Ketosterols represent a rather large group of phytochemicals, so it would be tough to generalize about all of them. Eg. ketosterols in Rhodiola behave far differently in the body than do Ketos's from Cissus. Both plants posses an array of ketos with each specific keto producing a different effect. Intuitively, there are probably some bad ketos out there that have yet to be id'ed, however most seem to be either harmless or beneficial.