Rapamycin
Sirolimus — mTOR Inhibitor & Longevity Drug
What is Rapamycin?
Rapamycin (Sirolimus) is an FDA-approved immunosuppressant that has emerged as the most studied pharmacological longevity intervention. It inhibits mTOR (mechanistic target of rapamycin) — a master regulator of cellular growth, metabolism, and aging. In animal studies, rapamycin consistently extends lifespan across multiple species. Human longevity trials are underway and the compound is increasingly used off-label by longevity-focused physicians.
Rapamycin binds to FKBP12, forming a complex that inhibits mTORC1 — the nutrient-sensing kinase that drives cellular growth and inhibits autophagy. By periodically inhibiting mTOR, rapamycin mimics some effects of caloric restriction: increased autophagy (cellular cleanup), improved mitochondrial function, reduced cellular senescence, and extended cellular replicative lifespan. Pulse dosing (once weekly) is used to achieve longevity benefits while minimizing immunosuppression.
Research Evidence
Rapamycin consistently extends lifespan in multiple organisms including yeast, worms, flies, and mice — with 10-25% lifespan extension in mammals even when started late in life. The most robust pharmacological longevity data in model organisms.
A randomized trial of low-dose rapamycin in older adults showed improved vaccine response (a marker of immune aging reversal) without significant side effects at low doses.
Ongoing human trials (PEARL, FAME) showing improvements in physical function, immune aging, and metabolic markers in older adults on low-dose pulse rapamycin.
Evidence grades: Gold = RCT human data · Silver = consistent animal/human data · Bronze = limited or preliminary
Dosing Protocols
Reconstitution / Preparation
This compound does not require reconstitution — it is available as an oral or pre-mixed formulation.
Frequently Asked Questions
Is rapamycin safe for longevity use?
At the low pulse doses used for longevity (1-6mg weekly), the side effect profile appears favorable in preliminary human trials. The main concerns are glucose elevation, lipid changes, and potential wound healing impairment. The immunosuppression is much less pronounced than at transplant doses. Leading longevity researchers including Peter Attia and David Sinclair discuss rapamycin as one of the most evidence-backed longevity interventions — though they note it requires medical supervision.
Does rapamycin affect muscle growth?
Potentially yes. mTOR is also required for muscle protein synthesis — sustained mTOR inhibition can impair muscle growth. This is why longevity protocols use pulse dosing (once weekly) rather than daily dosing: the weekly gap allows mTOR to drive protein synthesis most of the week while achieving the longevity effects during the inhibited phase.
References
- [1]Harrison DE, Strong R, Sharp ZD, et al. Rapamycin fed late in life extends lifespan in genetically heterogeneous mice. Nature. 2009;460(7253):392-395.
- [2]Mannick JB, Del Giudice G, Lattanzi M, et al. mTOR inhibition improves immune function in the elderly. Sci Transl Med. 2014;6(268):268ra179.
This profile was prepared using AI-assisted research synthesis. Citations are provided where applicable — verify with primary sources before clinical application.
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