The goal of this clinical trial is to learn if 3 months of taking the dietary supplement MitoQ [a mitochondria-targeted antioxidant that targets to reduce mitochondrial reactive oxygen species (mitoROS)] works to treat age- and menopause-related reductions in brain artery (cerebrovascular) function in postmenopausal women 60 years of age or older free of clinical disease. The main questions it aims to answer are:

Does MitoQ improve cerebrovascular function in postmenopausal women?

If so, does MitoQ improve cerebrovascular function by lowering mitoROS in these arteries?

Researchers will compare MitoQ to a placebo (a look-alike substance that contains no drug) to see if MitoQ can improve cerebrovascular function by lowering mitoROS in arteries involved in brain health and function.

Participants will:

Take MitoQ (20 mg/day) or a placebo every day for 3 months

Visit the research laboratory at baseline and then after 3 months for cerebrovascular testing; there is also a check-in visit at 6 weeks, which is the halfway point

Keep track of symptoms and events during their treatment period to report to the study team

Inclusion Criteria:

• Age 60 years or older;
• Postmenopausal women defined as at least 1 year without menses as self-reported;
• Estrogen-deficient; no hormone therapies (e.g., estrogen, progesterone, testosterone, DHEA, oral contraceptives, etc.) within the previous 6 months;
• Ability to provide informed consent;
• Willing to accept random assignment to condition;
• Body mass index (BMI) ≤35 kg/m2;
• Mini-mental state examination score ≥21;
• Weight stable in the prior 3 months;
• Abstinence from antioxidant or CoQ10 therapy for 3 months; and
• Absence of clinical disease as determined by the physician of record following a medical history and blood chemistries

Exclusion Criteria:

• History of uncontrolled hypertension;
• Currently meeting aerobic exercise guidelines of ≥75 mins/week of vigorous or ≥150 mins/week of moderate intensity exercise as assessed by Modified Activity Questionnaire;
• Current smoker;
• Alcohol dependence or abuse;
• Other chronic medical conditions; and
• Subject report of blood donation within 8 weeks prior to enrolling.

The IPD will not be on a publicly available repository, however, any or all data may be made available upon reasonable request and collaboration.

We will publish a study protocol paper within the first year of the study to enhance rigor and reproducibility of trial.

Those seeking access to the data with a research question and open for collaboration will be considered.