The use of psilocybin — the hallucinogenic compound found in “magic mushrooms” — has increased significantly in Denver and throughout the country, driving a spike in calls to national poison control centers, a study found.

Researchers from Denver Health’s Rocky Mountain Poison & Drug Safety Center and the University of Colorado Anschutz Medical Campus found that the use of psilocybin increased nationwide across all age groups, especially among adolescents and those over 30.

“We found that since 2019, the number of people using psilocybin has gone up sharply,” said Karilynn Rockhill, co-lead author of the study and a researcher at the Colorado School of Public Health, in a news release. “This seems to line up with when some U.S. states began to decriminalize or legalize it.”

In 2022, Colorado passed Proposition 122, which decriminalized the personal use of five psychedelic substances, including psilocybin, though the sale of psilocybin remains illegal. Colorado was the second state in the nation to decriminalize its use after Oregon.

The study, published on April 21 in the Annals of Internal Medicine, noted that adults who reported using psilocybin increased from 25 million people in 2019 to 31 million people in 2023. 

• Use among young adults (ages 18–29) increased by 44% from 1.2 million users in 2019 to 1.7 million in 2023.

• The rate for those 30 years and older increased by 188%, from 1.3 million in 2019 to 3.8 million in 2023.

• Use among 12th graders increased by 2.4% in 2023, but rose 53% over five years.

While the study only had official data through 2023, additional information being collected for 2024 is showing a continued rise, Dr. Andrew Monte, a professor of emergency medicine at the University of Colorado Anschutz Medical Campus in Aurora, told CNN.

The study also noted that, while only three instances of psilocybin exposure were documented nationwide by hospital emergency rooms and outpatient clinics from 2019 to 2023, there were marked increases in the number of calls to poison control centers. 

• There were 396 calls to poison control centers for psilocybin exposure in 2019 by adults. That number rose to 1,192 calls in 2023, an increase of 201%.

• The number of calls grew by 317%, from 130 in 2019 to 542 calls in 2023, for adolescents 12 to 17 years old.

• Poison control calls for children under 12 saw the biggest increase with 35 calls in 2019 rising to 288 calls in 2023, a 723% increase.

The “mismatch” between what hospitals report and the number of calls to poison control centers, according to Joshua Black, senior scientist at the Rocky Mountain Poison & Drug Safety Center, tells researchers that they’ve “lacked visibility into the real-world health impacts of psilocybin use.”

Locally, between March and December 2024, Colorado’s poison center was contacted 133 times for psychedelic exposure, a Denver Health statement said in January, adding that the ages for those calls ranged from 10 months to 90 years old.

Those kind of numbers worry Rachel O’Bryan, co-founder of One Chance to Grow Up, a nonprofit focused on youth use and unintended consequences resulting from state policy surrounding marijuana and other controlled substances.

“This study is very timely because we’ve only just begun the licensing of healing centers. So, now we have a baseline number that we will be able to track going forward,” O’Bryan told The Denver Gazette.

Colorado lawmakers want more data on ‘magic mushroom’ use

At the state Capitol, lawmakers said they want more data on psilocybin’s use. 

Senate Bill 25-297 is making its way through the legislative process. Under the bill, the Colorado Department of Public Health and Environment, Department of Revenue and Department of Regulatory Agencies would be required to collect information and data on the use of psilocybin therapy in the state, including negative health impacts, impacts on health care facilities, law enforcement incidents, and consumer protection claims against facilitators.

Data collection efforts would be funded by gifts, grants and donations from nonprofits and academic institutions, and all data would be stripped of any identifying information for security and privacy purposes. 

Adults over 21 years of age in Colorado may possess, cultivate and give away psilocybin-containing mushrooms, but are prohibited by law from selling them. They may also access psychedelic-assisted centers, where patrons can experience the effects of the mushrooms in a supervised environment. 

The licensing and regulation of “natural medicines” in Colorado falls under two state agencies: the Department of Revenue (DOR) and the Department of Regulatory Agencies (DORA). 

The Natural Medicine Division in the DOR licenses and regulates those businesses — clinics, cultivators, manufacturers, testing facilities, and their owners and employees. 

DORA licenses and regulates the facilitators of such services.

In March, DORA issued its first operational license for what’s called “psychedelic-assisted therapy” to The Center Origin at 1440 Blake St. in Denver. 

Some early research suggests potential with the use of psilocybin for the treatment of certain conditions, such as depression and anxiety, and the study found that people with mental health conditions or chronic pain were more likely to report using psilocybin. However, psilocybin has not been approved by the U.S. Food and Drug Administration for treatment.  

Critics insist that the substance is linked with suicide and accidental deaths, as well as associated with psychosis. Critics have also been pushing for strict oversight, arguing it is necessary because psychedelics are being promoted and “normalized on social media in the same way that marijuana has been for the past decade.”

Psilocybin-infused products make their way into market

The growing interest in the legal consumption of “magic mushrooms” and recent decriminalization have fueled a wave of offerings of psilocybin-infused products.

Mushrooms, tablets, gummies, chocolates and others are being peddled via the internet.

“This whole idea that (psilocybin) is not allowed to be commercialized is only as good as whether the state is willing to enforce that limit,” O’Bryan said. “So, we see signs and ads and online (shops) selling this product and selling it in candy form.”

While personal use and the sharing of psilocybin without compensation is permitted, the sale of psilocybin is a criminal offense.

According to the Colorado Department of Revenue, nothing in the Natural Medicine Code limits police departments, sheriffs, or other state or local law enforcement agencies from investigating psilocybin business licensees, owners or substance handlers for unlawful activity.

“As we have stood up the regulatory program and began accepting applications for licensed natural medicine businesses, the Department of Revenue’s Natural Medicine Division has issued cease and desist orders when we identify blatant violations of the law to help educate the public,” Natural Medicine Division Communications Manager Heather Draper told The Denver Gazette. “However, the DOR’s authority to take action is against licensed operators. Enforcement of the criminal code is the responsibility of local law enforcement.”

Since 2023, Colorado’s Department of Revenue has issued four cease and desist letters to businesses engaged in the commercial sale of psilocybin mushrooms.

Operating in gray areas

As the state continues to roll out its licensing programs, some in Denver continue to do business in what many see as a gray area.

Darren Lyman operates what he calls a psilocybin “harm reduction support center” on West Eighth Street, near Santa Fe Drive in Denver. 

He said his facility aims to educate clients about the use and risks of psilocybin, offering support before, during and after a psychedelic experience.

That support comes in the form of a consultation about the psychedelic experience itself, what to expect, the benefits of psilocybin use, as well as potential risks, including interaction with other drugs, medicine and alcohol.

Lyman charges for the consultation and any requested support, but the psilocybin and psilocybin-based products he has are given to clients as gifts.

Under the state’s new law, facilities may store specified amounts of dried mushrooms on their premises, provided they are stored in a locked facility and not commercialized. 

Licensed facilitators in Colorado who are authorized by the state to supervise sessions may provide psilocybin for their clients. However, they are not permitted to sell it to them or permit clients to take it home.

“I have multiple levels (of support) like a micro-dosing guide that includes how to dose out all of the benefits, tips and techniques for emotional regulation. We teach that also in the session,” he said. 

Lyman insists he operates legally. He said his facility is not a dispensary and he does not sell products to his clients.

He said he has clients from as far away as the United Kingdom and that Colorado law supports “harm reduction” services, such as his, because they foster safe and responsible psilocybin use. 

In November 2023, the Colorado Division of Revenue issued a cease and desist order to Lyman, citing “unlicensed and unlawful activity” based on print advertisements he ran which “included specific prices for psilocybin products.”

‘A problem and an opportunity’

Researchers agree that as interest continues to grow in the use of psilocybin, more attention needs to be directed to data and policy development.

“It’s important to collect (data) now because things are changing,” Black said. “I think it’s possible to go backward in time to understand what’s happening, and with the changes in policy and the increased availability, I think the general public needs to understand the best ways, the safest ways to use substances, as well as the potential health opportunities.”

Black added that having “the best, most accurate information” about psilocybin use helps individuals make healthy choices.

As public views continue to change, Black said psilocybin has grown to be the second most commonly used controlled substance, behind only cannabis, and so its prevalence is quite high relative to other drugs.

“I think it’s both a problem and an opportunity,” Black said. “I think there’s a lot of very interesting evidence in clinical trials showing that these drugs may have quite meaningful benefits for people who are suffering from mental health conditions or substance use. And so, going into the future, (we need to ensure) that we balance the benefits that come from a novel pharmacotherapy against the potential risks individuals may face if they’re using in unsafe ways.”