Skip to content
Back to glossary
Therapeutics

Metformin

Metformin is a cheap, decades-old diabetes pill (a biguanide). Doctors reach for it first in type 2 diabetes. It does two main things. It tells your liver to make less new sugar (it lowers hepatic gluconeogenesis), and it helps your cells respond to insulin. Under the hood, it blocks part of the mitochondria (complex I) and switches on an energy sensor called AMPK. In people with diabetes, observational studies hint at lower rates of death and cancer. That inspired the proposed TAME trial (Targeting Aging with Metformin). As of mid-2026 it still has not enrolled at scale. Taking metformin purely for longevity is still experimental. There is no proof it helps metabolically healthy people, and it may even blunt the gains you get from exercise.

Last reviewed:

This definition is educational and is not medical advice, a diagnosis, or treatment. Talk to a doctor about any health decisions. Read our full medical disclaimer

Sources

  1. Barzilai N, Crandall JP, Kritchevsky SB, Espeland MA. (2016). Metformin as a Tool to Target Aging. *Cell Metabolism*doi:10.1016/j.cmet.2016.05.011
  2. Bannister CA, Holden SE, Jenkins-Jones S et al.. (2014). Can people with type 2 diabetes live longer than those without? A comparison of mortality in people initiated with metformin or sulphonylurea monotherapy and matched, non-diabetic controls. *Diabetes, Obesity and Metabolism*doi:10.1111/dom.12354

Related studies from the research library