Metformin improved heart stress tolerance in aging mice
In an experiment with 18-month-old male mice, six weeks of metformin helped preserve heart function after exposure to a stress-inducing drug.
Limit: The experiment measured drug-induced heart stress, not naturally occurring heart disease or lifespan
Edited by Boris Djordjevic · AgingResearch.News
In an animal experiment, researchers tested metformin in 18-month-old male C57BL/6 mice, a model of early heart aging. Mice received metformin in sweetened drinking water at 320 milligrams per kilogram of body weight, or sweetened water alone, for six weeks. After two weeks, they received isoproterenol, a drug used to induce heart stress, at 100 milligrams per kilogram by daily injection for five days. Metformin continued during exposure and recovery.
Isoproterenol impaired heart function compared with saline injections. After this stress, metformin improved heart performance and mitochondrial function compared with sweetened-water controls. Mitochondria are cells’ energy-producing structures. Metformin also reduced stress in the endoplasmic reticulum, the cell compartment that helps process proteins. Researchers monitored heart function weekly and collected hearts four weeks after the injections ended.
Why it matters
Heart aging begins before obvious dysfunction appears. The study explored whether this earlier period offers an opportunity to protect the heart against added stress.
Caveats
The experiment tested resistance to drug-induced heart stress, not lifespan or naturally occurring heart disease. Results in male mice do not establish benefits in people.
- Metformin
- Endoplasmic reticulum
- ER unfolded protein response
- Oxidative phosphorylation
- Mitochondrion
- Mice
Metformin is part of Bryan Johnson's Blueprint and David Sinclair's daily regimen in Lifespan
The paper
Metformin improves cardiac stress tolerance and mitochondrial function during early aging
Virginia Commonwealth University
Experimental Gerontology, May 2, 2026, Open access
