Peyote is a small, button shaped cactus native to Mexico and southern parts of the United States. Potent compounds in peyote, such as mescaline, cause it to have a hallucinogenic effect in humans.

Even with several tablespoons of peyote in me, by 3 in the morning, I’m fading. For almost six hours I have been sitting in a teepee in the Navajo Nation, the largest Indian reservation in the United ...

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American In 2002, on assignment for Discover Magazine, ...