It is safe enough to be sold OTC, and there are some research which connects with life extension effects. The real problem is that we don’t have human tests of its effects on longevity, despite its widespread use. The first study like this will be TAME, which will explore life extension properties of metformin. There are several reasons why such studies are difficult to perform. Firstly, they are costly, but known safe things are non-patentable. Secondly, they need to be very long., and long human studies are especially costly.
It is safe enough to be sold OTC, and there are some research which connects with life extension effects. The real problem is that we don’t have human tests of its effects on longevity, despite its widespread use. The first study like this will be TAME, which will explore life extension properties of metformin. There are several reasons why such studies are difficult to perform. Firstly, they are costly, but known safe things are non-patentable. Secondly, they need to be very long., and long human studies are especially costly.