A 13-member ring has been arrested by police for manufacturing methamphetamine using pseudoephedrine and other ingredients from common cold medicine.

The Seoul Metropolitan Police Agency's Metropolitan Investigation Unit announced that it has arrested 13 individuals who manufactured 1.36 kilograms of methamphetamine using cold medicine, with four of them placed in custody.

Police explained that 1.36 kilograms of methamphetamine is an amount that can be administered to 40,000 people, valued at 4.2 billion won.

They are accused of extracting the pseudoephedrine component contained in cold medicine at an apartment in Pyeongtaek, Gyeonggi Province, which had many vacant units, and then mixing and processing it with sulfuric acid and hydrochloric acid to manufacture methamphetamine from April 2025 to June of last year.

Police stated that they also apprehended a herbalist who sold about 10,000 packs, or 630,000 tablets, of cold medicine to the ring while knowing the purpose was for manufacturing methamphetamine.