Semaglutide slows signs of ageing and extends life in mice, study finds

A new study has found that semaglutide may have benefits beyond weight loss and blood sugar control. Researchers found that the drug slowed several signs of ageing and extended lifespan in older female mice.

In Short

• Researchers treated 20-month-old female mice and tracked changes for three months
• Food intake fell about 24 per cent, with body fat dropping
• Treated mice showed stronger coordination, endurance, movement and glucose control

A drug already widely known for its role in weight loss and diabetes treatment may have another possible benefit: slowing some effects of ageing. A new study published in Nature has found that semaglutide, a GLP-1 receptor-activating medicine, improved several measures of physical health and extended lifespan in older female mice.

The findings are important because researchers have been looking for ways to reproduce some of the benefits linked with calorie restriction without requiring people to maintain a severely restricted diet for long periods. In the study, semaglutide appeared to produce several biological changes similar to those seen with calorie restriction, while also showing some additional benefits.

However, there is an important limitation. The study was conducted in mice, not humans. Researchers said that whether semaglutide can actually slow ageing or extend lifespan in people will need to be tested through long term clinical studies.

WHAT THE STUDY FOUND

Researchers treated 20-month-old female C57BL/6 mice with semaglutide. One group received the drug for the rest of their lives, while another group received control treatment. A separate group of mice was studied for three months to understand changes in physical function, metabolism and ageing-related processes.

The researchers found that semaglutide reduced food intake by about 24 per cent. The mice receiving the drug also lost body weight, with much of the weight loss coming from body fat. At the same time, the proportion of lean mass increased.

One of the most striking findings involved lifespan. The median lifespan was 742 days in the control group compared with 834 days among mice treated with semaglutide. Researchers said the findings suggested that semaglutide delayed age-related physical decline across several measures.

BETTER PHYSICAL AND COGNITIVE FUNCTION

The researchers also tested how the ageing mice performed physically and mentally.

Semaglutide-treated mice showed greater movement and exploratory behaviour. They performed better in tests measuring coordination, muscle function and endurance. The mice also showed better glucose control.

Memory-related tests produced another notable result. In a maze test, semaglutide-treated mice performed better on measures linked with spatial memory and learning. The study also found an increase in markers associated with the formation of new neurones in the hippocampus, a brain region involved in learning and memory.

DRUG APPEARED TO AFFECT AGEING PROCESSES

The researchers then examined several biological features commonly associated with ageing.

Semaglutide was linked with lower levels of ageing-related inflammation and cellular senescence. It also appeared to improve measures related to mitochondrial function, oxidative stress and protein quality control.

The study further found changes in blood-forming stem cells. Although some types of stem cells became less abundant, the researchers found signs suggesting that their regenerative capacity had improved. Semaglutide also increased markers of neural stem cell activity and neurogenesis in the hippocampus.

HOW SEMAGLUTIDE COMPARED WITH CALORIE RESTRICTION

Calorie restriction has previously been linked with slower ageing and longer lifespan in several animal studies. Researchers therefore directly compared semaglutide with calorie restriction in older mice.

Both approaches produced similar reductions in food intake, body weight and body fat. However, the way they worked was different. Calorie-restricted mice consumed their food quickly and then went through a longer period without eating. Mice receiving semaglutide ate more gradually, consistent with the appetite-suppressing effect of the drug.

The researchers found that semaglutide preserved several physical functions in a way that was comparable to calorie restriction. In some areas, including spatial memory and glucose control, semaglutide produced improvements beyond baseline measurements.

WHAT THIS MEANS FOR HUMANS

The findings add to growing research into the effects of GLP 1 medicines beyond weight management and diabetes. The researchers found that semaglutide influenced several biological pathways associated with ageing, including pathways involving metabolism, inflammation, cellular health and nutrient sensing.

Still, the findings should not be interpreted as proof that semaglutide is an anti-ageing drug for humans. The study involved older female mice of one strain, and the researchers themselves said that long term human studies are needed to determine whether GLP 1 receptor activation can change ageing or lifespan in people.

For now, the study offers a new area of research into how medicines that alter appetite and metabolism may also affect the biology of ageing. Whether those effects can translate from mice to humans remains an open question.

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