“Serious safety concerns”: Scientists call for better regulation on muscimol-containing magic mushroom

12 Jun 2024 --- US-based researchers warn that the unregulated sales of Amanita muscaria, an increasingly popular “magic mushroom,” endanger public health. The compound muscimol and its biosynthetic precursor ibotenic acid have psychotropic effects. Still, these can also be more toxic than fentanyl, cocaine and PCP (phencyclidine), according to a review of mouse studies.

In their analysis of the mushroom’s history, availability, safety and legal status, the authors call for improved regulation. They assert, “Amanita muscaria products have been marketed with health-related claims — often by vague references to clinical studies reporting mitigation of anxiety, depression and other conditions.”

Although such claims violate regulations of the US Food and Drug Administration (FDA), the authors note that the organization’s limited resources may be why it has not initiated enforcement actions on these products. 

“There is a lot of interest in the therapeutic potential for psilocybin, and for good reason. But at the same time, a growing industry may be trying to capitalize on this interest by marketing other mushrooms,” says Dr. Eric Leas, assistant professor at the University of California in San Diego, US, and the paper’s senior author.

“For example, some manufacturers are calling Amanita muscaria products ‘magic mushroom gummies’ and not disclosing what mushroom they contain, or not making it clear Amanita muscaria is a different mushroom than psilocybin and has essentially no clinical evidence supporting its use as a therapy.” 

New legislation 
The review, published in the American Journal of Preventive Medicine, argues that lacking federal regulation on the mushroom may enable false marketing. 

The authors note that, unlike psilocybin, Amanita muscaria is not listed on a Controlled Substances list in the US, except for the state of Louisiana. Psilocybin continues to be a Schedule 1 controlled substance and is only allowed for the use of clinical trials after the FDA loosened restrictions in 2023. 

They add that federal and state regulators need to clearly decide whether it is legal to commercially manufacture and distribute products containing Amanita muscaria and muscimol. 

If yes, they call for reference standards and analytical chemistry methods to guide “appropriate testing of products to ensure accurate labeling for content to ensure consistent potency and absence of other toxins.” 

The review authors stress that Amanita muscaria is different from psilocybin and has essentially no clinical supporting evidence.Moreover, they note that regulatory standards are needed on age restrictions, childproofing, maximum doses and restrictions on marketing that appeals to children. 

“We have found that many manufacturers use supplement labeling, including ‘Supplement Facts’ panels,” adds Leas. “However, there is a process for bringing a supplement to market that involves presenting safety data and filing an application, and we cannot find any evidence that any of these manufacturers have gone through this process, and this makes the current products sold in this manner illegal.”

“In my view, if a manufacturer wanted to develop a dietary supplement from Amanita muscaria, the application probably would not be approved because of muscimol and ibotenic acids’ inherent risks,” he underscores. “But right now it is the ‘Wild West,’ and companies are profiting from delayed enforcement while putting consumers at risk.”

Psilocybin vs. muscimol
The authors also call on mental health professionals to help their patients distinguish between psilocybin, which is studied for its potential to treat depression, and Amanita muscaria, which has a higher toxicity and is not supported by clinical evidence. 

Emerging clinical research on psilocybin’s safety and efficacy has likely sparked an interest in Amanita muscaria, with products such as gummies and vapes containing the mushroom and isolated muscimol entering the market in recent years. 

Similar to psilocybin-containing mushrooms, Amanita muscaria has psychotropic effects, such as a feeling of weightlessness, visual and auditory hypersensitivity, space distortion, unawareness of time and colored hallucinations. 

However, psilocybin is an antidepressant, while Amanita muscaria is a depressant. Psilocybin binds to serotonin receptors to activate a neural pathway that mediates happiness and optimism. Amanita muscaria suppresses the central nervous system, much like alcohol and benzodiazepines. 

“There may be some pharmaceutical potential to Amanita muscaria, but muscimol does not have the same effects on the body as psilocybin, so it probably would not have the same treatment applications if it ever went through drug development,” cautions Leas. 

“For this reason, it is misleading not to distinguish between muscimol and psilocybin clearly. If someone is consenting to a psychedelic experience, they have a right to know what substance they are taking and receive accurate information about its potential health benefits and health risks.”

By Jolanda van Hal