It’s not exactly clear just how metformin affects aging, but researchers think it acts on several different hallmarks of aging—changes at the cellular, chromosomal and molecular levels which accumulate over time. These transformations are what can lead to onset of conditions like heart disease, diabetes, some cancers, or dementia, often known as “diseases of aging.” 

Many studies show that metformin targets these age-related cell changes. The result: Not only does it help control type 2 diabetes, but over time, people with diabetes taking the drug had lower death rates, better health, and longer lives compared with both diabetic and non-diabetics not taking metformin.

Metformin also has anti-inflammatory effects, which may contribute to its ability to slow aging. Since chronic inflammation is one hallmark of aging and age-related diseases, reducing inflammation can improve health and life span.

“It takes an old cell or an old organ and fixes a lot of things. And it has a domino effect; if you target one hallmark, it will affect the others.” says Dr. Nir Barzilai, director of the Einstein Institute for Aging Research and a professor of medicine and genetics at Albert Einstein College of Medicine in New York.

Plus, metformin’s been around for 60 years and is generally safe for most people, according to Steven Austad, distinguished professor and chair in Healthy Aging Research at the University of Alabama at Birmingham and senior scientific director of the American Federation for Aging Research.

Why treat aging

After about age 60, many of us start to accumulate age-related diseases like heart disease, diabetes, many forms of cancer, and dementia. Additionally, as people age, they’re more likely to have several conditions at the same time. Researchers believe it’s the biology of aging that drives these diseases, so preventing them means slowing down the aging process itself. The goal is to help people not only live longer, but live with less disease, resulting in greater health span—the period of time spent free from disabling disease.

However, the FDA does not recognize aging as a preventable condition. So, each medical problem is treated separately. But by targeting aging itself, and mitigating changes at the cellular level, we could treat or prevent all of these conditions together, which would mark a huge shift in how we approach age-related diseases, according to Barzilai.

Metformin is derived from Galega officinalis, also known as goat’s rue, a traditional herbal medicine in Europe, which had been used for centuries to treat numerous ailments, including digestive health and diabetes-like issues. Galega contains guanidine, which, in 1918, was shown to lower blood glucose. Metformin, a synthesized version of guanidine, was first used as a diabetes treatment in France in the 1950s and was finally approved in the United States in 1995.

More than 150 million people worldwide currently use the drug to manage their type 2 diabetes. Metformin is also taken “off-label” for conditions including prediabetes, polycystic ovary syndrome, and weight gain from other medications, as well as for its apparent anti-aging benefits, although some in the scientific community remain unconvinced.

Metformin side effects and risks

“Metformin has as good a safety profile as virtually any drug you can find,” Austad says.

He points out that any side effects from metformin are generally mild, and usually consist of gastrointestinal upset and vitamin B-12 deficiency.

People under age 50 who work out specifically to build muscle may not achieve their desired results while taking metformin.

“But for people that are beginning to experience the maladies of aging, there’s a lot of observational evidence that it’s very good for you.”

Observational studies are not as rigorous as clinical trials, which is something Barzilai, one of the leading experts on metformin’s effects on aging, is working to correct. He’s finalizing funding for the Targeting Aging with Metformin (TAME) trial, which will track 3,000 adults 65 to 80, who will take metformin for six years. These trials will test whether those taking metformin experience delayed onset or progression of age-related chronic diseases, according to the American Federation for Aging Research, which is helping to fund the study.

The goal for Barzilai is proving his hypothesis (and convincing the FDA) that aging can indeed be treated as a disease—and that metformin is the tool to do so.

Should you take metformin for longevity?

Metformin is not currently approved as an anti-aging treatment. While some doctors may be willing to prescribe it off-label, it’s best to speak with your health care provider about the risks versus any potential benefits.