Research Analysis · Drugs & supplements
Urolithin A missed both primary outcomes in older adults
ENERGIZE found no significant benefit for six-minute walk distance or maximal ATP production. Secondary endurance and biomarker signals remain preliminary and do not establish disability prevention or longer healthy life.
By Lois Rune
Published August 4, 2026 · Updated August 5, 2026 · AI-assistance disclosure
Secondary signals cannot turn two null primary outcomes into success
The active and placebo groups both improved on walking distance, leaving no significant primary difference. Maximal ATP production also did not improve significantly. Endurance and plasma-biomarker findings were secondary.
Primary outcomes
Six-minute walk distance and maximal ATP production were null.
Secondary findings
Two-month muscle endurance and four-month biomarkers showed signals.
Clinical boundary
The trial did not test disability, independence, healthspan or lifespan.
The bottom line
Among 66 selected older adults, 1,000 mg/day urolithin A for four months did not significantly improve either co-primary outcome versus placebo. The most favorable findings came from secondary muscle-endurance and plasma-biomarker analyses.
What researchers did
The trial randomized 33 participants per arm at two Seattle sites. Participants were age 65 to 90 with evidence of lower mitochondrial function; mean age was 71.7, 75.8% were women and all identified as White. The studied formulation was Mitopure/AMAZ-02.
What they found
Mean six-minute walk distance rose 60.8 m with urolithin A and 42.5 m with placebo, but the between-group comparison was not significant. Maximal ATP production did not improve significantly. Hand and leg endurance improved versus placebo at two months; selected acylcarnitines, ceramides and C-reactive protein changed at four months.
How strong is the evidence?
Randomization supports a causal test of this formulation over four months, but the small, selected sample limits generalization. The endpoint hierarchy matters: secondary endurance and biomarker findings cannot replace two null primary comparisons. A related middle-aged-adult trial also missed its peak-power primary endpoint.
What this does not show
ENERGIZE does not show prevention of mobility disability, sarcopenia treatment, preserved independence, aging reversal, healthspan extension or lifespan extension. It does not validate pomegranate products, microbiome interventions or unrelated urolithin A supplements.
Safety, regulation and conflicts
Adverse-event counts did not differ statistically and no serious adverse events were reported over four months; that cannot establish long-term safety. FDA does not approve dietary supplements for safety or effectiveness before sale. The paper disclosed substantial Amazentis employment, leadership, equity and patent interests.
What happens next
Independent trials should prespecify clinically meaningful function outcomes, recruit more diverse participants, monitor activity, run longer than four months and test whether any endurance signal persists and translates into daily function.
Educational boundary
This article does not recommend urolithin A, Mitopure, a dose or a retail product. Do not treat secondary biomarkers as personal evidence of improved mitochondrial health or use this report to replace clinical advice.
Sources, roles and limits
- ENERGIZE randomized trial (PMID 35050355) — primary older-adult performance and biomarker evidence
- Peer-reviewed full text (PMCID PMC8777576) — methods, absolute results, limitations and disclosures
- ClinicalTrials.gov NCT03283462 — registry and sponsor context; no posted results as of verification
- Related middle-aged-adult trial (PMID 35584623) — adjacent evidence, not direct replication
- FDA dietary-supplement overview — current regulation and safety context
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Disclosures and history
- August 4, 2026 — source discovery and independent verification completed before prose drafting.
- August 4, 2026 — identifiers, population, product, endpoint hierarchy, limitations, counterevidence, safety and funding reviewed claim by claim.
- Reviewed under standing publication authorization; release remains conditional on exact-head editorial, accessibility, responsive, container, deployment and production gates.
- AI-assisted research and drafting; source boundaries and final publication state are governed by the MoreYears.news editorial process.
- Corrections: no linked correction, retraction or expression of concern was identified for the featured primary record as of verification; sources will be rechecked at release and when this story is updated.