Semaglutide is best known as a GLP-1 medicine used to treat diabetes and obesity, but researchers are beginning to investigate whether its biological effects extend beyond weight management.
In an NIH-funded experiment involving older female mice, semaglutide treatment was associated with improvements across several measures of health.
Researchers reported improvements in areas including muscle function, cognition, balance and physical endurance. Most strikingly, animals that continued receiving semaglutide until death had a median lifespan nearly 100 days longer than untreated mice.
Researchers also compared the effects with calorie restriction, a well-established experimental method of extending lifespan in several animal species.
The comparison suggested that semaglutide’s effects might not simply result from animals consuming fewer calories. Instead, GLP-1 signaling may influence biological systems involved in ageing through several mechanisms.
That possibility is scientifically interesting because GLP-1 receptors and related metabolic pathways interact with numerous organs, including the brain.
However, the most important limitation is straightforward: mice are not humans.
Many interventions that appear to extend lifespan in laboratory animals do not produce the same result in people. The study therefore does not establish that taking semaglutide will make humans live longer, nor does it justify using the medicine specifically as an anti-ageing treatment.
Instead, the findings provide researchers with another clue about the relationship between metabolism and ageing. Future studies can investigate which biological pathways produced the effects and whether any of them are relevant to healthy ageing in humans.
