Kratom Leaves Also know as ketum,kakuam,ithang and Thom Mitragyna speciosa is a leafy tree that grows from 3-15 meters tall. Its leaves contain mitragynine and was traditionally chewed as an opiate substitue and stimulant in thailand and south-east asia. The alkaloid content of the leaves of mitragyna speciosa is about 0.5% about half of which is mitragynine.an average leaf weighs about 1.7 grams fresh or 0.43 grams dried. Twenty leaves contain approximately 17mg of mitragynine. Not for human consumption. You must be over 18 to buy this product is supplied for research only.