Novo Nordisk and Eli Lilly report preliminary changes in molecular ageing clocks, but researchers warn the unreviewed findings do not demonstrate rejuvenation or longer lives.
Novo Nordisk and Eli Lilly have each offered fresh, early evidence that their blockbuster GLP-1 medicines may be linked to slower readings on molecular ageing clocks, but the findings stop well short of showing that the drugs reverse ageing or extend life. According to reporting by MIT Technology Review, the companies presented the work at the Aging Research and Drug Discovery meeting in Boston, with Novo’s analysis also posted as a preprint and Lilly’s data shown at the conference rather than in a peer-reviewed journal.
Novo’s analysis drew on blood-protein data from 10,052 participants in five placebo-controlled semaglutide trials, including the SELECT heart study and the FLOW kidney trial. The preprint said semaglutide was associated with a heart biological age roughly two to four years younger than placebo, while clocks for the kidney, brain, pancreas, lung and whole body showed reductions of about one to four years. The authors said those changes were not fully accounted for by weight loss, improved blood sugar or lower inflammation.
Lilly’s work on tirzepatide used epigenetic clocks, which estimate biological age from chemical changes on DNA. Kevin Duffin, Lilly’s vice-president for ageing research, told MIT Technology Review that the company’s clocks were showing a consistent pattern of reduced age, though he stressed that the effect was not remotely as large as a reversal of decades of ageing. Even so, the data remain preliminary, and ageing clocks are research tools rather than proof that someone will live longer, avoid dementia or escape chronic disease.
That distinction matters for patients and for anyone tempted by the latest anti-ageing headlines. Novo’s own researchers said their findings do not establish biological rejuvenation, and the post-hoc design of the analyses limits what can be concluded. Several Novo authors are company employees and shareholders, according to the preprint disclosures, while Harvard biologist Vadim Gladyshev helped with the molecular measurements, MIT Technology Review reported. Earlier independent work has pointed in a similar direction, including a University of California, San Diego-led trial in adults with HIV-associated lipohypertrophy that found semaglutide slowed several epigenetic clocks over 32 weeks, although that study was small and focused on a specific patient group.
For now, the practical message is unchanged: these medicines are approved for conditions such as type 2 diabetes, obesity and some related heart and kidney risks, not for longevity. Researchers at the Boston meeting also noted side effects, including muscle loss, and not everyone is persuaded that the evidence justifies use in healthy people. Steve Horvath of the University of California, Los Angeles, who is often credited with inventing ageing clocks, called the signal “a pretty strong effect”, but added that he had not yet seen enough evidence to support use in lean adults. He also said he was not ready to take the drugs himself. More definitive answers may come from federally backed trials in Texas, where ARPA-H has committed up to $38 million to studies of semaglutide, dapagliflozin and rapamycin in adults in their 60s, while another tirzepatide study is enrolling people aged 55 to 70.
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