Does CoQ10 get into your blood? In human trials, levels rose consistently

Does a CoQ10 supplement do anything you can measure? In a 2025 systematic review and meta-analysis of 24 studies in healthy adults, coenzyme Q10 (CoQ10) supplementation consistently raised blood CoQ10, which the authors describe as robust biochemical responsiveness (Deng 2025). Evidence for less subjective fatigue was suggestive.

Single trials add detail. Older adults doing interval training gained more lower-body strength and power with CoQ10 than with placebo (Bagheri 2025), and in a small crossover trial, 300 mg a day for 8 days improved subjective fatigue and cycling performance during a fatiguing task (Mizuno 2008). Across the review, effects on exercise performance were small and inconsistent.

Below are the protocols the trials used: who took part, the form, the daily amount, how long, and what was measured.

Trial protocols

The table reports what the trials gave their participants, taken from the abstracts. No personal regimen is recommended here.

Study	Design	People	Form	Dose & timing	Duration	What was measured	Grade
Deng 2025 (41457257)	Systematic review and meta-analysis	24 studies in healthy adults	Not stated; acute and chronic use	Varied; not reported	Varied	Blood CoQ10, exercise performance, subjective fatigue	A
Wolters 2003 (12847998)	RCT, double-blind, placebo-controlled	220 healthy free-living women, 60+	CoQ10 with multivitamins, selenium, magnesium	Amount not reported	6 months	Cholesterol-adjusted serum CoQ10	A
Bagheri 2025 (41470903)	RCT, double-blind	38 adults, 65-75, in supervised interval training	CoQ10 vs placebo	Amount not reported	8 weeks	Chair-stand strength and power, handgrip, balance, mobility, 6-minute walk	A
Sarmiento 2016 (27193497)	RCT	100 healthy, well-trained (non-elite) adults	Ubiquinol (reduced form)	200 mg/day, before strenuous exercise tests	2 weeks	Oxidative-stress markers around strenuous exercise, antioxidant status, plasma nitric oxide	A
Mizuno 2008 (18272335)	RCT, double-blind, placebo-controlled, three-way crossover	17 healthy volunteers	Oral CoQ10	100 or 300 mg/day	8 days	Maximum cycling velocity, subjective fatigue	A

Renue By Science sells CoQ10 as ubiquinol, the reduced form used in the Sarmiento trial, in liposomal capsules. Renue says CoQ10’s primary function is to generate energy within your cells. See Renue’s CoQ10 in the price table.

What the protocols have in common

Both studies here that measured blood CoQ10 found it rose. In the Wolters trial (12847998) of 220 women aged 60 and older, six months of CoQ10 combined with multivitamins, selenium and magnesium raised cholesterol-adjusted serum CoQ10 by 106% in the supplemented group, versus 31% in the control group. In the supplemented group, women who started lower rose more. In the meta-analysis (41457257), supplementation consistently increased blood CoQ10.

In the Sarmiento trial (27193497), 100 well-trained adults were split between 200 mg a day of ubiquinol and placebo for two weeks before two strenuous exercise tests. The ubiquinol group showed reductions in oxidative-stress markers (isoprostanes, 8-OHdG, oxidized LDL and hydroperoxides), a rise in total antioxidant status, and plasma nitric oxide held within a narrow range.

The doses and forms ran wide. The two trials whose abstracts state an amount gave 200 mg a day of ubiquinol (Sarmiento) and 100 or 300 mg a day of oral CoQ10 (Mizuno); the Wolters and Bagheri abstracts don’t give the amount. Durations ranged from 8 days (Mizuno) to two weeks (Sarmiento), 8 weeks (Bagheri) and six months (Wolters). What was measured split into two groups: blood CoQ10, and exercise or fatigue outcomes (cycling speed, chair-stand strength and power, grip, balance, the 6-minute walk).

Some single trials found performance effects. In Bagheri (41470903), 38 adults aged 65 to 75 did 8 weeks of supervised interval training, and the CoQ10 group made significantly greater gains than the placebo group on two chair-stand tests of lower-body strength and power. Grip strength, single-leg stand, timed up-and-go and the 6-minute walk improved in both groups, with no difference between them. In Mizuno (18272335), a three-way crossover in 17 healthy volunteers, 100 or 300 mg a day of CoQ10 or placebo was taken for 8 days; at 300 mg, subjective fatigue was lower and the change in maximum cycling velocity across a fatiguing task was higher than with placebo.

The pooled picture is more modest. In the meta-analysis, chronic supplementation showed a small benefit to performance and acute supplementation showed none; after outliers were excluded, the chronic effect was no longer stable. Aerobic endurance was significant at first but borderline after outlier exclusion, and strength and anaerobic outcomes changed little. Evidence for less subjective fatigue was suggestive and became more consistent after outliers were excluded. The authors rated certainty very low to low.