mushies are all-natural, hence growing out of the ground.
your main concern is 'are they the right type', there is a very small percentage of edible shrooms (psychoactive included).
secondly 'how potent?' if too potent, too much can be ingested, possibly leading to a bad trip, the breaking down of the ego, or a mental break down. (reported more with large doses and continual use in LSD, but possible in shrooms)
i havent read on the long term effects of musihes, but after a week long binge, i am totally permafried. seeing unusual patterns is things that dont even have patterns. and my pot highs are waaayyy more psychedelic now too.
i do know for a fact that they relieve cluster headaches.
dont let this post detur you from the experience, mushrooms are absolutly amazing, and everyone should experience them once.