mostly takes the edge off of the stimulant effect and may enhance some of the disinhibitive qualities of kratom
(ie-become more chatty, social, etc). It does not contribute a great deal to kratom's euphoric side; any euphoric aspect of the kava is overwhelmed. Then again, SWIM
does not find any form of kava particularly euphoric. It works only as a mild anxiolytic and mild sedative for SWIM, even at strong doses. Perhaps to those more sensitized to the root's effects would be able to better assess any synergy. Certainly seems to be safe though.
SWIM mostly takes it to calm the jittery feeling SWIM sometimes gets after kratom too late at night. It has also been helpful with some axiety SWIM once got from too much kratom at once.