Kratom is a South East Asian tree and is a member of the Rubiaceae family, which is the same family as coffee comes from.
Reports from the 1830’s claim that it was used by natives of Malaysia as an opium substitute and has since been use in Thailand and South East Asia, among the working class for a numbing, stimulating effect.
It contains many alkaloids including Mitragynine and Mitraversine.
The effects of kratom are both sedation and stimulation, feelings of well being and improved concentration.
It binds to opium receptors in the brain and produces similar feelings to opium based products but milder. The main difference between kratom and other opiates is that Mitragynine prefers delta opiod receptors and other opiates bind to mu opiod receptors. At higher doses, mitragynine increasingly stimulates mu opiod receptors. This could be why kratom is stimulating at low doses and has a more narcotic effect in larger doses. In the “Thai Narcotic Book” kratom is described as being ‘weaker that morphine and less harmful than cocaine.