TAME Metformin Longevity Trial Marks a Decade With Zero Participants Enrolled

What Happened

The Targeting Aging with Metformin (TAME) trial — the study designed to test whether a cheap, off-patent diabetes drug can delay human aging — has now gone more than a decade without enrolling a single participant.

Designed by Dr. Nir Barzilai and colleagues at the Albert Einstein College of Medicine and coordinated through Wake Forest University School of Medicine, the randomized, placebo-controlled trial was to enroll more than 3,000 adults aged 65 to 79 across 14 U.S. research institutions. Its primary endpoint is a composite: time to the first occurrence of cardiovascular disease, cancer, dementia, or death.

The trial cleared its hardest regulatory step in 2015, when the FDA agreed to the design — a significant concession, because the agency does not formally recognize aging as a treatable disease. What followed was not a scientific problem but a funding stalemate. Metformin has been generic for decades, sits on the WHO Model List of Essential Medicines, and costs pennies per dose. No manufacturer profits from proving it works, so none will pay to find out. Reported budget estimates range from $45 million to $75 million — modest for a six-year study of this size, but unreachable for a drug nobody owns.

Who Is Affected

• Longevity researchers, who still lack randomized human evidence for metformin's anti-aging effects
• Older adults targeted by unverified anti-aging metformin claims, since observational data from diabetic populations does not transfer to healthy users — and clinical data suggests metformin can blunt some cardiovascular adaptations to exercise in older adults
• The geroscience field, which lost its flagship attempt to establish aging itself as a regulatory target

Timeline

• 2015 — the FDA agrees to the trial design and its composite endpoint
• 2015–2024 — years spent in NIH funding negotiations; a private donor reportedly withdrew after losing his fortune; the National Institute on Aging set aside roughly $5 million, far short of what the study needs
• September 2026 — the trial remains fully designed, regulatory-ready, and unfunded, with zero participants enrolled. Meanwhile the federally funded VITAL-H trial ($38 million, 726 adults testing rapamycin, dapagliflozin, and semaglutide for healthspan) is proceeding

What This Means for Researchers

• TAME has produced no efficacy results, because it has never run. Any claim that the trial showed metformin slows aging is false.
• The case for metformin still rests on observational studies in diabetic populations — weaker evidence than the randomized trial that was proposed precisely to settle the question.
• One result did survive: the FDA's acceptance of a composite endpoint targeting aging as an intervention, a regulatory template later trials can reuse.
• The funding failure is structural. Repurposing off-patent drugs is chronically underfunded because the clinical trial system rewards patent-protected products, regardless of public value.
• Gray-market sellers continue to market longevity compounds with no trial data behind the claims — unverified supply chains fill the vacuum left by unanswered science.

How to Verify Your Peptides

Whether you work with research peptides or metformin-adjacent compounds marketed for longevity, independent verification is non-negotiable:

• How independent testing works
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• Identity, purity, and fill weight explained

Safe Alternatives

• Review peer-referenced compound profiles on our research peptides pages
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Sources

Industry reports and regulatory announcements; clinical trial registries and geroscience publications, September 2026.