A common diabetes medication may do far more than regulate blood sugar. New research published in 2025 suggests that metformin — one of the world’s most widely prescribed drugs — could significantly increase the chances of older women living past the age of 90. The findings add to a growing body of evidence pointing to metformin’s powerful anti-aging properties, sparking renewed interest in its potential beyond diabetes management.
What the Research Reveals
Scientists from the United States and Germany analyzed data from a long-term study focused on postmenopausal women in the US. Researchers selected records from 438 participants — half of whom were treated with metformin for type 2 diabetes, and the other half treated with sulfonylurea, a different class of diabetes medication.
The results were striking. Women in the metformin group were calculated to have a 30 percent lower risk of dying before the age of 90 compared to those taking sulfonylurea. While the study has limitations, including its non-randomized design and relatively modest sample size, the longevity difference between the two groups was significant enough to warrant serious scientific attention.
“Metformin initiation increased exceptional longevity compared with sulfonylurea initiation among women with type 2 diabetes,” the researchers concluded in their published findings.
Why Metformin May Fight Aging
Metformin has been in clinical use for decades, making it one of the most well-studied medications in the world. What sets it apart from other diabetes treatments is its classification as a gerotherapeutic — a drug capable of slowing down multiple aging processes simultaneously within the human body.
Research has shown that metformin works through several key biological mechanisms that are directly linked to the aging process. It limits DNA damage, promotes gene activity associated with extended lifespan, and helps regulate cellular repair pathways that tend to deteriorate as we age. These combined effects make metformin uniquely positioned among existing medications to not just treat disease, but potentially delay the biological clock itself.
Beyond its anti-aging potential, previous studies have shown that metformin can slow cognitive wear and tear in the brain and may even lower the risk of developing long COVID — a condition increasingly associated with accelerated biological aging.
Understanding the Study’s Strengths and Limitations
Like all observational research, this study has important caveats. Because participants were not randomly assigned to treatments — they were following individualized medical advice — the study cannot confirm direct cause and effect the way a randomized controlled trial (RCT) would. There was also no placebo group receiving no treatment, and the overall sample size was modest.
That said, the study carries notable strengths that distinguish it from typical clinical research. The average follow-up period was 14 to 15 years, far exceeding what most RCTs can feasibly achieve. This extended timeline is critical for understanding how any intervention influences lifespan in a meaningful way.
“A key advantage of our analysis was the long follow-up period after treatment initiation enabled by examination of a cohort with extensive follow-up from midlife to ages 90 and older, which is not feasible in typical randomized controlled trials,” the research team noted.
What This Means for the Science of Aging
The findings arrive at a pivotal moment in medical research. As global populations continue to age rapidly, scientists are intensifying their focus on what the field calls geroscience — the study of biological aging and how slowing it might prevent or delay the onset of multiple age-related diseases and disabilities.
The geroscience hypothesis proposes that biological aging is not fixed, but malleable. If scientists can identify safe, effective interventions that slow the aging process itself — rather than targeting individual diseases one at a time — the potential impact on public health could be transformative.
“A key goal of geroscience is to identify novel therapeutic and preventive interventions that slow biological aging,” the research team wrote, framing metformin as one of the most promising candidates currently available.
What Comes Next
Researchers suggest that larger, randomized controlled trials should follow to build on and validate these findings. Such trials could provide more definitive answers about whether metformin genuinely extends human lifespan — and whether its benefits extend beyond postmenopausal women to broader populations.
In the meantime, metformin’s safety profile, low cost, and global availability make it an increasingly attractive subject for ongoing longevity research. For older women managing type 2 diabetes, the evidence is growing that their medication may be delivering benefits that go well beyond blood sugar control — quietly supporting a longer, healthier life.
