Mounjaro tops 1.5 million prescriptions in 10 months, with teens among fastest-growing users

Mounjaro surpassed 1.5 million cumulative prescriptions in South Korea within 10 months of its launch, with more than half of all prescriptions concentrated among patients in their 20s and 30s. Prescriptions for teenagers have also risen sharply this year, fueling growing concern about misuse among adolescents and for cosmetic purposes.

People Power Party lawmaker Han Ji-a of the National Assembly's Health and Welfare Committee obtained Drug Utilization Review data from the Health Insurance Review and Assessment Service showing that Mounjaro — launched domestically in August last year — recorded a total of 1,501,161 prescriptions over the 10 months through May.

The figures are based on completed DUR checks, which medical institutions use to screen for duplicate prescriptions. Because Mounjaro and Wegovy are not covered by national health insurance, precise prescription volumes are difficult to track, and DUR data serve as a proxy for gauging prescription trends.

Monthly prescriptions climbed from 18,579 in August last year, the month of launch, to 273,140 in May — an increase of roughly 14.7 times.

By age group, patients in their 20s and 30s accounted for 52.9 percent of all prescriptions, or about 794,781 cases. Those in their 30s made up the largest share at 36.0 percent, followed by those in their 40s at 27.1 percent, those in their 20s at 16.9 percent and those in their 50s at 14.6 percent.

The rise in teen prescriptions was particularly striking. Monthly prescriptions for patients in their teens stood at just 82 at launch, crossed 1,000 in December last year and climbed from 1,739 in January to 2,594 in May — roughly a 1.5-fold increase within this year alone.

Mounjaro has also overtaken Wegovy, which launched about 10 months earlier, in cumulative prescription volume. Wegovy recorded about 1.23 million cumulative prescriptions from its launch in October 2024 through May, with patients in their 20s and 30s accounting for 46.4 percent of that total.

The medical community has repeatedly raised concerns about misuse of GLP-1 obesity drugs, noting a growing trend of use beyond patients with diabetes or severe obesity to those seeking simple weight loss or cosmetic results.

The government is reviewing whether to classify GLP-1 obesity drugs, including Mounjaro and Wegovy, as drugs of concern for misuse and overuse. Such a designation would tighten oversight of the prescribing and dispensing process.

"Mounjaro prescriptions have exceeded 1.5 million in just 10 months since launch, yet the government's response has amounted to little more than adding warning labels," Han said. "We need to shift the management framework away from retail-focused controls and toward prescription management using DUR, in order to protect treatment access for patients while preventing misuse by teenagers and for cosmetic purposes."