Sirolimus stays in your body for a long time—about 2.5 days—so even if you take it just once a week, it might still be active when you work out again.

Taking a weekly low dose of a drug called rapamycin while doing a 13-week home exercise program might help older adults (65–85 years old) get stronger legs — but we’re not totally sure how much it helps because the study was small and short.

In older adults who don't move much, taking a weekly rapamycin pill might slightly weaken the benefits of a 13-week home exercise program on leg strength and mobility, according to some detailed number crunching—even though the main results weren't clear-cut.