They were developed as diabetes drugs, then their potential for promoting significant weight loss became apparent. And now study after study seems to suggest that drugs such as Ozempic and Wegovy could have all sorts of health benefits, leading some scientists to hail them a breakthrough that could transform many chronic diseases of ageing. But what’s the mechanism for these effects and is it caused by more than weight loss? The Guardian’s science correspondent Nicola Davis tells Madeleine Finlay what is known so far. Help support our independent journalism at theguardian.com/sciencepod