Rankings / Comparisons
Metformin vs Rapamycin (sirolimus)
Two off-label longevity heavyweights with very different evidence depths and risk profiles.
Reviewed by Read Off Label · How we grade
Score comparison
Metformin has the higher descriptive composite (B+, 7.2/10) compared with Rapamycin (sirolimus) (C, 5.0/10). The axes below show whether that difference comes from evidence, reported benefit, safety, or a combination.
B+ 7.2/10
aka Glucophage, Glumetza, Fortamet, Riomet
- Evidence
- Strong (in T2D); Moderate observationally (non-diabetics); Preclinical (pure anti-aging) (8/10)
- Benefit
- Varies (5/10)
- Risk
- Low-Med (GI side effects; B12 deficiency with chronic use; lactic acidosis rare; may blunt exercise adaptations) (7/10 safety)
- Legality
- Rx (off-label for longevity)
- Dose / route context
- 500-2000 mg/day PO; clinical titration commonly begins at 500 mg with meals
- Class
- Prescription
- Last reviewed
- Jul 1, 2026
Read Off Label grades Metformin as B+ (7.2/10) based on strong evidence, variable benefit magnitude, and a low-med-risk safety profile.
UKPDS showed 36% reduction in all-cause mortality in T2D.
Studied, labeled, or reported-use context: 500-2000 mg/day PO; clinical titration commonly begins at 500 mg with meals — Rx; not individualized guidance.
What it is
UKPDS showed 36% reduction in all-cause mortality in T2D. TAME trial ($75M, 3000 non-diabetic older adults) repeatedly delayed — FDA approved design but unfunded. 2019 Konopka data: may blunt exercise-induced mitochondrial adaptations.
Mechanism
Complex I mild inhibition → AMPK activation → mTOR inhibition; improved insulin sensitivity; possible gut microbiome effects; reduced hepatic gluconeogenesis
Full Metformin review →
- Evidence
- Moderate-Weak (human healthspan — PEARL 2025 missed primary); Strong (rodent lifespan — most replicated longevity intervention ever) (4.5/10)
- Benefit
- Med-High (projected from animal data) (6.5/10)
- Risk
- Med (immunosuppression, mouth sores, hyperlipidemia, insulin resistance, wound healing impairment) (5/10 safety)
- Legality
- Rx (off-label for longevity)
- Dose / route context
- 5-10 mg PO weekly (off-label longevity dosing); much higher for transplant
- Class
- Prescription
- Last reviewed
- Jun 8, 2026
Read Off Label grades Rapamycin (sirolimus) as C (5.0/10) based on moderate-weak evidence, med-high benefit magnitude, and a med-risk safety profile.
ITP: single most reproducible life-extending compound in mammals.
Studied, labeled, or reported-use context: 5-10 mg PO weekly (off-label longevity dosing); much higher for transplant — Rx; not individualized guidance.
What it is
ITP: single most reproducible life-extending compound in mammals. PEARL trial (Moel et al, Aging April 2025; n=114, 48 weeks, 5 or 10 mg weekly): MISSED primary endpoint of visceral adiposity reduction (η²=0.001, p=0.94) and most biomarkers unchanged. Secondary signals: lean tissue mass and self-reported pain improved in women on 10 mg; emotional well-being and general health improved at 5 mg. Adverse events similar to placebo — confirming safety at these doses. Most discussed longevity drug but human efficacy data remains underwhelming.
Mechanism
Binds FKBP12; inhibits mTORC1 — the central nutrient-sensing kinase complex; induces autophagy; reduces protein synthesis; intermittent dosing may spare mTORC2
Full Rapamycin (sirolimus) review →
Common questions
- How do the evidence profiles of Metformin and Rapamycin (sirolimus) compare?
- Metformin has the higher descriptive composite (B+, 7.2/10) compared with Rapamycin (sirolimus) (C, 5.0/10). The axes below show whether that difference comes from evidence, reported benefit, safety, or a combination.
- What's the difference between Metformin and Rapamycin (sirolimus)?
- Two off-label longevity heavyweights with very different evidence depths and risk profiles.
- Can you take Metformin and Rapamycin (sirolimus) together?
- The available evidence is use- and population-specific. Each page documents mechanism, studied or reported dose context, risks, and legal status; the database does not determine whether a combination is appropriate for an individual.
This is an independent synthesis of published research by a non-clinician.
The comparison reports composite and axis-level differences without selecting
an intervention for the reader. Relevance depends on indication, population,
dose, duration, and other context. See the full
disclaimer and methodology.