
Beug and Bigwood of The Evergreen State College in Olympia, Washington analyzed the levels of psilocybin and psilocin in 20 species of wild mushrooms from the Pacific Northwest. They tested species known to be used for entheogenic and recreational purposes. They found total psilocybin and psilocin levels from 0.1% to nearly 2.0% by dry weight. Overall, the levels varied from one collection to another by more than a factor of seven.