Novo’s Wegovy shows heart benefit but Korean doctors see Lilly’s Mounjaro as stronger on weight loss

Novo Nordisk unveiled new evidence last month that its semaglutide injection, sold as Wegovy, works under East Asia’s lower obesity threshold. The company also presented real-world data showing Wegovy reduced the risk of heart attack, stroke and death more than Eli Lilly’s tirzepatide, marketed as Mounjaro.

But in Korea, doctors said the real advantage lies elsewhere.

Lilly’s GIP/GLP-1 dual agonist hit the Korean market last month with approvals for diabetes and obesity, followed two weeks later by a label for sleep apnea.

At a press briefing in Seoul on Tuesday, endocrinologists argued that its ability to cut both blood sugar and body weight could matter more than cardiovascular outcomes in a country where bariatric surgery is rare and most diabetics still fail to meet treatment goals.

Lee Seung-hwan, professor of endocrinology and metabolism at Seoul St. Mary’s Hospital, speaks Tuesday at Lilly Korea’s press conference at Lotte Hotel Seoul marking the launch of Mounjaro. (Courtesy of Lilly Korea)

“In weight loss, Koreans are likely to see even better results with Mounjaro,” said Lee Seung-hwan of endocrinology and metabolism at Seoul St. Mary’s Hospital, citing trial data that showed patients lost an average of 22.5 percent of their weight at the top dose.

Doctors emphasized that the benefit is not cosmetic but a way to delay expensive surgery and blunt the complications of obesity.

Novo, for its part, is bolstering Wegovy with new data. At the European Society of Cardiology meeting in Madrid, the company reported on Sunday that Wegovy cut the risk of heart attack, stroke and death by 57 percent compared with tirzepatide.

And on Aug. 15, researchers led by Seoul National University Bundang Hospital (SNUBH) confirmed in Lancet Diabetes & Endocrinology that semaglutide works under Asia’s lower BMI threshold of 25, with patients losing 16 percent of their body weight after 44 weeks and waistlines shrinking nearly 12 centimeters. More than half cut at least 15 percent of their weight, far outpacing placebo.

Even so, Korean clinicians cast tirzepatide as the heavier hitter on blood sugar control. In Lilly’s SURPASS program, up to 90 percent of patients reached the Korean Diabetes Association’s HbA1c target of 6.5 percent or lower, and about half of those on the highest dose dropped into the normal range below 5.7 percent.

Professor Lee said the dual-acting peptide “gets more patients not only to goal but into remission territory,” adding that pairing 15 percent weight loss with normalized blood sugar “changes the prognosis.”

Waist circumference provided another point of comparison. Lee noted that tirzepatide at 5 milligrams, its lowest maintenance dose, showed reductions on par with Wegovy’s full 2.4 milligram dose. “I expect the 5 milligram dose will be most widely used in Korea,” he said, “though titration up to 15 milligrams is possible.”

Professor Choi Sung-hee of endocrinology at SNUBH said at Tuesday's conference that dual effect explains why drugs like tirzepatide and semaglutide are being separated from older GLP-1 drugs. “Every 10 to 15 percent drop in body weight translates into a 1 to 2 percent HbA1c reduction, and every 1 percent HbA1c drop cuts complication risk,” she said.