Could GLP-1 Drugs Slow Aging? A New Trial Is Putting the Theory to the Test

Scientists are investigating whether the popular GLP-1 medications that are already reshaping the treatment of obesity and diabetes could have the potentially significant effect of slowing biological aging.

Researchers are beginning clinical trials aimed at determining whether drugs such as tirzepatide and semaglutide can influence some of the biological processes associated with getting older, according to a report from ABC News' "Good Morning America."

The research is still in its early stages, and there is currently no scientific evidence that healthy people should take GLP-1 medications to live longer. But preliminary findings have given scientists enough reason to investigate whether the drugs' effects extend beyond weight loss and blood sugar control.

One of the first clinical trials specifically examining the question is being led by researchers at the University of Texas Medical Branch in Galveston, Texas. The study will examine tirzepatide, the active ingredient in the weight-loss drug Zepbound.

"[We] ultimately hope that our research will show that we slow biologic aging by 10 to 15%," Dr. Thomas Blackwell, a professor of medicine at UTMB, told ABC News. "We think there's a lot of people taking GLP-1s. Wait till we prove that it also slows your aging process. Everybody's going to want to take a GLP-1," Blackwell added.

The UTMB trial will enroll adults between the ages of 55 and 70 who qualify for weight-loss treatment. Rather than simply measuring whether participants lose weight, researchers plan to look at a range of indicators connected to aging.

Those include biological age markers and inflammation levels, as well as changes in cognitive function, physical strength and mobility. The goal is to determine whether tirzepatide could affect the underlying biological processes associated with aging rather than merely treating individual health conditions.

Interest in the possibility has been fueled in part by earlier research involving semaglutide, the active ingredient in Ozempic and Wegovy. Researchers from the UC San Diego School of Medicine and Case Western Reserve University analyzed blood from 84 adults with HIV who also had abnormal accumulation of body fat.

After participants received semaglutide for 32 weeks, researchers found changes consistent with slower biological aging according to several DNA-based measurements known as "aging clocks." The findings were not proof that semaglutide makes people live longer, and researchers cautioned that the study had significant limitations.

"This was really kind of the first look to say, hey, in this scenario, which has a lot of limitations, there essentially was a signal here that warranted future study," Dr. Michael Corley, an associate professor of medicine at UC San Diego, told ABC News.

Biological aging is different from chronological aging, which is simply the number of years a person has been alive. Scientists studying longevity increasingly examine molecular and physiological changes that may provide clues about how quickly the body is aging.

That distinction is particularly important when assessing GLP-1 medications. Losing excess weight can itself improve several measures of health, making it necessary for researchers to determine whether any apparent anti-aging effect comes directly from the medication, from weight loss and improved metabolic health, or from a combination of factors.

Scientists will also need much larger and longer studies before determining whether changes in biological aging markers translate into people remaining healthier for longer or actually extending lifespan. "In terms of living longer, these are kind of the studies that need to be conducted further in terms of looking at rigorous clinical trial designs with a particular aging focus," Corley said.