A National Institutes of Health funded study reported that semaglutide reduced several harmful effects of aging and extended lifespan in older, healthy mice. The work was carried out at the University of California, Berkeley, and no human trial of the aging question has been run.

Semaglutide is the active ingredient in GLP-1 drugs sold as Ozempic and Wegovy, widely used for obesity and type 2 diabetes. The interesting part of this paper is not appetite or blood sugar: the team set out to test whether the drug touches the aging process itself, and compared it head to head with calorie restriction, the most established lifespan intervention in laboratory animals.

What the mice showed

A team led by Danica Chen gave the drug to 20-month-old female mice for three months, meaning treatment started when aging was already well underway. Compared with untreated animals, the treated mice showed better muscle and cognitive function, and gene activity indicated reduced inflammation and less decline in the body's ability to repair and regenerate tissue.

The lifespan number is the one that will travel. In a separate group treated until death, median lifespan was nearly 100 days longer than in untreated mice.

Not just eating less

Because semaglutide suppresses appetite, the obvious objection is that the benefit is really calorie restriction wearing a different name. The researchers tested exactly that, running one group of 20-month-old female mice on the drug for five months against another on a 24% calorie-restricted diet matched to how much the treated animals were eating.

Most physiological measurements stayed stable in both groups, but the drug-treated mice improved beyond their starting levels in exploratory behavior, spatial memory and blood-sugar maintenance. Their metabolic rate also stayed largely unchanged, while metabolism slowed in the calorie-restricted animals.

Limitations

This is a mouse study, in female mice only, and the findings do not show that Ozempic, Wegovy or any other GLP-1 drug can extend human lifespan. Additional clinical research is needed to determine whether the effects translate to people, and the source cites a recent post-hoc analysis of the SLIM LIVER trial as one early example rather than an answer.

Where the research goes next

Chen said the differences point to the possibility that GLP-1 drugs tap into a biological pathway independent of calorie restriction, and called mapping that route an important direction for future work. Chen also said future clinical studies may investigate these drugs in healthy older adults, which is the point at which this stops being a mouse story.