In September 2011 the Government of the Republic of Korea introduced a temporary scheduling system that was added to the Act on the Control of Narcotics. Under the Act, the Commissioner of the Korean Food and Drug Administration may designate substances deemed necessary to be urgently handled or controlled as if they were narcotics, etc., due to the concern of harm and danger to the health that may arise from the misuse or abuse of the substance as temporary narcotics. Prior to the designation of a substance as a “temporary narcotic, etc.” the Commissioner shall consult with the relevant agencies determined by Presidential Decree and make a prior announcement in the official Gazette and internet homepage for not less than one month. The temporary control of a substances is possible for a maximum period of three years (renewable). The synthetic cathinone MDPV (3,4-Methylenedioxypyrovalerone) was the first substance subject to temporary schedule at the end of 2011. However, several NPS had been previously listed as “psychotropic drugs” under the Act on the Control of Narcotics since the mid 2000s. For the definition of psychotropic drugs, see Article 2(4) (a-b) of the Act on the Control of Narcotics. NPS regarded as psychotropic drugs and subject to control include JWH-018 & its analogues, CP-47497 & C6, C8, C9, BZP, 2C-D, 2C-E, MeOPP, HU-210, 4-Acetoxy-DiPT, mCPP, TFMPP, Psilocybin, phencyclidine analogues, etc. Between April and October 2014, 30 NPS, including synthetic cannabinoids, phenethylamines, ketamine and other substances were placed under temporary control for three years, pursuant to the Act on the Control of Narcotics of the Republic of Korea. This includes substances such as XLR-12; ADB-PINACA; FDU-PB-22; AB-CHMINACA; 5-fluoro-AMB; 2C-N; βk-2C-B; Acetylfentanyl and LY2183240. The Act prohibits the possession, management, import and export, trade, assistance in the trade, or the giving or receiving of materials that contain a temporary scheduled substance (see Bulletin No. 2014-369 "Law on Narcotics management"). In 2016, the benzodiazepine diclazepam was placed under temporary control.

Between 2011 and 2020, a total of 221 substances were designated as temporary class drugs, and 115 were reclassified as controlled substances. The most recent temporary scheduling took place on 16 July 2021 for 17 substances, including AL-LAD, 25H-NBOMe, and U-48800.