Rapamycin (sirolimus) is a macrolide mTOR inhibitor, not a peptide. It is FDA-approved as an immunosuppressant for renal transplant rejection prophylaxis and for lymphangioleiomyomatosis (LAM), and is used off-label at low intermittent doses for longevity. It is the most robustly validated pharmacological lifespan-extender in the NIA Interventions Testing Program, extending median and maximum lifespan in mice even when started in late life. Human longevity evidence remains thin: the PEARL trial (2024) established tolerability of weekly dosing in healthy adults but was not powered for aging outcomes.
Category: Anti-Aging / Autophagy. Evidence rating: B (meaningful human data).
Clinical status: FDA-approved (Rapamune) for renal transplant rejection prophylaxis and LAM. All longevity use is off-label and requires a prescription.
Rapamycin binds FKBP12, and the rapamycin-FKBP12 complex allosterically inhibits mTORC1, the nutrient- and growth-factor-sensing kinase complex that drives protein synthesis, ribosome biogenesis, and lipid synthesis while suppressing autophagy. Inhibiting mTORC1 shifts cells from a growth program…
Safety considerations: Immunosuppression is the defining risk. Chronic daily dosing measurably increases infection risk; weekly intermittent dosing is intended to avoid this but does not eliminate the concern; Impaired wound healing — a genuine practical issue. Rapamycin should generally be paused around elective surgery, and this interacts badly with any concurrent healing-peptide protocol; Stomatitis and mouth ulcers are the most common dose-limiting side effect at higher doses.
Reviewed by the PeptideAtlas Editorial Team.
| Molecular formula | C51H79NO13 |
|---|---|
| Molecular weight | ~914.2 g/mol |
| CAS number | 53123-88-9 |
| Half-life | ~62 hours |
| Bioavailability | ~14% oral (highly variable, food-dependent) |
| Production method | bioactive |
| Anti-doping status | not-listed |
| US regulatory status | FDA-approved prescription drug (Rapamune, sirolimus). Longevity use is off-label. Not a supplement and not legally sold as a research chemical for human use. |
Related peptides: Tat-Beclin 1.
No. It is a macrolide small molecule produced by Streptomyces hygroscopicus. It appears in this library because it is routinely discussed alongside longevity peptide protocols, not because it belongs to the same class.
Weekly dosing exploits the difference between mTORC1 and mTORC2 inhibition. mTORC1 (the target) is inhibited acutely; mTORC2 (responsible for much of the immunosuppression and glucose intolerance) requires sustained exposure. With a ~62 hour half-life, weekly dosing lets levels fall between doses.
No. PEARL was a 48-week safety and tolerability trial. It showed weekly low-dose rapamycin was tolerated in healthy adults. It was not designed or powered to demonstrate an effect on aging, disease incidence, or mortality.
This is a poor pairing on mechanism. Rapamycin impairs wound healing and suppresses the growth signalling that regenerative protocols are trying to stimulate. The two work against each other.