Korea Adverse-Event Reports Involving Wegovy and Mounjaro Top 1,700
核心洞察
Government data submitted to a Korean lawmaker show 1,780 adverse-event reports for Wegovy and Mounjaro combined since their respective Korean launches.
Wegovy, containing semaglutide, accounted for 944 reports from its October 2024 launch through March 2026, while tirzepatide-based Mounjaro recorded 836 since August 2025.
Adding 518 reports for liraglutide-based Saxenda, the three injectable obesity (搜索) drugs total 2,298 reports, with vomiting, diarrhea and injection-site pain among the most frequent symptoms.
Adverse-event reports linked to the injectable obesity (搜索) drugs Wegovy and Mounjaro have reached 1,780 in Korea, according to government data submitted to ruling Democratic Party of Korea Rep. Kwon Chil-seung. Wegovy, which contains semaglutide, accounted for 944 reports from its Korean launch in October 2024 through March 2026, with 49 in 2024, 672 in 2025 and 223 in the first three months of 2026. Mounjaro, which contains tirzepatide and acts on both GIP and GLP-1 receptors, was launched in Korea in August 2025 and was associated with 836 reports over the same period, 345 last year and 491 in the first quarter of this year.
Including 518 reports involving liraglutide-based Saxenda between 2024 and March 2026, the combined total for the three injectable obesity (搜索) drugs reached 2,298. Frequently reported symptoms included vomiting, diarrhea, injection-site pain, headaches and indigestion. The ministry stressed that an adverse-event report records a health problem observed after a drug was used and does not by itself prove a causal link. Kwon said adverse-event reports alone cannot establish a causal relationship with a medicine, but added that closer oversight is needed given growing use of obesity drugs and the accumulation of a substantial number of reports.
Prescribing has expanded rapidly. Mounjaro was prescribed about 1.84 million times through July this year, compared with 394,365 prescriptions in 2025, when it was available for only the final five months of the year. Wegovy recorded 482,071 prescriptions through July, following 828,209 in 2025. The figures represent prescription records, not the number of individual patients. Separate Korea Customs Service (搜索) data showed authorities intercepted 5,030 attempts to bring obesity (搜索) drugs into the country illegally through August, more than four times the 1,189 cases recorded in all of 2025. Tests on nine suspected counterfeit Mounjaro products sent from India found inconsistent levels of tirzepatide and unidentified impurities in some samples, and the products had been shipped without the required cold chain.
Source: The Korea Herald