Can you take Metformin and Rapamycin (sirolimus) together?

Read Off Label doesn't make stack recommendations — see the disclaimer. Both compounds have individual mechanism, dose, and risk profiles documented on their respective pages; combining them is a clinical question that depends on the goal, indication, and other context.

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

Bottom line

On the composite score, Metformin (B+, 7.2/10) edges out Rapamycin (sirolimus) (C, 5.0/10) — but the right pick depends on the specific outcome you're optimising for.

Metformin

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: 500-2000 mg/day PO; titrate from 500 mg with meals
Class: Prescription
Last reviewed: Jun 8, 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.

Typical use: 500-2000 mg/day PO; titrate from 500 mg with meals — Rx.

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 →

Rapamycin (sirolimus)

C 5.0/10

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: 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.

Typical use: 5-10 mg PO weekly (off-label longevity dosing); much higher for transplant — Rx.

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

Which is better, Metformin or Rapamycin (sirolimus)?: On the composite score, Metformin (B+, 7.2/10) edges out Rapamycin (sirolimus) (C, 5.0/10) — but the right pick depends on the specific outcome you're optimising for.
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?: Read Off Label doesn't make stack recommendations — see the disclaimer. Both compounds have individual mechanism, dose, and risk profiles documented on their respective pages; combining them is a clinical question that depends on the goal, indication, and other context.

This is an independent synthesis of published research by a non-clinician. Comparison-page verdicts use the composite Read Off Label score as a tiebreaker, but the right pick for any given person depends on indication, context, and clinician input. See the full disclaimer and methodology.