Potential for GLP-1 drugs to transform medicine explodes in 2025

Previously hailed – or derided – as weight-loss aids for the rich and famous, drugs such as Mounjaro, Wegovy and Ozempic have taken on a much larger role in 2025. No longer seen just as treatments for obesity and type 2 diabetes, Ozempic has gained approval in the United States for the treatment of kidney and cardiovascular disease. But far from stopping there, the evidence that these drugs could transform almost every aspect of medicine has truly exploded this year.

There were already hints that the drugs, which mimic a gut hormone called glucagon-like peptide-1 (GLP-1), could do much more than just manage diabetes and obesity, with studies in 2024 suggesting they reduced the risk of heart attacks and strokes, alleviated depression and anxiety, and even slowed cognitive decline.

At first, many thought it was just a side effect of weight loss, as obesity is a major risk factor in many conditions. But by early 2025, it was clear that something else was happening. More detailed studies have shown that people experience health benefits regardless of the weight lost.

Researchers have begun to uncover how GLP-1 drugs work across multiple pathways, several of which are linked to inflammation. They also appear to influence metabolism and brain circuits involved in motivation, reward and mood, which could explain their new benefits against alcohol dependence and depression.

Until recently, much of this evidence came from animal experiments or observational studies. But 2025 saw a wave of larger randomized trials examining the broader effects of these drugs.

In January, researchers reported that people with diabetes taking GLP-1 drugs alongside standard treatment had a lower risk of 42 conditions – including dementia and muscle pain – compared to those taking standard treatment alone. It wasn’t all good news: They were also linked to an increased risk of 19 conditions, including kidney stones, but overall the benefits outweigh the harms.

Some of the most striking discoveries of the last year concern the brain. The suspected link between GLP-1 drugs and reductions in addictive behaviors has been confirmed by the first randomized clinical trial directly testing the idea.

In a nine-week study of 48 people with alcohol use disorder, those given semaglutide — Ozempic and Wegovy’s drug — drank less and reported fewer cravings than those given a placebo. “We are very excited about the progress,” says Tony Goldstone of Imperial College London. “We don’t have a lot of drugs for addiction, and [GLP-1 drugs] are already permitted for other conditions, so we know they are reasonably safe.

Other cognitive benefits also emerged this year. In April, a meta-analysis of 26 clinical trials involving more than 160,000 people found that GLP-1 drugs significantly reduced the risk of all types of dementia. This followed a trial led by Paul Edison, also at Imperial College London, showing that treating people with Alzheimer’s disease for a year with the GLP-1 drug liraglutide – found in the brand drugs Saxenda and Nevolat – halved brain shrinkage and slowed cognitive decline by 18 per cent compared to a placebo.

Edison believes that Alzheimer’s disease results from overlapping disease processes, rather than a single cause. GLP-1 drugs may work by acting on several of them, he says, by protecting neurons via kinase pathways, which are vital to the cell’s response to stress; reduce cellular damage by improving insulin sensitivity; and reduce inflammation.

But the good news doesn’t stop there. Later in April, the GLP-1 drugs became the first pharmaceutical treatment to show clear benefits for people with a severe form of nonalcoholic fatty liver disease, where fat buildup triggers inflammation and scarring that can lead to cirrhosis and cancer.

Even aging came into play. In a small trial of people with an HIV complication that accelerates aging, those who received Ozempic injections for 32 weeks were on average 3.1 years biologically younger at the end of the study, while there was no change in the placebo group.

Varun Dwaraka of the diagnostic company TruDiagnostic in Lexington, Kentucky, who worked on the study, again emphasizes that the effects are not just a product of weight loss. “Although weight loss may appear to be part of the biological aging story, early evidence, together with what is known about GLP-1 biology, suggests that there is an independent layer of metabolic improvements, which translate into biological age improvement,” he says.

And there’s no sign of slowing down. Toward the end of the year, studies linked GLP-1 drugs to improvements in age-related cataracts, psoriasis, and even the renewal of stem cells vital for immune system support.

This Swiss army knife of a drug class will undoubtedly yield further revelations in 2026, as researchers work to understand how one type of treatment can influence so many conditions – and where its limits really lie. What is clear, Goldstone says, is that while larger and longer trials are needed, “we are moving in the right direction.”