Researchers analyzed 438 postmenopausal women from a long-term U.S. cohort and found that those who began metformin had an estimated 30% lower risk of dying before age 90 than women who started a sulfonylurea. The study followed participants for about 14–15 years on average. Because the analysis is observational (not randomized) and the sample size is modest, it cannot prove causation. The authors call for future randomized trials to confirm whether metformin can extend healthy lifespan.
Common Diabetes Drug Metformin Linked to Higher Odds of Women Living to 90
Researchers analyzed 438 postmenopausal women from a long-term U.S. cohort and found that those who began metformin had an estimated 30% lower risk of dying before age 90 than women who started a sulfonylurea. The study followed participants for about 14–15 years on average. Because the analysis is observational (not randomized) and the sample size is modest, it cannot prove causation. The authors call for future randomized trials to confirm whether metformin can extend healthy lifespan.
11:31 PM, 11/17/2025Health
Metformin associated with greater odds of reaching age 90 in postmenopausal women
New research from teams in the United States and Germany suggests that metformin — a widely used medication for type 2 diabetes — was associated with higher odds of surviving to age 90 among older women in a long-term U.S. cohort study.
The investigators selected medical records for 438 postmenopausal women from a larger study. About half of the women started metformin to manage their diabetes, while the other half began treatment with a sulfonylurea.
After adjusting for measured confounding factors, the authors estimated that women who initiated metformin had roughly a 30% lower risk of dying before age 90 compared with those who began a sulfonylurea.
"Metformin has been shown to target multiple pathways of aging and therefore has been postulated as a drug that may extend human longevity," the authors write. "We found that metformin initiation increased exceptional longevity compared with sulfonylurea initiation among women with type 2 diabetes."
Metformin has been used for decades and is often described as a gerotherapeutic — a drug thought to slow several biological aging processes. Laboratory and molecular studies suggest it can reduce DNA damage and alter gene-activity patterns linked with longer life. Previous research has also tied metformin to reduced neurodegenerative wear-and-tear and a lower risk of prolonged COVID symptoms.
However, the authors emphasize important limitations. This analysis is observational: participants received treatments as part of routine clinical care rather than being randomly assigned, there was no untreated placebo group, and the overall sample size was modest. These factors mean the study cannot prove a causal effect the way a randomized controlled trial (RCT) could.
At the same time, the study's long average follow-up of about 14–15 years is a notable strength, enabling assessment of outcomes across many years — something not typically feasible in standard RCTs. The researchers call for randomized trials in the future to test whether metformin can truly extend healthy lifespan.
Bottom line: The results add to growing research on drugs that might influence biological aging, but the findings are not definitive. Patients should not change or start medications based on this observational study alone and should consult their clinicians about diabetes treatment and potential benefits or risks.
Study published in: Journal of Gerontology: Medical Sciences.