South Korea’s rapidly expanding market for weight-loss drugs is creating a new regulatory and distribution challenge, as surging consumer demand for Wegovy and Mounjaro drives a sharp increase in illegal imports. For U.S. drugmakers and investors, the trend highlights both the commercial potential of Asia’s obesity-treatment market and the risks created when supply and access fail to keep pace with demand.
In the first six months of 2026, South Korean customs officials intercepted 4,155 illegal shipments involving obesity drugs including Wegovy and Mounjaro, the Korea Customs Service said Aug. 24. That was about 3.5 times the 1,189 cases recorded during all of 2025.
The increase marks a dramatic shift since the drugs entered the South Korean market. Customs authorities recorded only four illegal-import cases in 2024. The number jumped to 1,189 in 2025 and surpassed 4,000 in the first half of 2026 alone, bringing the cumulative total since 2024 to 5,348.
The figures underscore the strength of demand for a class of drugs that has rapidly expanded beyond diabetes treatment into mainstream obesity care. They also illustrate how regulatory restrictions and limited access can push consumers toward overseas websites and informal supply channels, a dynamic that pharmaceutical companies and investors are watching as demand for GLP-1 drugs expands globally.
Formal imports through commercial importers have remained far smaller. From 2024 through June 2026, customs officials recorded just 596 shipments that were properly cleared through importers—14 in 2024, 191 in 2025 and 391 during the first half of 2026.
International mail accounted for most of the illegal activity. Customs officials intercepted 3,489 cases involving postal shipments during the first six months of 2026, compared with 1,046 in 2025 and just two in 2024. Postal shipments represented 84.8% of all illegal-import cases recorded since 2024.
The pattern suggests that consumers are increasingly buying obesity drugs individually from overseas websites and attempting to have them delivered through international mail, rather than obtaining them through authorized domestic channels.
Imports carried by travelers have also risen. Customs authorities recorded 656 such cases in the first half of 2026, compared with 134 in 2025 and one in 2024. Express-cargo shipments accounted for 10 cases in the first half of 2026, compared with nine in 2025 and one in 2024.
South Korean customs rules generally allow individuals to bring in certain medicines for personal use, subject to limits such as six bottles or a three-month supply. Wegovy and Mounjaro face stricter treatment because they are classified by the Ministry of Food and Drug Safety as “harmful drugs.” Importers must obtain a recommendation exempting them from applicable import requirements.
Customs authorities block Wegovy, Mounjaro and other drugs designated by the ministry regardless of the quantity being imported. Products intercepted during customs clearance are held and destroyed.
The crackdown adds another layer to the competitive landscape for the global obesity-drug market, where pharmaceutical companies are racing to expand manufacturing capacity, distribution networks and access as demand outpaces supply in many markets. For investors, South Korea’s experience offers a visible example of how regulatory bottlenecks and consumer demand can reshape the path from a blockbuster drug’s launch to its actual availability to patients.
“Unauthorized imports of Wegovy and Mounjaro constitute serious violations that can be punished under the Customs Act,” a Korea Customs Service official said. “We will thoroughly block the illegal entry of harmful drugs at the border.”
