In a multi-institutional study published online in the Journal of Gerontology: Medical Sciences on May 19, 2025 researchers examined the relationship between metformin use and a longer lifespan among postmenopausal women with type 2 diabetes. When compared with sulfonylurea, another class of diabetes medication, they reported that using metformin increased the likelihood of reaching an age of 90 or older, known as exceptional longevity.

The study's key finding is that the use of metformin is associated with a 30% lower risk of death before age 90 compared to use of sulfonylurea. However, because metformin was not compared to a placebo, future studies are needed to determine the underlying cause of this association.

Researchers analyzed data from the Women’s Health Initiative (WHI), a large, national cohort study with over 30 years of follow-up, funded by the National Heart, Lung, and Blood Institute at the National Institutes of Health (NIH).

The WHI, which recently had its NIH funding reinstated, has led groundbreaking research in women’s health since the 1990s, generating findings that have shaped clinical practice and public health policies in the United States. Some key facts about WHI:

161,808 women (ages 50-79) were enrolled in WHI’s studies in the mid-1990s across 40 clinical centers nationwide.
Over 42,000 participants (ages 78-108) remain actively involved today.
WHI provides a unique and comprehensive resource for studying disease risks, early detection, prevention and aging-related health outcomes.
It has resulted in over 2,400 scientific publications exploring key aging-related health factors.

Source: https://today.ucsd.edu/story/use-of-metformin-associated-with-exceptional-longevity-among-older-women