Recent advancements in obesity treatments have introduced highly effective medications, with the prospect of even more potent experimental treatments set for testing in 2026.

“We are witnessing an ambitious new phase in obesity treatment that promises improved health outcomes for numerous patients,” states Laura Heisler from the University of Aberdeen, UK. “Obesity is linked to severe health complications, including cancer, heart disease, and type 2 diabetes. A modest 5% reduction in body weight can significantly decrease these health risks.”

The first major weight loss drug, semaglutide, was initially approved as a diabetes treatment in 2017 under the name Ozempic. In 2021, it received approval for weight management as Wegovy.

Semaglutide functions by imitating the natural hormone GLP-1, which binds to brain and pancreatic receptors, helping to curb appetite and slow gastric emptying. Alongside its weight loss benefits, semaglutide has demonstrated positive cardiovascular effects and potential in managing conditions like substance addiction. However, common side effects like nausea can lead to discontinuation of the drug.

In 2023, Tirzepatide, marketed as Mounjaro for diabetes, secured approval for weight loss under the name Zepbound. Enhancing semaglutide’s effectiveness, Tirzepatide operates by mimicking both GLP-1 and another hormone, GIP, which is involved in energy management. Like semaglutide, it has comparable side effects.

In clinical trials, semaglutide resulted in an average weight reduction of 14% over 72 weeks, while participants using tirzepatide achieved a 20% reduction. Notably, regaining lost weight is common once the medication is stopped.

Looking ahead, more dual-action and even triple-action medications are in development. A promising candidate for 2024 approval is Kaglisema, which merges semaglutide with Caglilintide, a drug that stimulates fullness through amylin mimicry.

In a trial with over 3,400 adults, those taking Kaglisema achieved a weight loss of 20% after 68 weeks, outperforming both semaglutide (15%) and Caglilintide alone (12%), indicating strong potential.

Additionally, a drug named amicretin is undergoing development. Similar to CagliSema, it mimics both GLP-1 and amylin, but uses a single molecule that binds to both receptor types.

In preliminary trials involving 125 participants, amicretin users experienced an average weight loss of 24% after 36 weeks, suggesting superior effectiveness compared to tirzepatide, although final-stage trials won’t commence until 2026.

Moreover, the “triple G” drug letartortide activates three hormones to facilitate fat release: GLP-1, GIP, and glucagon. In a study of 338 individuals, those on the highest dose experienced an average weight loss of 24% after 48 weeks. Results from late-stage trials will be crucial for assessing letartortide’s approval timeline, expected in late 2026 or beyond.

It’s important to note that weight loss results from various clinical studies aren’t directly comparable due to differences in participant criteria, study durations, and dosages. Moreover, average results can mask significant variability in individual responses to GLP-1 drugs; while some experience negligible effects, others see remarkable weight loss.

As many as 100 new weight-loss drugs are currently in development for 2026 and beyond as companies strive to capture a share of the lucrative market. These innovations often focus on diverse combinations of existing targets, such as GLP-1, GIP, glucagon, and amylin receptors, or explore new mechanisms entirely.

Research is also addressing adverse effects, such as the evidence indicating some weight loss from GLP-1 drugs may come from muscle rather than fat. For instance, a recent trial earlier this year combined semaglutide with bimagrumab, a muscle growth inhibitor, seeking to counterbalance these effects.

“The prospect of emergent, highly effective drugs with fewer side effects is indeed exciting,” says Heisler.