TL;DR
Getting old means losing muscle and wearing out joints, and medicine has mostly treated both as one-way streets. A Stanford discovery suggests they might not be. An enzyme called 15-PGDH builds up as bodies age, and in old mice, blocking it regrew muscle and real knee cartilage. A once-a-day pill that blocks it has already proved safe in older adults, and its maker is preparing a 200-person trial to see whether it rebuilds muscle in people with age-related muscle loss. The scientist behind the idea calls it "a GLP-1 for muscle and cartilage." If it works, frailty could become something doctors treat rather than watch. But nobody has shown it makes a single person stronger, and that trial has just slipped to 2027.
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 "Epirium's MF-300 Phase 2b begins enrolling by 2027"; and every source.