San Pedro Cutting Pachanoi (Trichocereus) – 35 to 45 cmSan Pedro is a cactus from the psychedelic Trichocereus family. The active ingredient in these mind-altering cacti is mescaline. The use of this cactus for spiritual purposes and to treat various ailments dates back thousands of years. While there is a possibility that experiments with psychedelic natural substances have occurred, unfortunately, there is no archaeological evidence to support this.