Ibotenic Acid: Compound Guide

Poisoning first. Ibotenic acid is one of the two main active components of Amanita muscaria and A. pantherina poisoning. A published report called ingestion of A. muscaria "not benign": it described one death and a case needing a breathing tube. [1] If someone has eaten one of these mushrooms, or a product claiming to contain Amanita, call 911 or US Poison Help at 1-800-222-1222 now. Do not wait for symptoms to settle. See poisoning: what to do first and plant and mushroom poisoning. This page gives no amounts, preparation or identification help.

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

What ibotenic acid is

Ibotenic acid is an amino-acid-like isoxazole compound that acts as an agonist (activator) at glutamate receptors, including NMDA and metabotropic glutamate receptors. Glutamate is the brain's main excitatory messenger. [2] It is related to muscimol but has a different action: muscimol is a potent agonist at GABA receptors, the brain's main inhibitory system. [2] Their main actions are on glutamate and GABA systems, not on the serotonin 5-HT2A receptors that NIDA says classic psychedelics such as psilocybin and LSD mainly act on. [3] Do not mix up ibotenic acid, muscimol, muscarine and psilocybin; they are separate chemicals with separate effects. See muscimol and psilocybin.

Ibotenic acid can lose a carbon dioxide group (decarboxylation) and become muscimol, so how much of each is present depends on the material and how it has been handled. [2] This page does not describe handling.

Where it comes from

Amanita muscaria (L.) Lam. (fly agaric) and Amanita pantherina (DC.) Krombh. (panther cap) are accepted names in GBIF. [4] A review identifies these two as the main species behind the "pantherina" poisoning syndrome, characterized by central nervous system dysfunction, and notes that other substances probably contribute too. [5] See the mushroom profiles Amanita muscaria and Amanita pantherina. Content differs between species and tissues and changes with handling. A 2026 review warns that comparing studies is limited by differences in sampling and analytical methods, so there is no reliable "typical" ibotenic acid content. [2]

Toxicology: what has been reported

• Two patterns. Poison-center data from 32 A. muscaria and 17 A. pantherina cases found A. muscaria patients were more often confused (26 of 32) and agitated (20 of 32), while A. pantherina patients were more often comatose (5 of 17 versus 2 of 32). The authors link this to A. muscaria having more excitatory ibotenic acid and less depressant muscimol. [6]
• US poison-center series. Of 34 cases over 2002 to 2016, 25 were symptomatic, and all but one developed symptoms within 6 hours. Five patients were intubated and no deaths were reported. A. pantherina ingestions were more often symptomatic than A. muscaria. [7]
• Severe outcomes. One man died 9 days after cardiopulmonary arrest; a 75-year-old needed a breathing tube and recovered. [1] A case report from a Swiss hospital describes a patient who fell into a coma after accidental poisoning and was discharged on the fourth day. [8]
• Older adults. A 2025 report of two elderly spouses describes profound nervous-system depression with cholinergic features, needing atropine and intensive care; both recovered. [9]
• Children. In the US series, some accidental pediatric ingestions were symptomatic. A 3-year-old who ate A. pantherina needed intubation and a 3-day ICU stay. [7]
• Limits. These are case reports and poison-center series. They show serious outcomes happen but not how often, and they cannot show what any one mushroom or product contains. Label: evidence of harm.

Research use versus human health

Ibotenate is used in animal brain-injury models: researchers have induced brain lesions in newborn mice with glutamatergic agonists including ibotenate. [10] Label: preclinical. This does not show what happens in people who eat a mushroom. A review of fungal hallucinogens (psilocin, ibotenic acid and muscimol) says that despite their well-documented neurotoxicity they gained a reputation of being safe, and that scientific efforts to find medical uses for them are highly controversial. [11] Proper evidence not found for a human treatment trial of ibotenic acid.

Regulatory status (not legal advice; laws change)

• US food: the FDA said in December 2024 that A. muscaria, its extracts and constituents including ibotenic acid, muscimol and muscarine are not authorized as ingredients in conventional food and may be harmful. [12]
• US controlled-substance lists: we did not find ibotenic acid named in the Schedule I list in 21 CFR 1308.11 (read 2026-10-22). [13]
• UK: we did not find it named in Schedule 2 of the Misuse of Drugs Act 1971 (read 2026-10-22). [14]
• Other countries and US states: not verified. See legal status by country.

Products and labels

In a 2025 test of eight mushroom gummies from Portland, Oregon shops, neither ibotenic acid nor muscimol was found in the two claiming Amanita extract; those products contained psilocin and other tryptamines. The authors concluded labeling was overall inaccurate. [15] Treat any Amanita content claim as a marketing claim. See unverified mushroom gummies and poisoning and misidentification.

Pregnancy and medicines

Proper evidence not found on ibotenic acid in pregnancy or on medicine interactions in the sources we checked. See pregnancy and breastfeeding and talk with a clinician.