There are many unanswered questions concerning the toxicity of these mushrooms. It has been suggested, and there is some evidence to support this, that the toxicity may vary according to location and season. The drying process turns ibotenic acid into muscimol, multiplying the potency by 5 or 6, and reduces bad side-effects. The effects are distinctly different from psilocybin, LSD or mescaline, and may last up to 8 hours. Side effects often include nausea, slight loss of balance and coordination, and drowsiness.
Smoking produces a more rapid effect of shorter duration.
Anyone who wants to mess with these should learn a lot more about them than the above.