Really didn't expect this. Apparently this medication derived from an herb, known since ancient days to help with diabetes symptoms, has an effect which improves quality and quantity of life. Pretty safe, too, minimal side effects for most people. A Google search of this life-extending aspect of Metformin turns up less hits than expected, so it's nice to have this article from Wired floating around out there.
https://www.wired.com/story/this-pill-promises-to-extend-life-for-a-nickel-a-pop/
And also there is a related TEDx video from this guy: https://www.youtube.com/watch?v=TsA4SHhUzt4
Nah nevermind. Just watched it, and the video isn't as useful as the article.