TL;DR
For nearly a decade, the boldest idea in medicine had a cheap, ordinary face: metformin, a diabetes pill taken by millions, tested not against one disease but against aging itself. The trial meant to prove it, TAME, was launched in 2017 and has produced no results, and its organizer says a federal agency now handles it. Meanwhile, two scientific reviews this summer and fall found that no drug, metformin included, has been proven to slow human aging broadly. That sounds like bad news, and for metformin it is. But the larger project is moving: the FDA has started describing what a drug would have to show to be approved for aging, and a federal program is paying for the measuring tools such a trial would need. The first anti-aging approval, if it comes, now has a rough shape. It just may not be metformin.
Below the line, for paid subscribers: The full story: where it stands, how we got here and what's dated next; our Odds board on 5 milestones, starting with "The FDA names aging and longevity in its regulatory-science priorities by 2027"; our labeled speculation on what it adds up to; and every source.