Danish pharmaceutical company Novo Nordisk's obesity treatment Wegovy (active ingredient semaglutide) has been found to be more effective than Eli Lilly's zepbound (tirzepatide, known in Korea as mounjaro) in reducing the risk of cardiovascular disease, according to clinical trial results. Both companies have been competing to expand the treatment scope of Wegovy and zepbound to cardiovascular disease following diabetes and obesity, with Novo Nordisk claiming the advantage.
Novo Nordisk presented research findings at the European Society of Cardiology Annual Congress (ESC 2025) indicating that semaglutide reduces the risk of death from cardiovascular diseases such as heart attack and stroke by 57% compared to tirzepatide. The conference took place in Madrid, Spain, from 31st to 1st of last month.
Wegovy and zepbound are both GLP-1 (glucagon-like peptide-1) class obesity treatments. The GLP-1 hormone is secreted from the small intestine after meals, promoting insulin secretion and lowering blood sugar levels. The two drugs mimic this effect and induce a feeling of fullness, leading to weight loss. Originally developed as diabetes treatments, they have evolved into obesity medications due to their weight loss effects.
The clinical trial involved 21,250 participants aged 45 and older with obesity or overweight who did not have diabetes and had cardiovascular disease. The cardiovascular death risk for the group receiving Wegovy without interruption was 57% lower than that of the zepbound group. The number of instances of cardiovascular disease in the Wegovy group was 15 (0.1%), while in the zepbound group it was 39 (0.4%).
The average follow-up periods were 3.8 months and 4.3 months, respectively. When analyzing the total patients, including those who discontinued treatment mid-way, the risks were 56 occurrences for Wegovy compared to 83 for zepbound, indicating a 29% lower risk. This suggests that the patients who adhered to treatment experienced greater effectiveness.
Ludovic Helfgott, senior vice president at Novo Nordisk, noted on the 1st, "This research data shows that semaglutide is a GLP-1 based drug that offers unique advantages for patients with obesity and cardiovascular disease who do not have diabetes."
Among the experts who attended the conference, there was an analysis suggesting that weight loss and cardiovascular protective effects could be separate indicators. Earlier research comparing the weight loss effects of the two companies' drugs showed that zepbound was favored over Wegovy.
Heo Hye-min, a researcher at Kiwoom Securities, analyzed that "This study highlighted Wegovy's competitive advantage over zepbound," adding, "Novo Nordisk has strengths in its strategy of expanding indications while Eli Lilly is competing based on efficacy and convenience in the obesity sector."
In fact, Wegovy was approved by the U.S. Food and Drug Administration (FDA) as a treatment for metabolic associated steatotic liver disease (MASH) last month. Wegovy is the first GLP-1 treatment to be approved as a MASH treatment. Novo Nordisk's GLP-1 diabetes treatment Ozempic has already been recognized for its efficacy in reducing cardiovascular risks. Zepbound has yet to be approved for any other indications.
Eli Lilly plans to seek FDA approval based on research results confirming cardiovascular improvement effects for diabetes patients within this year. Lilly is also developing an oral obesity medication. The company recently reported that its orally administered GLP-1 candidate 'opoglyptin' resulted in an average weight loss of 10.5% in a phase 3 trial (72 weeks of administration at maximum dosage), and it will pursue global approval based on this.
Pharmaceutical companies can expand the indications of a single drug to treat multiple diseases or develop injections into oral medications to widen their market. Observers suggest that as companies continue these efforts, the obesity treatment market will continue to grow. Investment bank Goldman Sachs forecasts that the obesity treatment market will grow by an average of about 50% annually, reaching a size of $100 billion (approximately 139 trillion won) by 2030, comparable to the hypertension treatment market.