Benefits
Endothelial function in older adults
In 20 healthy adults aged 60 to 79 with below-average vessel function, 20 mg/day for 6 weeks raised brachial artery flow-mediated dilation by 42% versus placebo in a crossover trial. A single 80 mg dose also improved this measure in adults whose baseline value was low. These are small trials; a larger 3-month trial has not yet published results.
Aortic stiffness in older adults
In the same 6-week crossover trial, carotid-femoral pulse wave velocity, a measure of aortic stiffness, was lower after MitoQ than placebo only in the 11 participants who started with high stiffness. This subgroup result from a small trial has not been repeated.
Lower oxidized LDL, an oxidative stress marker
Plasma oxidized LDL, a marker of oxidative stress, was lower after 6 weeks of 20 mg/day MitoQ than after placebo in older adults. Circulating inflammation markers did not change.
Muscle mitochondrial redox measures
In 22 adults aged 65 to 80, 20 mg/day for 12 weeks lowered the capacity of muscle mitochondria to release hydrogen peroxide but did not change mitochondrial respiration or the muscle's redox responses to a bout of exercise.
Mechanism of action
Targeting mitochondria
The positively charged triphenylphosphonium group is drawn across the strongly negative inner mitochondrial membrane, so MitoQ builds up several hundred fold inside mitochondria compared with outside.
Recycled antioxidant
Inside mitochondria, MitoQ is reduced by the respiratory chain to its active form, which neutralizes lipid peroxyl radicals and is then recycled, protecting mitochondrial membranes from oxidative damage.
Nitric oxide in blood vessels
By lowering mitochondrial superoxide, MitoQ may preserve nitric oxide in the vessel lining. In older adults, the gain in vessel dilation tracked with less oxidant-related suppression of vessel function.
Animal vascular findings
In old mice, MitoQ reversed age-related loss of artery dilation by reducing mitochondrial oxidants. These animal results led to the human vascular trials.
Clinical trials
Randomized, double-blind, placebo-controlled crossover trial of MitoQ 20 mg/day vs placebo for 6 weeks each (Rossman et al. 2018, Hypertension).
20 healthy adults aged 60 to 79 with brachial artery flow-mediated dilation below 6%.
Flow-mediated dilation was 42% higher after MitoQ than placebo (P<0.05) and oxidized LDL was lower (P<0.05). Aortic stiffness did not differ in the group as a whole and was lower only in the 11 participants with high baseline pulse wave velocity. Inflammation markers did not change. Well tolerated.
Randomized, double-blind, placebo-controlled crossover study of one 80 mg dose of MitoQ (Carlini et al. 2024, J Physiol).
23 middle-aged and older adults (11 exercisers, 12 non-exercisers).
MitoQ acutely raised flow-mediated dilation in non-exercisers (4.9% to 7.0%) and in anyone with a baseline value below 6%, but not in exercisers or those above 6%.
Randomized, double-blind, placebo-controlled parallel trial of MitoQ 20 mg/day vs placebo for 12 weeks (Broome et al. 2025, Redox Biol).
22 adults aged 65 to 80.
MitoQ lowered muscle mitochondrial hydrogen peroxide emission capacity but did not change mitochondrial respiration, exercise-induced peroxiredoxin oxidation, redox-sensitive kinases or exercise-induced gene responses.
Randomized, placebo-controlled crossover trial of MitoQ 20 mg/day for 6 weeks, reported together with a mouse study (Murray et al. 2026, J Physiol).
18 healthy, high-functioning adults aged 60 to 79.
No convincing effect of MitoQ on physical function measures. Exploratory subgroup analyses suggested possible effects on leg extension power and grip strength in participants aged 70 or older. In old mice, MitoQ improved grip strength, coordination and endurance.
Randomized, placebo-controlled crossover trial of MitoQ 20 mg/day for 8 weeks (Stute et al. 2026, Am J Physiol Renal Physiol).
30 middle-aged and older adults (mean age 57).
No changes in glomerular filtration measures or urinary kidney injury markers versus placebo; the authors report no sign of kidney benefit or harm.
Randomized, double-blind, placebo-controlled trial of MitoQ 40 or 80 mg/day vs placebo for 12 months (Snow et al. 2010, Mov Disord).
128 people with newly diagnosed, untreated Parkinson's disease.
No difference between MitoQ and placebo on any measure of disease progression, including the UPDRS. The trial was negative.
Randomized, placebo-controlled phase II trial of MitoQ 40 or 80 mg/day vs placebo for 28 days (Gane et al. 2010, Liver Int).
30 people with chronic hepatitis C who had not responded to or could not take standard treatment.
ALT fell from baseline in both MitoQ groups, but the change versus placebo was not significant; viral load did not change.
Published protocol for a randomized, double-blind, placebo-controlled parallel trial of MitoQ 20 mg/day for 3 months, NCT04851288 (Murray et al. 2022, Front Physiol).
Planned 90 healthy adults aged 60 or older (45 per group).
Primary outcome is brachial artery flow-mediated dilation; aortic stiffness is a secondary outcome. ClinicalTrials.gov lists the trial as completed with 112 enrolled, but no results have been posted or published.