Amanita muscaria, commonly called fly agaric or less often fly mushroom, is a basidiomycete mushroom of the genus Amanita.
The original white-spotted red toadstool, it is one of the most recognizable mushrooms and is widely encountered in popular culture.
Though it is generally considered poisonous, Amanita muscaria is otherwise famed for its hallucinogenic properties, which had a religious significance in Siberian culture and possibly ancient India and Scandinavia.
Since mediaeval times it has been used as an insecticide, from where it derives its name.
Consuming more than about one gram of Amanita muscaria can cause nausea and a number of other effects, depending on dosage, ranging from twitching to drowsiness, cholinergic effects (lower blood pressure, increase sweat and saliva), visual distortions, mood changes, euphoria, relaxation, and hallucinations.
In near-fatal doses it causes swollen features and delirium, characterised by bouts of marked agitation followed by periods of quiet hallucination.
Effects appear after around 60 minutes and typically peak within three hours, but certain effects can last for up to ten hours.
The effect is highly variable and individuals can react quite differently to the same dose.
In the United States, any sales of Amanita muscaria for human ingestion are regulated by the FDA.