I don't think it's primary effect on lifespan is through glucose regulation. There are other diabetes medications that don't have this same effect. Also see

I don't think it's primary effect on lifespan is through glucose regulation. There are other diabetes medications that don't have this same effect. Also see https://www.gwern.net/Longevity#metformin https://www.gwern.net/Longevity#metformin for more info.