Luckily legal prodrugs of LSD exist, compounds which metabolize into LSD before reaching the brain like 1P-LSD and ALD-52. In the United States, you can order these off the clearnet without fear of legal repercussions, unlike shrooms. (although psilocin has its own collection of legal prodrugs available including, for example, 5-MeO-DMT and 4-HO-MET).
A lot of that stuff is toxic. People take these drug analogues, get sick, then blame the base molecule their government scared them from getting. Anything that's a prodrug has to be processed by your liver first. It puts extra strain on your liver, whereas the original molecule is already what you wanted.