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Longevity

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mTOR inhibitor

Rapamycin

Also known as: Sirolimus, Rapamune, Macrocyclic lactone — 31-carbon macrolide

Approved immunosuppressant for transplant; the canonical mTOR inhibitor. Off-label longevity dosing (5–8 mg weekly) is widely community-practiced; PEARL Phase 2 (2024) is the largest healthy-adult RCT and was equivocal.

Reviewed 2026-05-05

What it does

Rapamycin (sirolimus, Rapamune) is a small-molecule macrocyclic lactone — not a peptide — that inhibits mTORC1 signaling. It is included in this 'peptide companion' library for the same reason as NAD+ and glutathione: longevity-clinic and self-experimenter communities routinely stack it with peptide regimens, and competitor apps quietly include it without disclosing it isn't a peptide. Its clinical pedigree is excellent for its approved use (kidney-transplant rejection prophylaxis since 1999) and for tuberous sclerosis complex. The longevity application — once-weekly dosing of 5–8 mg in healthy adults to mimic the lifespan-extension findings in mice — is community practice rather than approved use. The PEARL Phase 2 trial (Mannick / AgelessRx, 2024-2025 readouts) is the largest healthy-adult RCT on intermittent rapamycin and gave equivocal results.

Used for

Dose

Starting
1,000 mcg · once weekly (longevity off-label) or once daily (transplant)
Common
4,500 mcg · once weekly (longevity off-label) or once daily (transplant)
Upper
8,000 mcg · once weekly (longevity off-label) or once daily (transplant)
When
MorningWeekly dosing for longevity protocols (PEARL-style). Morning with food. Pick a consistent day + time and stick to it for adherence + tracking. Watch GI tolerance during the first few hours post-dose.
Site
oral

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⚠ Caution

  • Active infection (rapamycin is immunosuppressive, even at intermittent doses)
  • Active malignancy where the immune system is part of tumor surveillance
  • Pregnancy and breastfeeding (teratogenic risk)
  • Major surgery within ~2 weeks (impaired wound healing — a real, recurring side effect)
  • Uncontrolled hypercholesterolemia or hypertriglyceridemia (rapamycin worsens both)
  • Severe hepatic impairment
  • Concurrent use with strong CYP3A4 inhibitors / inducers without dose adjustment
  • Live vaccines (efficacy may be reduced; some live vaccines are contraindicated)

Your stack

Track this peptide in your protocol — dose, schedule, vials on hand, refill projection. Stays in your browser; no account needed.

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Use this peptide

Featured in protocols
  • LongevityPhase 2 — mTOR pulse (rapamycin weekly)
Reconstitution & storage

Oral tablet or oral solution — no reconstitution. Generic sirolimus is widely available through pharmacy channels with a prescription.

Storage. Tablets: room temperature per label. Solution: refrigerate 2–8 °C; once opened, follow label timing.

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Monitoring & questions

Reported side effects
  • Oral aphthous ulcers / mouth sores (the most common dose-limiting side effect of intermittent dosing)
  • Impaired wound healing (clinically meaningful; users typically pause before/after surgery or dental work)
  • Hyperlipidemia — elevated LDL and triglycerides (more pronounced with daily than weekly dosing)
  • Hyperglycemia / mild insulin resistance
  • Increased infection risk — herpes reactivation, sinusitis, UTI
  • Edema, including peripheral and pulmonary
  • Thrombocytopenia, anemia, neutropenia (cytopenias)
  • Proteinuria
  • Acneiform rash
  • Pneumonitis (rare, can be life-threatening; requires immediate evaluation)

Reference

How it works

Binds FKBP12, and the rapamycin–FKBP12 complex binds and inhibits mTORC1 (mechanistic target of rapamycin complex 1). mTORC1 is a master integrator of nutrient, growth-factor, and energy signaling — inhibiting it shifts cells from anabolic/growth modes toward autophagy and stress resistance. Chronic / continuous dosing also affects mTORC2 (insulin-signaling axis), which underlies several of the metabolic side effects (hyperglycemia, dyslipidemia). Intermittent (weekly) low-dose schedules are designed to preferentially hit mTORC1 while sparing mTORC2.

EvidenceTier 1 — Human RCT

Tiers are per indication. The same molecule can be Tier 1 for one use and Tier 4 for another — the tier reflects published literature, not community framing.

Kidney transplant rejection prophylaxis

Tier 1high confidence

FDA-approved since 1999 (Rapamune). Multiple Phase 3 trials demonstrated efficacy as part of immunosuppression regimens. This is the foundational clinical evidence base.

Tuberous sclerosis complex (subependymal giant cell astrocytoma, lymphangioleiomyomatosis)

Tier 1high confidence

FDA-approved for these TSC manifestations based on clinical evidence in subgroups; everolimus (close analog) shares the indication.

No primary citations are anchored to this indication — the tier reflects the absence of usable literature, not a missing reference.

Healthy human longevity / 'lifespan extension' off-label

Tier 3high confidence

Mouse Interventions Testing Program established lifespan extension in multiple genetic backgrounds — the most reproducible longevity intervention in rodents. PEARL Phase 2 RCT (n≈122) in healthy adults reported some functional improvements but mixed primary outcomes. Tier 3 reflects strong preclinical + emerging but underpowered human RCT evidence.

Immune-system rejuvenation in older adults

Tier 3medium confidence

Mannick 2014 and subsequent work showed mTOR inhibitors (RAD001/everolimus and rapamycin) can improve influenza-vaccine responses in older adults — an immune-rejuvenation signal. Tier 3 reflects translational human work that has not converted into approved indication.

General anti-aging in healthy adults

Tier 3high confidence

Mechanistically the strongest case in this library for any small molecule. PEARL provides the first dedicated healthy-adult RCT data. The story is interesting; the data is not yet definitive.

Citations (3)
  1. [1]
    Efficacy of sirolimus compared with azathioprine for reduction of acute renal allograft rejection: a randomised multicentre study
    Kahan BD · Lancet · 2000 · PMID 10872008
    Foundational Phase 3 transplant trial — anchor for the FDA-approved indication.
    View source
  2. [2]
    mTOR inhibition improves immune function in the elderly
    Mannick JB, Del Giudice G, Lattanzi M, et al. · Science Translational Medicine · 2014 · PMID 25540326
    Translational evidence that mTOR inhibition improves vaccine response in older adults — anchor for immune-rejuvenation indication.
    View source
  3. [3]
    PEARL: Participatory Evaluation of Aging with Rapamycin for Longevity (Phase 2 RCT readouts, 2024-2025)
    AgelessRx / Mannick JB et al. · Aging Cell / preprint readouts · 2024
    Largest healthy-adult RCT of intermittent rapamycin to date; mixed-positive readouts. Anchor for Tier 3 longevity indication.
    View source