The mTOR inhibitor that has anti-aging researchers paying very close attention. Originally an immunosuppressant, now studied for its remarkable effects on lifespan extension across every organism tested. The most promising longevity drug in clinical research.
Rapamycin is an mTOR inhibitor originally developed as an immunosuppressant, now studied off-label for longevity. It's taken weekly (1mg) to shift metabolism toward cellular maintenance and repair—the state associated with extended lifespan in all model organisms tested, from yeast to primates. Requires bloodwork monitoring (sirolimus levels, CBC, lipids).
| Parameter | Value |
|---|---|
| Standard Dose | 1 mg weekly |
| Frequency | Once per week (Monday typical) |
| Cycling Protocol | 12 weeks on / 4 weeks off |
| Target Sirolimus Level | 5–15 ng/mL (trough) |
| Baseline Labs | CBC, lipids, liver function, sirolimus level |
| Monitoring Interval | Every 12 weeks (bloodwork at trough) |
| Key Interaction | CYP3A4 substrate—many drug interactions |
Rapamycin inhibits mTOR (mechanistic target of rapamycin), the master regulator of cellular growth. By suppressing mTORC1, rapamycin shifts cells from anabolic growth mode into catabolic maintenance and repair—the cellular state associated with longevity across species.
Rapamycin (sirolimus) is poorly absorbed orally with highly variable bioavailability (~14%). It binds extensively to plasma proteins (92%) and distributes widely into tissues. The long half-life (62 hours) permits once-weekly dosing for longevity protocols. Critical: CYP3A4 interactions mean drug-drug interactions are common and require careful monitoring.
| Bioavailability | ~14% (oral) — highly variable |
| Tmax (time to peak) | 1–3 hours |
| Elimination half-life | 62 hours (long!) |
| Steady state | 5–7 days (multiple weekly doses reach plateau) |
| Volume of distribution | ~100 L (widely distributed into tissues) |
| Protein binding | ~92% — primarily FKBP12 binding essential for mechanism |
| Metabolism | Hepatic — CYP3A4 (primary) and P-glycoprotein substrate. Extensive first-pass metabolism. |
| Excretion | Fecal ~91% (biliary/fecal route). Minimal renal excretion. |
| Food effect | Consistent dosing schedule (with or without food) is critical. Variability in absorption compounds pharmacokinetic unpredictability. |
Longevity dosing differs radically from transplant dosing. Weekly pulsed dosing (3–6mg once weekly) targets intermittent mTOR inhibition to maximize lifespan benefits while minimizing chronic immunosuppression. Consistency matters—take every week on the same day at the same time.
Rapamycin is the most-studied longevity intervention in biology. Lifespan extension data spans yeast, worms, flies, fish, mice, and primate studies. In humans, immune function improvement and safety data from decades of transplant use support its use at much lower longevity doses.
At longevity doses (3–6mg weekly), side effects are minimal compared to transplant dosing (5+ mg daily). However, rapamycin does require monitoring. Effects below are incidence rates at weekly longevity dosing from clinical observations and trial data.
Rapamycin is a strong CYP3A4 substrate and a P-glycoprotein substrate. Interactions are COMMON and can be dangerous. Any CYP3A4 inhibitor or inducer dramatically changes rapamycin levels. Your physician MUST review your full medication list. Live vaccines are contraindicated.
Book a consultation with a licensed physician to discuss whether rapamycin is appropriate for your longevity protocol.