Thailand List of Controlled Narcotic Drugs is established by the Ministry of Public Health (MOPH) under the Narcotics Act B.E. 2522 (1979) and the Narcotics Code 2021, and is jointly administered by the Food and Drug Administration (FDA) and the Office of the Narcotics Control Board (ONCB). The list classifies narcotic substances into the following five categories:
Category 1: Highly dangerous narcotics, such as heroin. All forms of import, export, production, distribution, and possession are strictly prohibited; commercial use is entirely banned.
Category 2: Generally controlled narcotics, including morphine, cocaine, codeine, etc. Businesses engaged in relevant operations (import, export, production, distribution, possession) must apply for an annual operating license from the FDA Narcotics Control Division, and a separate single-use permit is required for each individual import/export transaction. License holders must regularly submit audit records and reports to the FDA. Licenses must be renewed within 30 days before expiration; failure to do so will be deemed unlicensed operation.
Category 3: Medicinal formulations containing Category 2 narcotics. Specialized licenses are required for import, export, and production. For specific chemicals (e.g., sodium chloride, benzyl cyanide, benzyl chloride), registration requirements must be met.
Category 4: Chemicals used in the manufacture of Category 1 and 2 narcotics, such as acetic anhydride. Their import and export require a license and are subject to continuous monitoring.
Category 5: Other narcotics not falling under the previous four categories. From June 2025, cannabis was reclassified into this category and is restricted to physician prescription only. Cannabis extracts with THC content exceeding 0.2% remain controlled substances. Commercial research, export, sale, or processing requires the appropriate license.
