Specific types of naturally occurring mushrooms contain hallucinogenic chemicalspsilocybin and psilocin. These mushrooms are generally grown in Mexico and Central America and have been used in native rituals for thousands of years. Dried mushrooms contain about 0.4% psilocybin and only trace amounts of psilocin. Once ingested, 'shrooms generally cause feelings of nausea and other physical symptoms. Effects may include different perceptions of stimuli like touch, sight, sound, and taste. The effects are similar to LSD but milder. Mistakingly selecting poisonous mushrooms can cause death or permanent liver damage within hours of ingestion. You aren't ever in control of what happens inside your body after doing 'shrooms. So, you never know what might happen to you on the inside. You could get bad liver damage, but, that's just among all of the other things that science have and haven't found. There are, most likely, a lot of damages that can happen internally that they, and everyone else, don't know about. LSD is VERY, VERY dangerous.