Occasionally it is very hard as well as extremely hard to quantify a changa. One example is when preparing a changa from "copyright oil" extracted from some acacia which contains a mix of alkaloids, and harmalas in the shape of caapi leaf containing an not known number of harmala alkaloids, https://changadmtforsaleeurope35702.shotblogs.com/changa-copyright-for-sale-an-overview-50512739