Semaglutide Extends Mouse Lifespan by 12% in Groundbreaking Study

A study published in Nature on September 2, 2026, found that semaglutide, a GLP-1 receptor agonist used for diabetes and obesity, extended the median lifespan of 20-month-old female mice by 12%—about 100 days—while improving muscle function, cognitive performance, and metabolic health, according to research led by UC Berkeley’s Dr. Danica Chen.

The findings, derived from experiments conducted at the University of California, Berkeley, and funded by the National Institutes of Health (NIH), suggest that semaglutide may slow biological aging through mechanisms beyond simple calorie restriction, though the study was limited to female mice and did not confirm effects in humans.

Semaglutide’s Lifespan Extension in Mice

In the study, 20-month-old female mice—equivalent to 60-year-old humans—received daily semaglutide injections for their remaining lifespans. The drug extended their median lifespan from 742 days to 834 days, a 12% increase, according to Smithsonian Magazine and Nature. This effect was observed despite the mice not being subjected to strict calorie restriction, suggesting semaglutide’s benefits may stem from unique biological pathways.

These differences point to the possibility that GLP-1 drugs tap into a biological pathway independent of calorie restriction, said Dr. Danica Chen, a professor of metabolic biology and nutrition at UC Berkeley, in Drugtargetreview and Nature. The study’s authors noted that while calorie restriction is known to extend lifespan, maintaining such diets is challenging for humans, making semaglutide a potential calorie-restriction mimetic.

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The research team compared semaglutide-treated mice to those on a 24% calorie-restricted diet. Both groups showed similar improvements in lifespan and physical performance, but semaglutide-treated mice outperformed their counterparts in cognitive tests, such as spatial memory and exploratory behavior, as reported by Smithsonian Magazine and Drugtargetreview.

Mechanisms Behind the Effects

Gene expression analysis revealed that semaglutide reduced inflammation, improved regenerative capacity, and mitigated age-related declines in mitochondrial function. The drug also enhanced glucose tolerance and metabolic stability, according to Drugtargetreview and medindia.net. These findings align with earlier research suggesting GLP-1 agonists may target aging at the cellular level, not just treat symptoms of age-related diseases.

Photo: Smithsonian Magazine

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Most chronic diseases are deeply rooted in the ageing process. If GLP-1 agonists do indeed slow it down, then a wide range of clinical benefits is exactly what you’d expect to see, said Dr. Rafael de Cabo, a senior investigator at the NIH’s National Institute on Aging, in Drugtargetreview. The study’s authors emphasized that while the results are promising, they do not yet prove semaglutide’s effects in humans.

The research also highlighted differences in metabolic responses. While calorie-restricted mice experienced a drop in metabolic rate, semaglutide-treated mice maintained stable metabolism, suggesting the drug may influence aging through distinct physiological mechanisms, as noted in Nature and medindia.net.

Limitations and Future Research

Despite the encouraging results, the study was limited to female mice, raising questions about whether semaglutide would have similar effects in males.

Photo: Nature

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Additionally, concerns about muscle loss associated with GLP-1 drugs remain. The study did not address whether semaglutide could exacerbate age-related muscle decline, a critical consideration for human applications.

Future research will need to explore semaglutide’s effects in male mice and assess long-term safety in humans. Still, more testing in mice is needed, especially because the study involved only female animals.

Human trials are still in the early stages, and regulatory agencies have not yet approved semaglutide for longevity purposes. However, the findings have reignited interest in GLP-1 drugs as potential anti-aging therapies. Uncovering this potential route and the benefits that may specifically stem from it is an important direction for future research into the development of longevity-enhancing interventions, Chen said in Drugtargetreview and Nature.