Muscimol: Compound Guide

Poisoning first. Eating Amanita muscaria, which contains muscimol and ibotenic acid, has caused coma, a need for a breathing tube, and at least one death in published reports. [1][2] If someone has eaten a wild mushroom, or a gummy or other product said to contain Amanita, call 911 or US Poison Help at 1-800-222-1222 right away. Do not wait for symptoms to pass. See plant and mushroom poisoning and poisoning: what to do first. This page gives no amounts or preparation steps, and it cannot help you identify a mushroom.

Evidence labels used here: approved medicine, insufficient evidence, preclinical (cells or animals only), evidence of harm, marketing claim. Where we looked and found nothing usable, we write "Proper evidence not found."

What muscimol is

Muscimol is a psychoactive isoxazole found in Amanita muscaria (the fly agaric) and related mushrooms. [3] It is structurally related to GABA, the brain's main inhibitory messenger, and acts as a GABA-A receptor agonist with high affinity. [4] That is a different target from classic psychedelics such as psilocybin and LSD, which NIDA says mainly act on serotonin 5-HT2A receptors. [5] Muscimol is not psilocybin, and the two should never be treated as interchangeable. See psilocybin for that compound.

The same mushroom also contains ibotenic acid, which is chemically related but acts on glutamate receptors instead. Ibotenic acid can lose a carbon dioxide group (decarboxylation) and become muscimol, so the balance of the two depends on how the material has been handled. [6] For the toxin, see ibotenic acid.

Source organism, compound and history

• Source: Amanita muscaria (L.) Lam. and A. pantherina (DC.) Krombh. are accepted names in GBIF. [7] A review ties the pantherina poisoning syndrome mainly to these two species, with ibotenic acid and muscimol as the active components. [8]
• History: muscimol use dates to Siberian shamanic cultures as an entheogen, per a 2024 chemistry review. [4] This site does not describe ceremonies. The review of the fly agaric says use of the mushroom began in ancient times and is connected with mysticism. [8]
• Research tool: muscimol was discovered in the early 1960s and is widely used to study GABA receptors; it was a lead compound for other GABA-acting agents. [3][4]

Content is variable and cannot be assumed

A 2026 review of ibotenic acid and muscimol in Amanita muscaria found variation between species and tissues, changes during handling, and cross-study comparisons limited by differences in sampling and analytical methods. It concludes that toxicological interpretation depends on total dose, preparation and individual susceptibility. [6] So there is no reliable "typical" muscimol content for a mushroom, extract or product, and a label figure is a marketing claim unless independently tested.

Regulatory status (not legal advice; laws change)

• Muscimol as an approved medicine: a 2024 review states it is not approved for clinical use. [4]
• US food: on 18 December 2024 the FDA told manufacturers that Amanita muscaria, its extracts, and muscimol, ibotenic acid and muscarine are not authorized as ingredients in conventional food, do not meet the generally recognized as safe standard, and may be harmful. The FDA also said it was evaluating their use in dietary supplements. [9]
• US controlled-substance lists: we did not find muscimol or Amanita muscaria named in the Schedule I list (21 CFR 1308.11), read 2026-10-22. [10]
• Other countries and US states: not verified. See legal status by country.

What research shows

• Treatment benefit in people: insufficient evidence. Proper evidence not found for a human treatment trial of muscimol. We searched PubMed for muscimol, Amanita and toxicology and found chemistry, pharmacology and poisoning reports.
• Pain and other uses: preclinical or early. The 2024 review says recent research suggests possible use in neuropathic pain and that other uses are being studied. It does not report an approved use. [4]
• Neuroprotection: a review calls opinions on muscimol analogs for neurodegenerative disease and cerebral ischemia "conflicting." [11]

Risks

• Poison-center data. A regional poison center reviewed 34 cases from 2002 to 2016. Of 25 symptomatic patients, all but one developed symptoms within 6 hours, five were intubated, and none died. Effects included stomach upset, nervous-system excitation and nervous-system depression. [12]
• Fatal and severe cases. A man who ate dried caps for their mind-altering effects had cardiopulmonary arrest and died 9 days later; a 75-year-old who accidentally ate a foraged cap needed a breathing tube and recovered. [1] Two elderly spouses had profound nervous-system depression needing intensive care and recovered. [13]
• Wild mushrooms. A Swiss case report notes that A. muscaria can be mistaken for edible species. [2]
• Edibles. In a 2025 test of eight psychoactive mushroom gummies from Portland, Oregon shops, neither muscimol nor ibotenic acid was found in the two products claiming Amanita extract. They contained psilocin and other tryptamines instead, and one product contained undisclosed THC. The authors concluded labeling was overall inaccurate. [14] This is eight products from one city, so it cannot show what other products contain.
• Children, pregnancy, medicines: the poison-center series included accidental pediatric ingestions, some symptomatic. [12] Proper evidence not found on pregnancy or medicine interactions. See pregnancy and breastfeeding.