As outlined in our other blogs, Amanita muscaria is an iconic mushroom that is gaining interest for its potential medicinal and therapeutic uses. Amanita muscaria has three psychoactive compounds: muscimol, ibotenic acid, and small amounts of muscarine. As described in our blog on muscimol, muscimol is known for helping reduce anxiety and creating a sense of calm, euphoria, a dream-like state and drowsiness. But what about ibotenic acid?

This blog explores ibotenic acid, which is actually the psychoactive compound found in the greatest quantities in Amanita muscaria. Ibotenic acid is a naturally occurring compound subject to much controversy. Quite often, ibotenic acid is simply converted into muscimol before ingesting Amanita muscaria through a process called decarboxylation. But what are the effects of ingesting Amanita muscaria without first decarbing it?

Ibotenic acid and conversion to muscimol in the digestive system

When someone eats Amanita muscaria mushrooms, the stomach acids in the digestive system work to convert the ibotenic acid into muscimol. In small doses and microdoses, the digestive system can generally convert ibotenic acid quite well. However, when Amanita muscaria are consumed in high doses, the body can’t immediately convert all the ibotenic acid into muscimol. This is especially true when eating fresh Amanita muscaria, which has much higher ratios of ibotenic acid to muscimol than properly dried or processed Amanita muscaria. But the bottom line is that while small amounts of ibotenic acid will be digested as muscimol, ingesting overly large doses of ibotenic acid can overwhelm the body and result in psychoactive and toxic effects. What are some of the possible effects and how does ibotenic acid affect the body and mind?

How ibotenic acid stimulates the brain and nervous system

Unlike muscimol, which calms the brain, ibotenic acid actually stimulates it. How? Ibotenic acid stimulates “glutamate,” a neurotransmitter that in turn stimulates the central nervous system and neurons in the brain. Think of glutamate as creating a bridge that helps span the tiny gap between the neurons in the brain. When nerve cells release more glutamate, the glutamate binds to specific “receptors” on the neuron (particularly the NMDA or N-methyl-D-asparate receptor) allowing the stimulation or excitement signals to be “received” more easily, amping up the neurons and central nervous system.

Note that glutamate is not inherently harmful in normal amounts. In fact, glutamate plays a crucial role in various brain functions, including learning, memory, and cognition. Not only that, glutamate is a natural component of many foods, and the body can usually effectively regulate its levels. In the food industry, glutamate may even be added as an ingredient. For example, monosodium glutamate (MSG) is a sodium salt of glutamic acid. Low-level and temporary stimulation of glutamate is thought by some researchers to help with memory, learning and even help to build new neural connections and pathways. However, like many things in life, glutamate can go from helpful to harmful when overdone. Overly large doses of glutamate (or glutamate stimulators like ibotenic acid) can be toxic due to prolonged and intense stimulation of the neurons. So, while glutamate is both a natural component found in food and essential for normal brain function, excessive levels can be harmful and even toxic.

Worldwide regulations reflect the evolving understanding of Amanita muscaria and ibotenic acid—including differences in views on safety and consumption. Countries like Australia and even the Netherlands ban the sale of Amanita muscaria entirely, yet Canada has classified Amanita muscaria as a “natural health product” used for “medicinal” purposes in both dried and fresh form. In the United States, Amanita muscaria are legal in every state except Louisianna; however, the Federal Food and Drug Administration has not approved Amanita muscaria for human consumption.

Physical and psychoactive effects of large doses of ibotenic acid

On a physical level, the negative effects of large doses of ibotenic acid can include nausea, stomach cramps, sweating, loss of balance, loss of coordination and involuntary movements—with a few cases of seizures reported when Amanita muscaria are accidentally consumed by children. When injected directly into the brain, ibotenic acid has resulted in lesions and a loss of neurons in rats.

On a psychoactive level, large doses of ibotenic acid can cause confusion, agitation, perceptual changes, disorientation, dizziness, delirium and dissociation or detachment from reality.

Dosage: Amanita muscaria, ibotenic acid and muscimol

As we discuss below, the amount of ibotenic acid and muscimol in Amanita muscaria can vary from mushroom to mushroom. This, and the potential negative effects of ibotenic acid, are why it's not recommended to ingest more than a microdose of 0.5-1.0 grams of dried Amanita muscaria--for example, the book “Microdosing with Amanita Muscaria” considers 1 gram to be a microdose.

Since both muscimol and ibotenic acid are present in Amanita muscaria, we will briefly cover both here. Different sources have different ranges for a psychoactive dose of these compounds but all agree that muscimol is more potent than ibotenic acid. For example:

• This article in Science Direct states the “psychoactive dose of muscimol and ibotenic acid is estimated to be at 6 mg and 30–60 mg, respectively.”
• According to another source, the psychoactive dose of muscimol is about 10-15 mg, while a psychoactive dose of ibotenic acid is estimated at 50-100 mg.
• This third article from Science Direct gives a 5-15 milligram range for a psychoactive dose of muscimol (and does not give a range for ibotenic acid).

Regardless of the differences, the sources point to muscimol being five to ten times stronger than ibotenic acid. The effects of both ibotenic acid and muscimol begin about 30 minutes after ingesting, peak at about two to three hours, and typically last six to eight hours. Note that when Amanita muscaria is consumed in large amounts where the digestive system cannot effectively convert the ibotenic acid to muscimol, it can not only result in the negative side effects described above, but the effects can also be erratic as the ibotenic acid stimulates the nervous system while the muscimol calms it, sometimes resulting in swings between calm and stimulation.

When it comes to determining the effects of Amanita muscaria, what adds complication is that the amount of ibotenic acid and muscimol can vary from one individual mushroom to another, each person may react to these compounds differently, and each person’s digestive system may more or less efficiently convert ibotenic acid to muscimol. Additionally, the studies cited above do not give information about how ibotenic acid and muscimol interact, that is, what is the psychoactive dose when an individual ingests both ibotenic acid and muscimol simultaneously at different levels?

How much ibotenic acid is in amanita muscaria?

So how much ibotenic acid is found in Amanita muscaria? It depends. Fresh and unprocessed Amanita muscaria have the highest levels of ibotenic acid, generally thought to average around a 9:1 ratio of ibotenic acid to muscimol. Properly drying Amanita muscaria caps is generally found to convert about 1/3rd of the ibotenic acid into muscimol—but this is significant because, for example, a fresh mushroom that has a 9:1 ratio of ibotenic acid to muscimol would have a 3:2 ratio after drying.

However, this ratio is a guideline and not a hard and fast rule as each individual mushroom will vary. For example, two lab tests of Wild Forest Herbs dried amanitas showed muscimol levels of about 1.1 mg per dried 1 gram of caps, but the ibotenic acid varied from 2.6 mg to 4.2 mg per 1 gram of dried caps. Further conversion of ibotenic acid into muscimol can be achieved by decarboxylation. If the caps were decarbed and the ibotenic acid was converted to muscimol, this would lead to ~3.7-5.3 mg of muscimol per gram of dried caps in the Wild Forest Herbs samples, but without decarbing, dosage and effects of amanita are more difficult to determine and control. For this reason, it’s common to decarb a large batch of amanita at one time and achieve an “averaging effect” across the batch—and then to still proceed with caution knowing there will be variation in the amount of muscimol and ibotenic acid from batch to batch. With dried Amanita, an average effect can be achieved by blending many mushrooms into a powder. 

Conclusion, Precautions and safety

Amanita muscaria mushrooms have been used for ritualistic or shamanic purposes by some cultures for thousands of years. Regardless, these mushrooms carry potential risks. Most medical and research studies focus on muscimol, given the potential toxic effects of ibotenic acid so researchers approach Amanita muscaria with caution and many recommend always decarbing Amanita muscaria, while others feel it is unnecessary when consumed in small amounts.

PLEASE NOTE: Wild Forest Herbs believes in sharing the growing scientific understanding of Amanita muscaria. However, our blogs are for educational and scientific study purposes only and nothing in these blogs should be taken as endorsing or recommending eating or ingesting Amanita muscaria. The Federal Food and Drug administration has not approved Amanita muscaria for human consumption.