AgingPhase 2NCT04851288
Mitochondrial-targeted Antioxidant Supplementation for Improving Age-related Vascular Dysfunction in Humans
A Phase 2 study testing MitoQ in people with Aging, run by University of Colorado, Boulder at 1 site in United States.
Trial summary
The majority of cardiovascular diseases (CVD) occur in men and women ≥60 years of age. Vascular dysfunction, including endothelial dysfunction, as assessed by reduced endothelium-dependent dilation (EDD), and stiffening of the large elastic arteries (i.e., aortic and carotid artery stiffening), is a major mechanism of… Read more about this study
- Who is it for?
- Ages 60 years and olderHealthy volunteers can take part
- Conditions the study is for
- Aging
- What is being tested?
- MitoQ
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 112 participants
- Where
- 1 siteUnited States
- Study dates
- 2 Apr 2021to 31 Jul 2026
- Phase
- Phase 2
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 60 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age 60 years and over
- Ability to provide informed consent
- Willing to accept random assignment to condition
- Body mass index <40 kg/m2
- Weight stable in the prior 3 months (<2 kg weight change) and willing to remain weight stable throughout the study
- Free from alcohol dependence or abuse,
- Mini-mental stage examination score ≥21
Who cannot join
- Uncontrolled thyroid disease
- Regular vigorous aerobic (>6 bouts/week, >60 min/bout at a workload >6 METS)
- Blood donation within 8 weeks prior to enrolling in the study
Trial locations and contacts
1 site in 1 country.
United States1 site
University of Colorado Boulder
Boulder, Colorado, 80309
About this study
The majority of cardiovascular diseases (CVD) occur in men and women ≥60 years of age. Vascular dysfunction, including endothelial dysfunction, as assessed by reduced endothelium-dependent dilation (EDD), and stiffening of the large elastic arteries (i.e., aortic and carotid artery stiffening), is a major mechanism of increased risk of CVD in older adults. Excess production of ROS (reactive oxygen species) by mitochondria (mtROS) has emerged as a central feature of vascular oxidative stress with aging and driver of age-related vascular dysfunction. As such, identifying novel strategies to decrease mtROS and improve vascular function, to ultimately reduce the risk of age-related CVD, is an important biomedical objective.
MitoQ is a mitochondria-targeted antioxidant that accumulates at the inner mitochondrial membrane where it is optimally positioned to reduce mtROS. Preclinical findings showed that 4 weeks of oral MitoQ supplementation completely restored EDD in old mice, ameliorated mtROS-associated suppression of EDD, and was associated with reduced arterial mtROS, oxidative stress, and improved mitochondrial health. MitoQ therapy also reduced aortic stiffness in old mice. A recent small pilot study of older adults (n=20) found that supplementation with MitoQ was well-tolerated, improved endothelial function, and reduced plasma levels of oxidized low-density lipoprotein, a circulating biomarker of oxidative stress. Consistent with the preclinical findings, preliminary mechanistic assessments in subsets of subjects from the pilot study suggested that improved endothelial function with MitoQ was mediated by reduced endothelial cell mtROS production, associated reductions in tonic mtROS-related suppression of EDD, and improved mitochondrial health, linked in part to changes in circulating factors in the serum induced by chronic MitoQ supplementation. Lastly, MitoQ reduced aortic stiffness in older adults who exhibited age-related aortic stiffening at baseline.
The investigators are conducting a randomized, placebo-controlled, double-blind clinical trial to establish oral MitoQ (20 mg/day; MitoQ, Ltd.) for 3 months vs. placebo (n=56/group) for improving endothelial function in older men and women (≥60 years), and determine the mechanisms by which MitoQ improves endothelial function. The investigators will also assess the effect of MitoQ on aortic stiffness.
- Conditions
- Aging
- Being tested
- MitoQ, Placebo
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MitoQDietary supplement
Also called Mitoquinol
MitoQ is a biochemically modified form of ubiquinol
PlaceboDietary supplement
Each placebo capsule contains inert excipient and is identical in appearance
| Study group | Role | What they receive |
|---|---|---|
| MitoQ, 20 mg/day | Experimental | Each MitoQ capsule contains 20 mg of mitoquinol mesylate. Dosage: 20 mg orally per day for 3 months. Receives: Dietary Supplement: MitoQ |
| Placebo | Placebo comparator | Matched placebo capsules. Receives: Dietary Supplement: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change from baseline in endothelial function at 3 months
Brachial artery flow-mediated dilation
Measured: 3 months
Secondary outcomes (2)
Change from baseline in suppression of endothelial function by mitochondrial oxidative stress at 3 months
Change in brachial artery flow-mediated dilation with acute, supratherapeutic MitoQ (160mg)
Measured: 3 months
Change from baseline in aortic stiffness at 3 months
Carotid-femoral pulse wave velocity
Measured: 3 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Apr 2021
- Study start2 Apr 2021
- Primary completion1 Dec 2025
- Study completion31 Jul 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for AgingStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Investigator, Outcomes assessor
- Enrolment
- 112 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Colorado, Boulder
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute on Aging (NIA)
- Responsible party
- Principal investigator, Douglas Seals, University of Colorado, Boulder
- Investigators
- Douglas R Seals, Principal investigator, University of Colorado, Boulder
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04851288
- Sponsor's protocol ID
- 20-0502
- Other IDs
- R01AG066730
- Status last verified
- Aug 2026
- First submitted
- 7 Apr 2021
- Last updated
- 5 Aug 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
Publications
Oh ES, Opoku G, Darvish S, Craighead DH, Ostrow A, Rossman MJ, Steele CN, Struemph T, You Z, Seals DR, Chonchol M, Nowak KL. Sex Differences in Dementia and Mild Cognitive Impairment in Nondialysis CKD. Clin J Am Soc Nephrol. 2026 Mar 1;21(3):389-400. doi: 10.2215/CJN.0000000922. Epub 2025 Nov 20.
PubMed 41264372Murray KO, Berryman-Maciel M, Darvish S, Coppock ME, You Z, Chonchol M, Seals DR, Rossman MJ. Mitochondrial-targeted antioxidant supplementation for improving age-related vascular dysfunction in humans: A study protocol. Front Physiol. 2022 Sep 15;13:980783. doi: 10.3389/fphys.2022.980783. eCollection 2022.
PubMed 36187760
Study at a glance
From the registry record, last updated by the sponsor on 5 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Mitochondrial-targeted Antioxidant Supplementation for Improving Age-related Vascular Dysfunction in Humans
- ClinicalTrials.gov ID
- NCT04851288
- Acronym / sponsor ID
- 20-0502
- Conditions
- Aging
- Phase
- Phase 2
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 112 participants (actual)
- Lead sponsor
- University of Colorado, BoulderUniversity, hospital or other
- Collaborators
- National Institute on Aging (NIA)
- Study start
- 2 Apr 2021 (actual)
- Primary completion
- 1 Dec 2025 (actual)
- Study completion
- 31 Jul 2026 (actual)
- First posted
- 20 Apr 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The majority of cardiovascular diseases (CVD) occur in men and women ≥60 years of age. Vascular dysfunction, including endothelial dysfunction, as assessed by reduced endothelium-dependent dilation (EDD), and stiffening of the large elastic arteries (i.e., aortic and carotid artery stiffening), is a major mechanism of increased risk of CVD in older adults. Excess production of ROS (reactive oxygen species) by mitochondria (mtROS) has emerged as a central feature of vascular oxidative stress with aging and driver of age-related vascular dysfunction. As such, identifying novel strategies to decrease mtROS and improve vascular function, to ultimately reduce the risk of age-related CVD, is an important biomedical objective.
MitoQ is a mitochondria-targeted antioxidant that accumulates at the inner mitochondrial membrane where it is optimally positioned to reduce mtROS. Preclinical findings showed that 4 weeks of oral MitoQ supplementation completely restored EDD in old mice, ameliorated mtROS-associated suppression of EDD, and was associated with reduced arterial mtROS, oxidative stress, and improved mitochondrial health. MitoQ therapy also reduced aortic stiffness in old mice. A recent small pilot study of older adults (n=20) found that supplementation with MitoQ was well-tolerated, improved endothelial function, and reduced plasma levels of oxidized low-density lipoprotein, a circulating biomarker of oxidative stress. Consistent with the preclinical findings, preliminary mechanistic assessments in subsets of subjects from the pilot study suggested that improved endothelial function with MitoQ was mediated by reduced endothelial cell mtROS production, associated reductions in tonic mtROS-related suppression of EDD, and improved mitochondrial health, linked in part to changes in circulating factors in the serum induced by chronic MitoQ supplementation. Lastly, MitoQ reduced aortic stiffness in older adults who exhibited age-related aortic stiffening at baseline.
The investigators are conducting a randomized, placebo-controlled, double-blind clinical trial to establish oral MitoQ (20 mg/day; MitoQ, Ltd.) for 3 months vs. placebo (n=56/group) for improving endothelial function in older men and women (≥60 years), and determine the mechanisms by which MitoQ improves endothelial function. The investigators will also assess the effect of MitoQ on aortic stiffness.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| MitoQ, 20 mg/day | Experimental | Dietary Supplement: MitoQEach MitoQ capsule contains 20 mg of mitoquinol mesylate. Dosage: 20 mg orally per day for 3 months. |
| Placebo | Placebo comparator | Dietary Supplement: PlaceboMatched placebo capsules. |
Who may qualify
- Ages
- 60 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (7 listed)
- Age 60 years and over
- Ability to provide informed consent
- Willing to accept random assignment to condition
- Body mass index <40 kg/m2
- Weight stable in the prior 3 months (<2 kg weight change) and willing to remain weight stable throughout the study
Key exclusion criteria (3 listed)
- Uncontrolled thyroid disease
- Regular vigorous aerobic (>6 bouts/week, >60 min/bout at a workload >6 METS)
- Blood donation within 8 weeks prior to enrolling in the study
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| MitoQAlso: MitoquinolMitoQ is a biochemically modified form of ubiquinol | Dietary supplement | MitoQ, 20 mg/day |
| PlaceboEach placebo capsule contains inert excipient and is identical in appearance | Dietary supplement | Placebo |
Primary outcome
Change from baseline in endothelial function at 3 months
Time frame: 3 months
Brachial artery flow-mediated dilation
2 secondary outcomes
Change from baseline in suppression of endothelial function by mitochondrial oxidative stress at 3 months
Time frame: 3 months
Change from baseline in aortic stiffness at 3 months
Time frame: 3 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Aug 2026.
- Derived from this study: PubMed 41264372Oh ES, Opoku G, Darvish S, Craighead DH, Ostrow A, Rossman MJ, Steele CN, Struemph T, You Z, Seals DR, Chonchol M, Nowak KL. Sex Differences in Dementia and Mild Cognitive Impairment in Nondialysis CKD. Clin J Am Soc Nephrol. 2026 Mar 1;21(3):389-400. doi: 10.2215/CJN.0000000922. Epub 2025 Nov 20.
- Derived from this study: PubMed 36187760Murray KO, Berryman-Maciel M, Darvish S, Coppock ME, You Z, Chonchol M, Seals DR, Rossman MJ. Mitochondrial-targeted antioxidant supplementation for improving age-related vascular dysfunction in humans: A study protocol. Front Physiol. 2022 Sep 15;13:980783. doi: 10.3389/fphys.2022.980783. eCollection 2022.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Douglas R Seals principal investigator
University of Colorado, Boulder
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2 study testing MitoQ in people with Aging, run by University of Colorado, Boulder at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 7 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change from baseline in endothelial function at 3 months (time frame: 3 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04851288, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Aug 2026.