Shrooms and acid are both completely safe physically. The danger is all in the mental/psychological effects. A good golden rule to live by is "trip to live, don't live to trip." Trips can be wonderful for self-exploration, deeper understanding, and so on, but if you spend all your time either tripping or looking for drugs to trip off of, something has gone awry. Trips are a means, not an end.

E is an amazing drug, but it's physically not very good for you. Occasional use is probably okay, but even once a month is questionable. Save it for special occasions.