European obesity group names semaglutide and tirzepatide first-line obesity drugs

The European Association for the Study of Obesity (EASO) said on Oct. 2, 2025 that semaglutide and tirzepatide should be the first medicines doctors reach for in treating obesity and most of its complications, in a guideline published in Nature Medicine ^[1][2]. The recommendations are non-binding on individual countries ^[1].

Semaglutide is the active ingredient in Novo Nordisk's Wegovy, Ozempic and Rybelsus. Tirzepatide is sold as Zepbound and Mounjaro by Eli Lilly ^[1][2]. The guideline says the two drugs are effective enough to be the first choice in almost all cases where substantial weight loss is needed. When a lesser degree of weight loss is required, other options can be considered, including liraglutide, naltrexone–bupropion, and phentermine-topiramate ^[1][2].

Recommendations differ by condition

The authors reviewed earlier clinical trial results, judging each medicine on weight loss, safety, and how well it worked in people with specific complications. The algorithm was built from evidence available up to Jan. 31, 2025, and sorts complications into two groups: mechanical problems caused by excess fat mass, and metabolic or immune problems ^[2].

For the mechanical group, tirzepatide is recommended first for people with obesity and obstructive sleep apnea, based on randomized trial evidence. Semaglutide is preferred for people with knee osteoarthritis, based on demonstrated reductions in pain ^[1][2].

For the metabolic group, semaglutide is recommended first for people with established cardiovascular disease, based on evidence of reduced major adverse cardiovascular events. Either tirzepatide or semaglutide is recommended for people with prediabetes or type 2 diabetes. Tirzepatide is recommended in metabolic dysfunction–associated steatotic liver disease, though a phase 3 trial published after the cutoff date suggests semaglutide may soon join as a first-line option there ^[2]. For heart failure, current data are limited but suggest either drug may be appropriate ^[2].

The class was originally developed to treat type 2 diabetes ^[1].

"Although no treatment algorithm can replace the nuanced clinical judgment necessary for comprehensive patient care," the guidelines can support decisions about obesity treatment, coauthor Dr. Andreea Ciudin of Vall d'Hebron University Hospital in Barcelona said in a statement ^[1]. EASO president Professor Volkan Yumuk of Istanbul University-Cerrahpaşa said the group intends to update the algorithm regularly as evidence changes ^[1]. Almost all of the authors reported financial relationships with at least one of the manufacturers ^[2].

Why it matters for patients

The guideline gives doctors a condition-by-condition starting point, rather than treating obesity as one problem with one answer. That means two patients with the same body weight could be pointed toward different drugs depending on whether they have sleep apnea, knee pain, heart disease or diabetes ^[1][2].

The authors also argue that cost should be weighed against the cost of not treating obesity early, which they say allows progression to complications and organ damage ^[1][2]. They add that obesity care should look beyond weight loss to mental well-being, physical fitness, social functioning and quality of life ^[1][2].

The guideline does not cover dosing, US insurance coverage or US prescribing rules, and the recommendations carry no authority over American practice. In June, four US groups — the American College of Lifestyle Medicine, the American Society for Nutrition, the Obesity Medicine Association and The Obesity Society — jointly advised that GLP-1 treatment must be accompanied by nutritional and lifestyle strategies. That advisory cited gastrointestinal side effects, risk of nutrient inadequacies, muscle and bone loss, high costs, frequent discontinuation and weight regain as challenges limiting long-term success ^[1].

What happens next

EASO has not set a date for its next update; it said only that it plans to revise the algorithm regularly ^[1][2]. Novo Nordisk shares rose 2.2% at 1007 GMT on the day of publication ^[1]. No changes to US labeling or coverage have been announced in connection with the guideline.