Rapamycin (sirolimus)

synthetic

provenance:synthetic

first introduced:1999

regulatory status:off label

context:Rapamycin (sirolimus) is a macrolide compound originally isolated from a soil bacterium (*Streptomyces hygroscopicus*) and developed as a manufactured pharmaceutical, approved (branded Rapamune) as an immunosuppressant to prevent organ-transplant rejection. Animal studies reporting that its mTOR inhibition extends median lifespan in mice launched a wave of off-label longevity interest; Bryan Johnson's Blueprint protocol added it as an off-label component before later discontinuing it (American Council on Science and Health, 10 February 2025).

MECHANISM CLAIMED

Inhibits the mTOR (mechanistic target of rapamycin) signaling pathway, which is proposed to mimic effects of caloric restriction and slow biological aging by reducing cellular growth signaling and increasing autophagy.

MECHANISM ACTUAL

mTOR inhibition extends lifespan in several model organisms (yeast, worms, flies, mice) under controlled experimental conditions, but no randomized controlled trial has demonstrated a lifespan or healthspan benefit from off-label rapamycin use in healthy humans. As an approved immunosuppressant, it carries dose-dependent risks (infection susceptibility, impaired wound healing, metabolic effects) that are well characterized in its transplant-medicine use but not in the off-label longevity-dosing context. Bryan Johnson added rapamycin to his personal Blueprint protocol and subsequently discontinued it (American Council on Science and Health, 10 February 2025).

INTERVENTIONS USING IT

Blueprint (Project Blueprint)

EXTERNAL REFERENCES

Wikipedia

NOTES

Rapamycin is the archive’s clearest example, within the Blueprint case, of a component with genuine animal-model evidence (mouse-lifespan results from mTOR inhibition) still crossing into off-label human longevity use well ahead of any human randomized trial. Its regulatory status is exactly the “off_label” pattern common across this archive: approved for one indication (transplant-rejection prevention), used for another (anti-aging) on the strength of a mechanistic story and animal data, and in this case abandoned by its most prominent self-experimenting user.