Cannabis appears to have been introduced to Thailand from India, with the similarity of the Thai name to the Indian term ganja cited as evidence. Cannabis has historically been used in south-east Asia as an ingredient, a kitchen condiment, a medicine, and a source of fiber.
Marijuana had been a traditional medicine for centuries before it was banned in the 1930s. Laborers were known to use it as a muscle relaxer. It was reportedly used to ease women's labor pains.
The possession, sale, and use of cannabis was criminalised by the Cannabis Act, B.E. 2477 (1935). The two most salient acts for practical purposes are the Narcotics Act 2522 (1979) and the Psychotropic Substances Act 2518 (1975).
- Martin, Marie Alexandrine (January 1975). "Ethnobotanical Aspects of Cannabis in Southeast Asia". In Rubin, Vera (ed.). Cannabis and Culture. Mouton Publishers. pp. 63–76. ISBN 9027976694. Retrieved 2018-12-12.
- Blair, Eric (2001-07-11). "History of Marijuana Use and Anti-Marijuana Laws in Thailand". Thailand Law Forum. Retrieved 2018-12-12.
- Kapoor, Kanupriya; Thepgumpanat, Panarat (2018-12-12). "Weeding out foreigners: strains over Thailand's legalization of marijuana". Reuters. Retrieved 2018-12-12.
- "พระราชบัญญัติกันชา พุทธศักราช ๒๔๗๗" (PDF). Royal Thai Government Gazette. 52: 339–343. 5 May 1935. Retrieved 6 December 2016.
- "Criminal Drug Offences in Thailand". Siam Legal. Retrieved 2018-12-12.