From T. C. Gibian:

Re: Already-approved drug tied to longer, healthy life in mice (May 25, 2013): Rapamycin’s effect on the mTOR pathway is well documented. The trouble with this drug is that it has proven somewhat toxic and requires very careful administration. Another well tested drug with the same effect but none of the detrimental side effects is Metformin, also known as Glucophage. This medication is used to reduce blood sugar, but has attested beneficial effects on the mTOR pathway and has demonstrated to reduce the incidence not only of diabetes, but also some types of cancer. This information can be verified by articles in Wikipedia and in Scientific American.