The drug rapamycin is commonly used to suppress the immune system in transplant patients, but scientists have found that it may also have anti-aging properties. The drug has "gained a large following thanks to longevity researchers and celebrity doctors who, citing animal studies, contend that [it] could be a game changer in the quest to fend off age-related diseases," said The Washington Post.
Rapamycin is a molecule "produced by soil bacteria on the extremely remote Easter Island located in the South Pacific, and was initially used for its antifungal properties," said the Daily Mail. It was later found to have immunosuppressant properties.
The drug has not been officially approved by the Food and Drug Administration as a tool to combat aging in humans. "The agency doesn't consider aging to be a disease, and rapamycin's generic status means there's little financial incentive to run expensive clinical trials to test it on age-related afflictions," said the Post.
This has not stopped biohackers, or people who are looking to expand their lifespan. Rapamycin has shown promise in reducing aging in mice, dogs and worms. Some people have been prescribed the treatment for this purpose, but "anecdotes are no replacement for science," said NPR. "To figure out the risks and benefits of a drug, research is needed."
Doctors also warn that "no one knows what the optimal dose might be for humans," the Post said, "and taking certain quantities of rapamycin can lead to reproductive harm and insulin resistance, as well as making the body more susceptible to infection." | 
