Shrooms, or magic mushrooms, are a type of fungi that contains psilocybin. Psilocybin is a naturally occurring psychedelic compound that is responsible for the psychoactive effects of shrooms. When consumed, psilocybin is converted into psilocin, which is responsible for the hallucinations and other psychological effects of shrooms. The effects of shrooms typically begin within 30 minutes to an hour after ingestion and can last for several hours. The peak effects of shrooms are typically felt after 2 to 3 hours.