Peter Attia welcomes David Sabatini and Matt Kaeberlein, experts on rapamycin and mTOR. They discuss the discovery of rapamycin, its potential benefits on lifespan, and the biology behind its effects. They also touch on the dosing of rapamycin in humans and reservations about prescribing it as a longevity drug. Topics include emergence of rapamycin as a geroprotective molecule, groundbreaking mouse study on lifespan extension, and the biochemistry of rapamycin and the mTOR protein complex.