Harmaline-containing plants and tryptamine-containing plants are used in ayahuasca brews. The inhibitory effects on monoamine oxidase allows dimethyltryptamine (DMT), the psychoactively prominent chemical in the mixture, to bypass the extensive first-pass metabolism it undergoes upon ingestion, allowing a psychologically active quantity of the chemical to exist in the brain for a perceivable period of time.[5] Harmaline forces the anabolic metabolism of serotonin into N-acetylserotonin (normelatonin), and then to melatonin, the body's principal sleep-regulating hormone and a powerful antioxidant.