All are derived from natural products: LSD from a fungus that often contaminates wheat and rye flour Psilocybin from several types of mushrooms Mescaline from the peyote cactus Many synthetic hallucinogens ("designer drugs") are based on naturally occurring tryptamine or phenylethylamine molecules such as N, N - dimethyltryptamine (DMT) and 5-methoxy - N, N - diisopropyltryptamine (5-MeO-DIPT).