(NPR) – Rapamycin was first approved by the FDA for use in transplant patients in the late 1990s. At high doses it suppresses the immune system. At low doses, Kaeberlein says it seems to help tamp down inflammation. It works by inhibiting a signaling pathway in the body called mTOR — which seems to be a key regulator of lifespan and aging.

The drug is not approved for pain or anti-aging, but some physicians prescribe rapamycin off-label with the aim of fending off age-related conditions. Kaeberlein and his colleagues surveyed about 300 of these patients, who take low doses, and many report benefits. (Read More)