This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. Muscimol (also known as agarin or pantherine) is the principal psychoactive constituent of Amanita muscaria and related species of mushroom. Muscimol is a potent, selective agonist for the GABAA receptors and displays sedative-hypnotic and dissociative psychoactivity. This colorless or white solid is classified as an isoxazole.