Rapamycin (sirolimus)

Rapamycin (sirolimus) is a macrolide mTORC1 inhibitor approved as an immunosuppressant to prevent kidney transplant rejection and to treat lymphangioleiomyomatosis. By inhibiting mTORC1, it slows protein synthesis, enhances autophagy, and extends lifespan in yeast, worms, flies, and mice across multiple labs. Off-label use for human longevity remains investigational; clinical trials are evaluating intermittent low-dose protocols, but efficacy and long-term safety in healthy adults are unproven.