If you ever choose to do them, in a medical environment or not, I'd suggest limiting yourself to a few experiences at most. Consider setting, who you're with, and what you have to occupy yourself (music, activities, meditation, etc.) I wouldn't go into it with the expectation to become more intelligent, just having fun gave me many revelations. Research on the topic will find you an ocean of profound experiences but if you abuse LSD or mushrooms then it could seriously leave you worse than when you started. See "HPPD"