When rats have a heart attack, giving them metformin (a common diabetes drug) seems to help lower harmful stress in their heart tissue, compared to rats that don’t get the drug.

When rats have a heart attack and are given metformin, their blood shows changes in certain natural chemicals—some go down, like arginine and tryptophan, while others, like azelaic acid, go up.

When rats have a heart attack and are given metformin, their hearts show less thickening and scarring, even though the size of the damage and overall heart function don’t get better or worse.

In rats that had a heart attack, taking metformin didn’t make the heart damage smaller or improve how well the heart pumped, but it did help reduce some of the scarring and thickening in the heart muscle.

In diabetic rats and mice, a common diabetes drug called metformin helps protect the heart after a heart attack by making the body use insulin better and lowering harmful stress in the cells.

When rats have a heart attack and are given a common diabetes drug called metformin, their gut bacteria become more varied and diverse than in rats that didn’t get the drug.