South Korean illegal drug detection and enforcement

South Korean authorities have identified and targeted various forms of illegal drug activity through wastewater analysis and criminal investigations.

In July 2026, the Ministry of Food and Drug Safety (MFDS) reported that a survey of wastewater from 60 sites identified 31 different illegal substances. Synthetic cannabinoids were the most prevalent, accounting for 68% of detections. Methamphetamine was found in all 34 major treatment plants analyzed. Sampling near nightlife venues during the Halloween period also revealed a higher concentration of substances such as cocaine, MDMA, and ketamine.

Following these findings, law enforcement has moved to dismantle illegal distribution networks. Authorities dismantled operations involving the illegal online sale of prescription medications, including glutathione injections marketed for whitening. Additionally, the Busan Metropolitan Police Agency arrested individuals involved in the illegal sale of steroids, Viagra, and diet supplements, some of which were smuggled from countries such as Thailand. These operations involved falsifying inventory records and selling medications at significant markups via online forums.