"Mitragyna speciosa Korth (of the Rubiaceae family) is a large tree found in tropical and sub-tropical regions of South-East Asia. In Thailand, the tree known as ‘Kratom’ is found throughout the country but predominantly in the southern region, although the growing and harvesting is prohibited.
"Kratom contains many alkaloids including mitragynine, mitraphylline, and 7-hydroxymitragynine. Traditionally, kratom had been used in Malaysia and Thailand by labourers and farmers to enhance productivity, but also as a substitute to opium and in traditional medicine, allegedly due to its morphine-like pharmacological effects. However, its use as a new psychoactive substance in the global market has been recently reported.
"In the early 2000s, products labelled as ‘kratom acetate’ or ‘mitragynine acetate’ became available in Europe, although it was found that neither of them contained mitragynine. Caffeine and synthetic O-desmethyltramadol (an active metabolite of tramadol) were found in products under the name ‘krypton’.84 More recently, products containing kratom have been sold as ‘incense’ for their psychoactive effects, but concentrations of the active components mitragynine and 7-hydroxymitragynine in these products differ depending on the variety of the plant used, the environment and the time of harvesting."
UN Office on Drugs and Crime. "The Challenge of New Psychoactive Substances: A Report from the Global SMART Programme". Vienna, Austria: UNODC Laboratory and Scientific Section, March 2013.