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

Weight-loss drugs, including Eli Lilly's tirzepatide and Novo Nordisk's semaglutide, may also slow down biological aging, according to recent findings from molecular "aging clocks." These clocks gauge a person's biological age by examining DNA changes over time, or by tracking specific protein levels. Both companies observed that overweight or diabetic patients taking their drugs experienced reduced biological age compared to those on a placebo, with the difference averaging around "two to three years."

This effect is significantly stronger than previously thought, with Novo Nordisk's Nikolaj Roed noting improvements in patients across various tissues and trials. Steve Horvath, a UCLA professor and aging clock inventor, considered the two-year effect "pretty strong." The companies presented these findings at the Aging Research & Drug Discovery conference, which focuses on finding scientific solutions for aging.

While the drugs primarily function by stimulating the GLP-1 receptor to reduce hunger, real-world studies have revealed broader health benefits such as improved kidney function, reduced blood pressure, and lower mortality rates. Novo Nordisk's semaglutide (Ozempic and Wegovy) and Eli Lilly's tirzepatide have become best-selling drugs, with Lilly's product generating over $36 billion in revenue last year.

However, experts caution that despite the drugs' benefits, they may have side effects like muscle loss and are not suitable for everyone.