Main conclusion
In a randomized trial involving people with prediabetes, metformin increased relative leukocyte telomere length, telomerase activity, and SIRT1 expression. The finding is biologically interesting but does not demonstrate rejuvenation or longer life.
What the study did
The trial enrolled 127 adults aged 30–60 from North India; 112 completed 24 weeks. Participants received metformin 500 mg twice daily or placebo, with lifestyle counseling in both groups. Relative leukocyte telomere length increased by 29.6% with metformin and 4.4% with placebo. Telomerase activity and SIRT1 expression also increased.
Key limitations
Telomeres were measured by qPCR in leukocytes. A short-term change may reflect shifts in cell populations, measurement variability, or transient telomerase activation. The trial did not assess frailty, age-related disease, cancer, mortality, or durability. Participants had prediabetes; they were not healthy longevity users.
What can be said to patients
Metformin remains a medication for defined metabolic indications. This RCT supports further study of aging biomarkers, not self-prescribing the drug for rejuvenation.
Source
Mechanisms of Ageing and Development, 2026. DOI: https://doi.org/10.1016/j.mad.2026.112241
PubMed: https://pubmed.ncbi.nlm.nih.gov/42692117/
Educational material; it does not replace individual medical advice.