The weight-loss drugs on trial in 2026 may trump Ozempic and Zepbound

Over the past few years, highly effective drugs have emerged to treat obesityand it is hoped that experimental treatments tested in 2026 will prove even more effective.

“We are witnessing an exciting new chapter in obesity treatment that is improving the health and lives of many patients,” says Laura Heisler at the University of Aberdeen, UK. “Obesity is responsible for some of the world's most serious diseases: cancer, heart disease and type 2 diabetes. Even a modest 5 percent reduction in body weight can reduce these risks.”

The first weight loss blockbuster drugs was a small protein called semaglutide. It was approved in 2017 to treat diabetes and is marketed as Ozempic. It was also approved for weight loss in 2021 and sold under the name Wegovy.

Semaglutide mimics the action of a natural hormone called GLP-1 by binding to receptors in the brain and pancreas, reducing appetite and slowing the passage of food through the stomach. It also turned out that direct cardiovascular benefitsin addition to the benefits associated with weight loss, and may also help treat other conditions such as drug and alcohol addiction. However, semaglutide may have side effects, including nausea and vomiting, which cause many people to stop taking it.

Another drug called tirzepatide (marketed as Munjaro for diabetes) was also introduced in 2023. approved for weight lossmarketed as Zepbound. Tirzepatide is superior to semaglutide by having a dual effect: it mimics GLP-1 and another hormone called GIP, which is involved in regulating energy use and storage. Side effects are similar to semaglutide.

IN personal testSemaglutide reduced people's weight by an average of 14 percent over 72 weeks, while tirzepatide reduced it by 20 percent. Other studies show that lost weight usually comes back if you stop taking medications.

Next in line are drugs with double and even triple action. CagriSema, a combination of a drug called cagrilintide that makes people feel full by mimicking the effects of a hormone called amylin, with semaglutide could be approved next year.

In a study of more than 3,400 adults, people who took CagriSema lost 20 percent of your weight at 68 weeks, compared with 15 percent taking semaglutide alone and 12 percent taking cagrilintide only. This suggests it is on par with tirzepatide, although various trials are ongoing.

A similar drug called amicretin is also in development. Like CagriSema, amicretin mimics both GLP-1 and amylin, but it consists of a single molecule that can bind to both GLP-1 and amylin receptors, rather than two molecules.

In a small early trial of amicretin, which included just 125 people, people failed. 24 percent of their weighton average after 36 weeks. This suggests it may be better than tirzepatide, but it will be some time before this becomes clearer, with final-stage trials not starting until 2026.

There is also a “triple G” drug, retatrutide, which mimics three hormones: GLP-1, GIP and glucagon, which triggers the release of fat deposits. In a study of 338 people, those who received the highest dose lost on average 24 percent of their weight, after 48 weeks. Again, this is promising, but much depends on the results of the final trials already underway. It is possible that retatrutide will be approved at the end of 2026, but it could be later.

It should be noted that the figures for weight loss Results from different studies may not be directly comparable because of differences in, say, how participants were selected and duration and dosage. The averages also mask wide variations in how people respond to GLP-1 drugs: some don't respond at all, while others see dramatic weight loss.

There are more than 100 weight-loss drugs in development beyond 2026 as pharmaceutical companies race to gain share of the lucrative market. Many of them target different combinations of the existing four targets—GLP-1, GIP, glucagon receptors, and amylin—but some involve other targets and mechanisms.

Others try to compensate for unwanted effects, such as the fact that some of the weight people lose when taking GLP-1 drugs is due to muscle loss rather than fat loss. For example, a trial that ended earlier this year a combination of semaglutide and bimagrumab, which blocks the muscle growth inhibitory receptor, although the results have not yet been announced.

“What's really exciting is that there are more promising drugs on the horizon that may provide even greater benefits with fewer side effects,” says Heisler.