Microdosing mushrooms, touted as therapeutic and embraced by numerous Hollywood stars like Miley Cyrus and Seth Rogan, has sparked a rise in harmful reactions.

This trend has been increasing over recent years, paralleling policy changes in certain regions and a surge in research exploring its potential benefits for enhancing mood and mental well-being.

Microdosing entails consuming minimal amounts of psychoactive mushrooms, notably less than a standard dose, insufficient to cause a ‘trip’ or psychedelic experience, but intended to enhance mood, creativity, focus, or productivity.

However, the key components in psychedelic mushrooms, psilocybin and psilocin, are deemed Schedule I substances by the FDA, rendering them illegal at both federal and state levels.

More recently, some states and local municipalities have begun the process of decriminalizing the possession of these mushrooms.

As mushrooms and psychedelics gain wider acceptance, a growing market for edible products has emerged. To satisfy this demand, producers are utilizing various types of mushrooms—including both psychoactive and non-psychoactive species—some of which may be more toxic.

Lately, non-hallucinogenic mushroom varieties are making their way to supermarket shelves, vape stores, and even gas stations, marketed with claims of enhancing cognitive function.

People can purchase a bag of gummies labeled nootropic – a term used to describe substances that claim to enhance mental ability and function, or ‘smart drugs’ that may actually contain toxic ingredients.

This is because key pieces of information can be missing for consumers to make informed decisions about which products to consume, and some have been found to contain toxic mushrooms or other undisclosed substances, leading to an uptick in complaints and hospitalizations.

Last year, health experts from the University of Virginia issued a warning after five people in the area – including a three-year-old child – were sickened from these products.

They tested five different brands of mushroom gummy products sold in Central Virginia gas stations and smoke shops.

Of those, three contained psilocybin or psilocin, three had listed Amanita mushrooms, while multiple products contained un-listed additives, including caffeine, ephedrine, mitragynine, and N,N-dimethyltryptamine (aka the psychedelic DMT). 

Meanwhile, data from the the National Poison Data System reveals that psilocybin-related calls more than tripled among teens ages 13 to 19 from 152 to 464 and more than doubled among adults ages 20 to 25 from 125 to 294 between 2018 and 2022.

However, I will point out that this doesn’t necessarily mean that there’s more toxicity, it’s probably correlated to higher usage levels. 

While nootropic products have potential to boost health, there can be little transparency surrounding many commercial mushroom products, which can have dangerous consequences.

The main psychoactive components of traditional ‘magic’ mushrooms, found in the genus Psilocybe, are psilocybin and psilocin. These two small molecules are alkaloids that activate receptors in the brain to trigger the main psychoactive effects of magic mushrooms.

Both psilocybin and psilocin have a high therapeutic index – meaning they are generally nontoxic in humans because the amount that must be ingested to be fatal or dangerous is more than 500 times the dose at which it has been shown to be therapeutically effective.

Therefore, psilocybin-containing mushrooms are generally considered to have a low potential for acute toxicity in humans, to the point where it is believed to be nearly impossible to achieve a toxic dose from oral consumption.

With the growth in popularity of psychedelic mushrooms, companies have been looking for ways to meet consumer demand.

And in some cases, this has meant finding mushrooms that do not contain psilocybin and are therefore not restricted by the FDA.

The result has been an increase in products that come without legal entanglements, which means there are products that can contain other types of mushrooms, including lions mane, chaga, reishi, maitake and a genus of mushrooms called Amanita, which can be hallucinogenic.

Amanita mushrooms are the quintessential white-flecked, red-capped toadstools – the stereotypical image of a mushroom.

These fungi contain very different compounds compared to the Psilocybe mushrooms, such as muscarine and ibotenic acid.

These compounds function differently in the brain and, while also capable of producing psychedelic experiences, are generally considered to be more toxic.

Nootropic and other mushroom products are often found as edibles, including chocolates and gummies.

However, there is little enforcement surrounding the ingredient labeling of such dietary supplements; products that have a proprietary blend of ingredients generally do not have to report individual ingredients to the species level.

This protects trade secrets regarding unique blends of ingredients, but it can also obscure the actual composition of some edible nootropic and microdosing products. And this can have dangerous consequences.

The explosion of nootropic mushroom products has led to a wide variety of products on the market that potentially contain wildly differing levels of mushrooms, many times containing blends of multiple mushroom species.

And with little reporting guidelines in effect, it can be hard to know exactly what you’re taking.

One case study in Virginia involved five people who were hospitalized after they ingested gummies from different nootropic brands that were labeled to contain muscarine, muscimol and ibotenic acid, all compounds found in Amanita mushrooms.

A follow-up analysis of locally available gummy brands that contained ‘mushroom nootropic’ ingredients revealed the presence of psilocybin, but also caffeine, the stimulant ephedrine and mitragynin, a potential painkiller found in Southeast Asian plant products like kratom. None of these ingredients were listed on the product label.

Therefore, the cocktail of mushrooms and substances that these people were exposed to was not necessarily reflected on the label at the time of purchase.

The increase in use of other, potentially toxic, mushrooms in over-the-counter products has been reflected in reported poisoning cases in the United States.

In 2016, out of more than 6,400 mushroom-related poisoning cases in the U.S., only 45 were Amanita mushrooms.

In the past few years since certain states began decriminalizing psilocybin, the U.S. has seen an increase in calls and reports to poison control centers of people feeling nauseous and experiencing vomiting, seizures, cardiovascular symptoms and other adverse effects after ingesting edible mushroom products such as chocolates and gummies.

 This prompted a multistate investigation beginning in 2023 that uncovered over 180 cases in 34 states of people who had ingested a particular brand of mushroom-based edibles, Diamond Shruumz.

A 2024 recall required that stores remove these products from their shelves.

And in late 2024, the FDA put out a letter to warn consumers and manufacturers of the dangers associated with Amanita mushrooms, saying they ‘do not meet the Generally Recognized As Safe, or GRAS, standard and that Amanita mushrooms are unapproved food additives.’

Despite this warning, such products are still available from producers.

Even when a product is labeled with the relevant ingredients, mushrooms are notoriously easy to misidentify when collected. Numerous mushroom species have similar shapes, colors and habits.

But, despite their visual similarities, these different mushrooms can have drastically different chemistry and toxicity.

This even plagues foragers of culinary mushrooms, with hundreds of emergency department visits due to fungal misidentification every year in the U.S.

There is little current regulation or oversight for species identification in dietary supplements or over-the-counter mushroom edible products, leaving consumers at the mercy of producers to accurately list all raw products and ingredients on the product label.

This article is adapted from The Conversation, a nonprofit news organization dedicated to sharing the knowledge of experts. It was written by Joshua Kellogg, an Assistant Professor of Natural Product Chemistry at Pennsylvania State University.