More than twenty alkaloids have been isolated from kratom. The major indole alkaloid of Mitragyna speciosa is mitragynine with 66% of the total alkaloid content. In addition, 7-hydroxymitragynine (7- HMG) is a minor constituent but more than 10 times more potent than morphine.
Other compounds that have been isolated from Mitragyna speciose include speciociliatine, speciogynine, and paynatheine have been shown to modulate intestinal smooth function and behavioral response in animals.
The quantity and effects of kratom’s alkaloids are varying from strain to another, also according to the age of the plant and depending on the type of solvents used in extraction process.