Mounjaro and Wegovy generate KRW 427 billion in 3 months

Mounjaro posts KRW 323.2 billion in Q1 sales, leading obesity drug market

Wegovy remains above KRW 100 billion for the 4th consecutive quarter, despite losing its lead

Mounjaro’s sales dominated by lower doses, Wegovy’s by higher doses

The new obesity treatments Mounjaro and Wegovy have taken over the Korean market. Mounjaro generated over KRW 323.2 billion in sales in just 3 months, while Wegovy surpassed KRW 100 billion in quarterly sales for the fourth consecutive quarter. Mounjaro patients showed a stronger demand for lower-dose products, whereas Wegovy patients recorded a higher share of high-dose prescriptions. Meanwhile, Saxenda, once the dominant obesity treatment, has seen its market influence decline dramatically.

According to IQVIA data released on June 11, Eli Lilly's Mounjaro recorded KRW 323.2 billion in sales during the first quarter, making it the top-selling obesity treatment in Korea. This figure was more than three times higher than that of Wegovy, which was KRW 104 billion, firmly establishing Mounjaro as the market leader.

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Mounjaro, which was released in Korea in August last year, is a dual agonist targeting both the glucose-dependent insulinotropic polypeptide (GIP) receptor and the glucagon-like peptide-1 (GLP-1) receptor. The drug lowers blood glucose levels before and after meals by stimulating insulin secretion, improving insulin resistance, and reducing glucagon secretion.

Mounjaro was first approved in Korea in June 2023 as a diabetes treatment. It was approved for the treatment of type 2 diabetes as an adjunct to diet and exercise for glycemic control. In August 2024, it gained an additional indication for chronic weight management in adults, to be used alongside a reduced-calorie diet and exercise regimen.

The drug generated its first sales of KRW 29.4 billion in the third quarter of last year and surged to KRW 191.6 billion in the fourth quarter, becoming the market leader in obesity treatment sales. Over the nine-month period from Q3 2025 through Q1 2026, cumulative sales reached KRW 544.1 billion, rapidly reshaping the obesity treatment landscape.

Mounjaro has also overtaken Wegovy and risen to the lead in the global obesity drug market. Last year, Mounjaro recorded worldwide sales of USD 23.07 billion (approximately KRW 33 trillion), significantly exceeding Wegovy's sales of DKK 79.1 billion (approximately KRW 18 trillion).

Industry analysis shows that obese patients in Korea have an increased demand for Mounjaro due to its superior weight-loss efficacy.

GLP-1 suppresses appetite by stimulating satiety centers in the brain and slows gastric emptying. GIP not only enhances insulin secretion but also promotes fat metabolism and synergistically helps reduce gastrointestinal side effects commonly associated with GLP-1 therapies.

Mounjaro demonstrated significant weight-loss benefits in the Phase 3 SURMOUNT-1 trial involving overweight adults without diabetes who had a BMI of at least 30 kg/m² or at least one weight-related comorbidity. In the trial, patients receiving Mounjaro experienced an average weight reduction exceeding 15% at Week 72, while those receiving the highest dose achieved weight loss of approximately 21% of body weight.

Mounjaro also outperformed Wegovy in the head-to-head SURMOUNT-5 study.  

Results showed that patients receiving Mounjaro (10 mg or 15 mg) achieved an average weight reduction of 20.2% at Week 72, compared with 13.7% among patients receiving Wegovy (1.7 mg or 2.4 mg).

Novo Nordisk's Wegovy may have lost its leadership position, but it continues to post quarterly sales exceeding KRW 100 billion.

Wegovy generated KRW 104 billion in Q1 sales, representing a 26.6% increase from the same period a year earlier. The drug contains semaglutide, a GLP-1 receptor agonist. Novo Nordisk developed Wegovy after observing substantial weight-loss effects during clinical trials of GLP-1-based diabetes treatments.

Following its launch in Korea in October 2024, Wegovy quickly became a commercial success. The drug generated KRW 62.3 billion in sales during the fourth quarter of 2024 and immediately became the market leader in obesity treatment sales.

By Q2 2025, Wegovy had achieved KRW 138.5 billion in quarterly sales, surpassing the KRW 100 billion milestone within just nine months of launch. It has now maintained quarterly sales above KRW 100 billion for four consecutive quarters. Even before entering Korea, Wegovy gained global notoriety as a weight-loss aid favored by celebrities, contributing to worldwide supply shortages. Novo Nordisk strengthened its commercial presence by signing a co-promotion agreement with Chong Kun Dang in September last year.

However, Wegovy's sales have declined for two consecutive quarters since peaking at KRW 142 billion in Q3 last year. Analysts attribute the slowdown to competition from Mounjaro and the impact of price reductions. After Mounjaro entered the Korean market in August last year, Wegovy reduced its supply price by approximately 40%. Since Q4 2024, Wegovy has generated cumulative sales of KRW 649.6 billion over an 18-month period. Combined cumulative sales of Mounjaro and Wegovy have now exceeded KRW 1 trillion.

Mounjaro and Wegovy showed contrasting prescribing patterns by dose strength. Mounjaro had higher sales volumes in lower dosages, while Wegovy had a higher market share in higher-dosage products.

Mounjaro is currently sold in four different strengths: 2.5mg, 5mg, 7.5mg, and 10mg. In the first quarter, a total of 3,868,149 units were sold, with 5mg and 2.5mg being the most popular, at 1,551,910 units and 1,474,823 units, respectively. The market shares for 5mg and 2.5mg were 40% and 38%, respectively, accounting for a total of 78%. In comparison, the higher-dose 7.5 mg and 10 mg products accounted for only 12% and 10% of Wegovy’s sales, respectively.

Wegovy is approved in five strengths: 0.25 mg, 0.5 mg, 1 mg, 1.7 mg, and 2.4 mg. Each pen contains enough medication for four administrations. For instance, the 0.25mg product contains a total of 1mg, which can be administered four times using a single pen. In the first quarter, the 2.4mg dosage held the highest sales volume share at 34%, followed by 1mg at 22% and 1.7mg at 15%. The lowest dosage, 0.25mg, had the smallest share at 12%.

It is analyzed that Mounjaro has a high share of low-dosage products intended for initial treatment due to its relatively late entry into the domestic market, whereas Wegovy, having been on the market for over a year, has a higher proportion of patients in follow-up treatment stages.

Some industry observers suggest that the growing trend of ‘dose splitting’ with Wegovy may be contributing to the strong preference for higher-dose products. Unlike Mounjaro, which is supplied as a single-use prefilled pen, Wegovy is a multi-dose injection pen that allows users to select and adjust the dose before administration. As a result, many patients reportedly receive higher-dose prescriptions and divide them into multiple lower-dose injections. In fact, supply shortages have risen for Wegovy's higher-dose products. The proportion of the 2.4 mg dose among total Wegovy sales volume increased 15 percentage points from 19% in the first quarter of last year.

The market positions of Saxenda and Qsymia, which dominated the obesity treatment market before the emergence of Wegovy, have shrunk significantly.

Novo Nordisk's Saxenda generated only KRW 900 million in first-quarter sales. Before the launch of Wegovy, Saxenda recorded KRW 15.1 billion in first-quarter sales in 2024, but more than 90% of that revenue disappeared within 2 years. Launched in Korea in 2018, Saxenda was the world's first obesity treatment approved as a GLP-1 analogue. It contains the same active ingredient, liraglutide, as the diabetes treatment Victoza, differing only in dosage and administration. Following its launch, Saxenda became the leading obesity treatment in Korea, recording KRW 42.6 billion in sales in 2019 and maintaining the top position for five consecutive years through 2023. However, the introduction of Wegovy and Mounjaro has reduced its market presence to a minimal level. Industry observers believe that Wegovy, another GLP-1-based therapy, has effectively absorbed most of Saxenda's market.

Meanwhile, Alvogen Korea's Qsymia posted KRW 7.1 billion in first-quarter sales, down 18.5% year-on-year. Launched in Korea at the end of 2019, Qsymia is a fixed-dose combination product containing phentermine and topiramate.’ Alvogen Korea acquired the domestic marketing rights from U.S.-based Vivus in 2017. Although Qsymia experienced a smaller sales decline than Saxenda, it remains far behind Wegovy and Mounjaro. Combined first-quarter sales of Saxenda and Qsymia totaled just KRW 7.9 billion, representing less than 2% of the combined KRW 427.2 billion generated by the newer obesity treatments Wegovy and Mounjaro during the same period.