Before a BCSP study participant takes a capsule of psilocybin, researchers must prepare in ways unlike almost anything else in basic science research: navigating state and federal approvals, inspections by DEA (Drug Enforcement Administration) agents, and guiding the volunteer study participants through their expectations of the experience and what kind of support they could need. Clinical trials are central to the BCSP’s mission—but unlike in therapeutic trials, the goal isn’t to test novel treatments or new psychiatric drugs. “We’re doing basic investigations into the neuroscience of psychedelics, rather than doing drug development for treatment of mental health disorders,” says faculty director Michael Silver. “We hope that our research will lead to a broader understanding of how psychedelics work in the brain and on the mind and that this foundational knowledge will eventually lead to better treatments.”

Even for experienced researchers, working with psychedelics can pose new challenges, from procuring Schedule I substances to guiding participants through potential psychoactive effects to appropriately documenting adverse events. 

How to get FDA and DEA approval

Depending on which federal Schedule a substance falls under, it may require additional steps for approval. Schedule II substances, like opioids, cocaine, and Adderall, are designated as having a high abuse potential but some medical use; they require strict storage security and registration with the DEA. Schedule I substances, including psychedelics, have been designated by the DEA as having no medical use and a high potential for abuse, so they require even higher levels of regulatory oversight.

Many psychedelic substances are Schedule I, which means that the BCSP’s psilocybin studies require additional steps: at UC Berkeley, human subjects research with psilocybin must be approved by the University’s institutional review board, the Regulatory Advisory Panel of California, the Food and Drug Administration, or FDA, and the DEA.

On September 14, the FDA held a public hearing to talk about the potential future therapeutic use of psychedelic drugs in supervised and supportive settings, which would require the rescheduling of psychedelics from Schedule I. Those opposed to rescheduling often argue that psychedelics have not yet been proven to have an acceptably low potential for abuse or addiction; other experts disagree. “Some of these substances are natural products that have been used as medicines for centuries,” says Silver. “The potential for abuse of some psychedelics is far less than some drugs that are typically considered to be medications in Western societies.”

Where do you store a Schedule I substance?

Once the trial has been approved by the FDA, researchers need to obtain the substance itself. “Because it’s an FDA-regulated clinical trial, it needs to be pharmaceutical grade,” explains Silver. “There are only a handful of viable suppliers that have clearance from the DEA.”

Once researchers have the substance, there are strict protocols to keep it secure. “We have very intense safes where the drug is stored, extensive logging and record-keeping, and 24/7 temperature monitoring. The DEA has sent agents to inspect our facility so the drug doesn’t get into the wrong hands,” says Silver, who is the official Schedule I DEA license holder for the BCSP’s human subjects research.

Preparing and dosing participants

It might be labor-intensive to obtain the federal agencies approvals for this research, but the current excitement about psychedelics research makes it easy to recruit participants. “We literally have hundreds of people on a wait list,” says Silver. “Some people are interested for pro-social reasons, and some just because they think it would be cool to have a psychedelic experience in a Berkeley lab, but recruitment has been a piece of cake.”

Preparing the participants for their research experience is largely the work of the BCSP’s clinical research coordinators, Michael Zadeh and Erin Vinson, and session monitors, physicians and licensed nurse practitioners who also stay with a participant during the dosing to provide support. The study’s protocol includes conversations between team members and participants about their preconceptions about psychedelics: if they’ve had negative or positive experiences in the past and what their expectations may be about the dosing. 

The preparatory conversations include setting intentions, understanding a patient’s current stressors in case they come up, and talking about techniques for grounding and self-awareness. These conversations are different from those in more typical clinical trials, because a psychedelic experience will likely be different than that of other drugs. “In a lot of drug trials, the goal is to quell some symptoms, to reduce problems that the participant has,” says Zadeh. “Psychedelic dosings aren’t usually as straightforward.”

In the pre-dosing conversations, BCSP staff also talk with participants about how they would like to be supported while experiencing the effects of psychedelics. Zadeh explains, “We ask them questions like, would you welcome session monitors to talk you through things that are coming up, or would you rather be left alone?” Session monitors are trained to provide psychological support and to attend to any adverse events during the study, including any need for psychological support should difficult thoughts or feelings arise.

Recording adverse events

During the session itself and in conversations in follow-up study visits, BCSP staff track the experiences of participants to learn how psychedelics affect the mind. That includes recording adverse events, which are defined as any untoward or unintended medical occurrence, including symptoms, experienced while a participant is undergoing a clinical trial. 

“Fundamentally, the purpose of adverse events is to better understand how drugs affect people, and to do it in a systematic way that can really be analyzed and doesn’t have bias to it,” says Alia Lilienstein, a research physician at the BCSP. 

It’s a common misconception that “adverse events” are necessarily negative. In fact, drugs can also have unintended positive side effects. For example, Viagra was initially developed as a medication for angina (cardiac chest pain). “It turned out it wasn’t helpful in their early clinical trials for chest pain for angina, but they noticed an interesting adverse event: men in the drug group were reporting spontaneous erections and men in the placebo group were not,” says Lilienstein. “It was enough of a difference that they decided to study it for erectile dysfunction.”

Positive adverse events can be cause for concern, which is part of why the FDA has issued guidance to report positive adverse events as well. As the FDA published in July 2026, “Some expected psychoactive effects such as euphoria, hallucinations and other perceptual distortions, and alterations in cognition should also be recorded as AEs for psychedelic drugs given their association with abuse potential, even if subjects do not describe these effects as adverse.”

To track adverse events, Lilienstein and other BCSP staff include participants’ spontaneous reports, in which they notify researchers within 48 hours of any change from their baseline health. “We counsel them about specific things that we’re trying to measure, but also that they should notify us about all events, even tripping off a curb or the common cold, because there’s always the chance that a drug will make some people more susceptible to the common cold,” says Lilienstein. 

But with psychedelic substances, adverse events are often far more subjective than the common cold. “When people experience love for family members, or self-compassion, should those be recorded as adverse events? What about awe or expansiveness or oneness?” asks Lilienstein. “Establishing a baseline can be really hard, but if anything happens that seems different than someone’s baseline, it’s worth reporting as an adverse event.”

A meaningful process

Although working with psychedelics can be more complicated for researchers compared to other substances, it can also be highly rewarding. “We learn a lot about our participants’ lives that isn’t necessarily standard for this kind of study,” says Zadeh. “For other trials, you don’t need to know about the challenging things they may or may not want to process, but it’s really important that these things are understood by our staff so that we can all remain sensitive and be supportive.” 

While that creates additional responsibilities, it’s also a privilege. “Even if it’s not the goal of the study to treat anyone for their problems, a lot of people come in really excited and curious about what insight the psychedelic might give them into themselves or the world, and I’ve seen a lot of people come out of the study feeling really positive,” says Zadeh. “It’s a joyful thing to be a part of.”