 Rapamycin is not approved for pain or anti-aging, though doctors can prescribe it off-label. Kaeberlein has surveyed about 300 people who take low doses, and many report benefits. But anecdotes are no replacement for science, and that's where the dentist at the University of Washington comes in. Dr. Jonathan Ahn has FDA approval to test rapamycin in patients with gum disease, a common condition that tends to accelerate with age.