Metformin emerges as a promising candidate at the intersection of aging and longevity: Study
A new review was published in Volume 18 of Aging on August 10, 2026, titled “Metformin at the convergence of aging and longevity.”
The review was authored by Jarra Manneh, May Alasmar and Nady El Hajj from the College of Health and Life Sciences at Hamad Bin Khalifa University, Qatar Foundation, Doha, Qatar. Corresponding author Nady El Hajj is also affiliated with the College of Science and Engineering at Hamad Bin Khalifa University, Doha, Qatar.
Metformin has been used for decades as a first-line treatment for type 2 diabetes, but increasing interest in geroscience has raised a broader question: could this widely used metabolic drug also influence the biological processes that drive aging? The review brings together evidence from cellular studies, animal models, human observational research, and clinical trials examining how metformin interacts with multiple hallmarks of aging.
A central mechanism involves AMP-activated protein kinase (AMPK), a major cellular energy sensor. By inhibiting mitochondrial complex I and altering cellular energy balance, metformin can activate AMPK, triggering downstream effects that include suppression of mechanistic target of rapamycin (mTOR) signaling, increased autophagy and mitochondrial biogenesis, and reduced oxidative stress. Metformin also improves insulin sensitivity and reduces hepatic gluconeogenesis, connecting its established metabolic effects with nutrient-sensing pathways involved in aging biology.
The authors identify particularly strong evidence for metformin’s interactions with deregulated nutrient sensing, mitochondrial dysfunction, impaired macroautophagy, cellular senescence, and epigenetic alterations. Evidence also supports effects on chronic inflammation and dysbiosis, while associations with hallmarks such as telomere attrition and stem-cell exhaustion remain more indirect or emerging.
Epigenetic regulation represents another important pathway. Metformin has been reported to influence DNA methylation, histone modifications, and non-coding RNAs through mechanisms involving AMPK, SIRT1, and other regulatory proteins. Human studies have also reported associations between metformin use and reduced epigenetic age acceleration. However, the authors caution that changes in molecular aging markers do not yet establish that metformin slows biological aging or extends healthy lifespan in humans.
The gut microbiome may provide an additional link between metformin and systemic aging processes. Oral metformin reaches high concentrations in the gastrointestinal tract and has been associated with changes in microbial populations and short-chain fatty acid production. These microbial metabolites can influence intestinal integrity, inflammation, insulin sensitivity, AMPK activity, and epigenetic regulation, suggesting that some of metformin’s systemic effects may arise through interactions between host metabolism and the intestinal microbiota.
Evidence for longevity effects spans several experimental systems. Studies summarized in the review have reported lifespan extension in Caenorhabditis elegans and multiple mouse models, while research in male cynomolgus monkeys found reductions in biological-age markers across several tissues. Human observational studies have also linked metformin use with favorable survival and aging-related outcomes, although some prominent findings have subsequently failed to replicate and therefore require cautious interpretation.
This distinction is important because much of the human evidence comes from people with diabetes or other health conditions. Studies have also used widely differing endpoints—including mortality, cardiovascular disease, cancer, frailty, and biological-age markers—making it difficult to determine whether metformin broadly modifies aging or instead improves selected disease outcomes in particular populations.
Clinical trials have been designed to address these questions. The Targeting Aging with Metformin (TAME) initiative was designed to examine whether metformin could delay multiple age-related diseases in older adults without diabetes. The randomized MeMeMe trial, involving more than 1,400 people aged 50–79 with metabolic syndrome, found that metformin reduced the development of type 2 diabetes. However, no preventive effect was observed for cancer, cardiovascular disease, or mortality.
Safety is also an important consideration for any potential long-term gerotherapeutic use. Metformin is generally well tolerated, but prolonged treatment has been associated with vitamin B12 deficiency, while metformin-associated lactic acidosis is a rare but serious complication, particularly in people with impaired renal function or other predisposing conditions.
“By merging data from clinical, molecular and population level, metformin could be the wonder drug that redefines the limits of healthy aging.”
Despite its broad biological effects, major questions remain unresolved. The optimal dose, treatment duration, and age at initiation for potential geroprotective effects are unknown, as is whether benefits differ according to diabetes status, sex, body composition, or age. Most importantly, adequately powered randomized trials with clinically meaningful aging endpoints in non-diabetic populations remain limited.
Overall, the review positions metformin as a compelling candidate at the intersection of metabolic medicine and geroscience. Its effects on AMPK and mTOR signaling, mitochondrial function, autophagy, epigenetic regulation, cellular senescence, inflammation, and the gut microbiome provide several plausible biological pathways through which it could influence aging. However, stronger randomized clinical evidence will be needed to determine whether these molecular and metabolic effects translate into meaningful extensions of healthspan or delayed age-related disease in otherwise healthy people.
Reference:
Manneh J, Alasmar M, Hajj N. Metformin at the convergence of aging and longevity. Aging (Albany NY). 2026; 18:970-990. https://doi.org/10.18632/aging.206407
