Some psychedelics are more unpredictable than others, and incidentally these seem to be the ones that are hyped the most. LSD is much more predictable than mushrooms for instance, and is well researched partially because of that. The seems generally true for synthetic vs naturally occurring substances across the board, though there are plenty of horrible synthetic drugs like bath salts, synthetic weed. Advocates seem favor this as it allows them a no true Scotsman defense. “You didn’t get real ayauasca”, or with cannabis the hand wavey talk of the “entourage effect.” The biggest problem facing psychedelic research are the researchers involved. They have little credibility, almost like that’s their intention.