There are more than 40 compounds in M. speciosa leaves,[6] including many alkaloids such as mitragynine (once thought to be the primary active constituent), mitraphylline, and 7-hydroxymitragynine (which is currently the most likely candidate for the primary active chemical in the plant), and mitragynine pseudoindoxyl.[13][14] Other active chemicals in M. speciosa include raubasine (best known from Rauwolfia serpentina) and some yohimbe alkaloids such as corynantheidine.