that taking CoQ10 reliably improves glucose levels.
Overall, CoQ10 isn’t something clinicians routinely suggest for blood sugar management, according to Cecilia Low Wang, MD, an endocrinologist at UCHealth in Aurora, Colorado. It’s “not something that we hang our hat on in terms of being confident enough to recommend to our patients,” she said.
Some studies suggest CoQ10 supplementation may modestly reduce fasting blood sugar, fasting insulin, and A1C—a measure of average blood sugar levels—after eight to 10 weeks of daily use, particularly among those with prediabetes and diabetes, said Megan Wroe, MS, RD, CNE, CLEC, a wellness manager and registered dietitian at Providence St. Jude Medical Center.
But those findings come with important caveats. Many studies are short, meaning “longer-term data isn’t really there,” Wroe said. And because trials often don’t control for factors like diet, physical activity, or the presence of multiple chronic conditions, it’s difficult to determine whether CoQ10 is truly responsible for any of the positive results.
The body of evidence is also limited by small study sizes, Low Wang noted. In addition, some papers have been retracted or have received an “expression of concern” regarding the integrity of the research, she said.
Again, there’s no solid evidence linking CoQ10 to meaningful blood sugar support. But if it does have an effect, what might explain it?
“Lots of potential mechanisms for benefit have been proposed, ranging from improvements in insulin signaling to helping the function of beta cells in the pancreas,” said Rachel Pessah-Pollack, MD, FACE, an endocrinologist at NYU Langone Health.
Wroe added that COQ10’s anti-inflammatory properties—particularly when paired with lifestyle measures like a healthy diet and exercise—could play a role in blood sugar control. Some researchers also hypothesize that by protecting against mitochondrial damage, CoQ10 may help cells process glucose more efficiently.
As with any supplement, it’s best to talk with your doctor before trying CoQ10. While it’s generally considered safe, CoQ10 can interfere with some medications and therapies, especially anti-cancer therapies, Low Wang said.
When CoQ10 is used for blood sugar management, typical doses range from 100 to 200 milligrams per day, Pessah-Pollack said. Any potential benefit may be most pronounced for people with existing type 2 diabetes, she added.
Still, CoQ10 isn’t a substitute for healthy lifestyle strategies. “We know that lifestyle changes such as a heart-healthy diet are the first-line treatment for managing type 2 diabetes, based on excellent data,” said Pessah-Pollack. “While CoQ10 may have some benefit on blood sugar levels, the effects are significantly less and inconsistent compared to that which is achieved by diabetes medications and lifestyle interventions such as diet modifications, increased activity, and weight reduction.”
