Psilocybin mushrooms are going mainstream, but scientific research and regulation lag behind

Amid a , public interest in psilocybin – or , as they’ve long been known – is surging.

One study found that rates of psilocybin use from 2019 to 2023, and 188% among those over age 30. This amounts to more than 5 million adults using psilocybin in 2023 alone. And those numbers are rising: A study published in early 2026 found that about 11 million adults in the United States .

In many ways, the growing scientific and public interest in psilocybin mirrors the early days of . Much like how cannabis commercialization quickly outpaced the development of , the and are moving faster than the science and regulations needed to ensure it is used safely.

We are who have spent more than a decade studying the many new, high-THC cannabis products that have .

Now, we similarly aim to bridge the gap between public enthusiasm for psilocybin and the limited scientific evidence available about . Currently, this type of real-world data on the effects of psilocybin mushrooms is almost nonexistent.

How do psilocybin mushrooms work?

is a , which means that it has very low activity until the body converts it into . Psilocin is the compound primarily responsible for the psychoactive effects of psilocybin mushrooms.

Psilocin resembles the chemical messenger , which is involved in regulating a range of physiological and psychological functions, including and . As a result, when psilocin binds to serotonin receptors, it alters how people think, feel and experience the world.

Importantly, research suggests that psilocin also alters the , referred to as . This process likely underlies the profound and sometimes long-lasting effects psilocybin mushrooms can have on thoughts, emotions and perception.

Psilocybin mushrooms contain numerous other compounds, , such as baeocystin, norbaeocystin and aeruginascin. Research on rodents shows that mushrooms containing these compounds may elicit than psilocybin alone.

But very little is known about how these other tryptamines affect humans. This is because federal regulations require researchers to use an isolated, synthetic version of psilocybin in clinical studies rather than the entire mushroom.

Thus, the testing psilocybin as a treatment for various mental health conditions use synthetic psilocybin that does not contain these other tryptamines.

Psilocybin mushrooms sit in a legal gray area

Psilocybin is than ever before.

In 2019, Denver, Colorado, became the first American city to . This means that possession becomes the lowest law enforcement priority and criminal penalties are reduced or eliminated, but it does not fully legalize them.

Over the next two years, including Oakland and Santa Cruz, California; Seattle, Washington; and Detroit, Michigan, followed suit. In 2020, Oregon legalized psilocybin for supervised use in licensed settings, and Colorado did the same in 2022. These legal, supervised-use programs allow access to psilocybin mushrooms in regulated environments without a prescription.

Even for people living outside those states and cities, the barriers to accessing psilocybin mushrooms are low. With a quick Google search and around US$35, anyone can legally purchase kits containing the materials needed to grow psilocybin-containing mushrooms. These kits are legal to buy and sell because they contain only mushroom spores, which are tiny reproductive cells from which mushrooms grow. Once these spores begin growing into mushrooms, they can produce psilocybin, making the mushrooms a federal Schedule 1 substance.

Because psilocybin mushrooms exist in this legal gray area and are governed by different rules across states, psilocybin mushrooms are essentially unregulated across most of the U.S.

As a result, consumers lack reliable information about what their mushrooms contain, how much they should take and how to use them safely.

Psilocybin potency is increasing in the US

Much like the cannabis industry, which has seen a steady increase in , the psilocybin mushroom market is experiencing rapid growth.

For instance, are now available and increasingly popular.

In addition, selective cultivation practices are being used by individual and commercial growers to systematically increase the amount of psilocybin contained in their mushroom strains. For example, the , a community contest intended to identify the best mushroom strains, has shown wide variability in psilocybin content across samples.

Researchers are identifying a in scientific studies of psychedelic mushrooms from around the world.

Potential harms of psilocybin

Despite psilocybin’s therapeutic promise, it also carries risks. Psilocybin can cause .

Less commonly, some people experience , , , or .

Another serious potential side effect of psychedelic drugs is what’s known as . It involves similar to those experienced while directly under the influence of psilocybin, which can persist for weeks, months or years, even once the psilocybin has left the body.

Harms are more likely when people take high doses.

As mushroom potency increases without market regulation, consumers may inadvertently ingest more psilocybin than intended, increasing the risk of harm. Without sufficient research on modern psilocybin products, consumers have little guidance on how to reduce potential harms.

Next steps in research and regulation

Studying psilocybin in the real world requires creative research approaches.

Our team hopes to work within federal restrictions to study people using their own psilocybin mushroom products at home, while providing real-time data to our research team using app-based surveys.

using state-of-the-art measurement techniques can aid researchers like us by providing information about the potency of the mushroom products that people are using.

While ongoing clinical trials provide important data about the , real-world data is needed to understand how modern psilocybin mushrooms are used and experienced by consumers.

These insights matter not only for scientists and policymakers but for the growing number of people trying psilocybin mushrooms for relief, self-improvement or out of curiosity. In a largely unregulated market, and with few clear guidelines on safe use, consumers are left to simply figure it out on their own.