Weight-loss drugs show signs of slowing biological aging, say drugmakers

Matt Honan (0:00)

Welcome to MIT Technology Review Narrated. My name is Matt Honan. I'm our Editor-in-Chief.

Every week, we'll bring you a fascinating, new, in-depth story from the leading edge of science and technology, covering topics like AI, biotech, climate, energy, robotics and more. Here's this week's story. I hope you enjoy it.

SPEAKER_2 (0:22)

Narrated by Noa. Listen to more of the best articles from the world's biggest publishers on the Noa app, or at newsoveraudio.com.

Jane Wing (0:32)

Antonio Regalado writes, Weight loss drugs show signs of slowing biological aging, say drug makers.

Popular weight loss drugs may do more than help people shed pounds. They may also melt away the years. Drug giants Eli Lilly and Novo Nordisk say patients taking their drugs age less quickly. According to readouts from Molecular Aging Clocks, such clocks assess a person's biological age by looking at changes to DNA that accumulate with time, or in newer versions by tracking levels of key proteins. Both companies found that overweight or diabetic patients taking the drugs, called GLP-1s, had reduced biological age compared to those taking a placebo, although the difference varied widely, depending on which type of clock was used and what organ was tested. Overall, the difference was around 2 to 3 years, according to Nicolai Rode, a global project leader at Novo, who says the company has been seeing improved biological age in old patients across trials and across different tissues.

The findings add to wide speculation among scientists that GLP-1 drugs, as they are known, are acting on basic causes of ageing, and might be a true longevity treatment. Two years is a pretty strong effect in my book, says Steve Horvath, a professor at the University of California, Los Angeles, who's credited with inventing ageing clocks. Horvath says the emerging data could provide evidence that these GLP-1 drugs are actually what is known as geroprotectors, medications that slow or possibly even reverse biologic ageing.

The companies shared their findings over the weekend during Ageing Research and Drug Discovery, a conference devoted to seeking scientific remedies for old age. While that quest has not yet produced any clear-cut success, some scientists now think Novo's drug samaglitide, sold under the names Ozempic and Wegovi, is coming close. In an unhealthy population, I do think it's an anti-ageing drug, says Vadim Gledishev, a Harvard biologist who assisted Novo with its molecular measurements. But in a healthy population, no one knows.

The drugs cause weight loss by stimulating a receptor, GLP-1, that tells your brain you're not hungry. Yet real-world studies have shown much wider benefit. The drugs improve kidney function, reduce blood pressure, and even sharply cut the overall chance of death. If the question is, can some agglutide reach several diseases relevant to health span and aging, we know we can say the answer is yes, said Alejandro Aguajo Orozco, a senior scientific director at Novo, the Danish drug giant, during the meeting. The next question to answer, he said, is whether such effects are accompanied by changes to molecular measures of biological aging. When you intervene with some agglutide, does it actually move the clocks in any direction? And the answer is yes. The company found that over time the drugs cause a wide slowdown in aging clocks, as much as four years in the case of a clock that looks at heart proteins. I think it's pretty clear that the organ age is shifting, said Aguajo Orozco.

The studies are also a huge boost for the science of aging clocks. Although these measures reflect a person's age, it's been uncertain if they are useful as true biomarkers. Now, clockmakers have evidence that their readouts show a drop in age when people take drugs with broad, well-demonstrated benefits. The clock people have been pushing for a decade to get this kind of study done, says Yuki G., a biologist who previously worked in the field and now runs a start-up, Reflector Bio. It's huge for them.

As part of its study, Novo took blood draws from 10,052 people, half on the drug and half on a placebo. Their blood, collected at the start of the study as well as months later, was then measured with proteomic clocks, which use levels of key proteins to predict a person's age and risk of dying. Scientists at Eli Lilly performed similar research on their GLP-1 drug, Tazepatide, using so-called epigenetic clocks that assess age by counting accumulated changes to DNA. Lilly's study was smaller, but also found that for the most part, molecular time moved more slowly for people on the drug. All the clocks are telling a consistent story that we're seeing a reduction in age. Kevin Duffin, Vice President for Aging Research at Lilly, said during the conference, It's not like we're going to reverse age by 30 years or something, but it's a significant reduction. The molecules have become the best selling drugs in the world, with Lilly's to Zepatide, sold as Manjaro for diabetes, and Zetbound for obesity, topping the list with more than $36 billion in revenue to the company in 2025