After 60 Years, Scientists Uncover Unexpected Brain Effects of Popular Diabetes Drug Metformin

Researchers at Baylor College of Medicine found that metformin can lower blood sugar by acting in the brain’s ventromedial hypothalamus, not just in the liver or gut.

The drug suppresses Rap1 and activates SF1 neurons in this region; in mouse studies, metformin stopped working when Rap1 was absent there.

Even tiny brain doses of metformin reduced glucose levels, reinforcing the brain circuit’s role in diabetes control.

The study highlights a previously underappreciated brain target that could enable more precise blood sugar treatments.