Few areas of medicine have changed as quickly as psychedelic research. Psilocybin has now passed two large phase 3 trials for treatment resistant depression, MDMA has been studied for PTSD, and an LSD-based medicine has reported positive phase 3 results for anxiety and depression. None of them is approved by the FDA yet, which means that for most people, a clinical trial is the only legal way to receive these treatments under medical care in the United States. This guide explains, in plain language, what is being studied, where each medicine stands, what taking part in a study really looks like, how participants are selected, and how to find a trial. One point to keep in mind from the start: these studies are medical research for people with specific conditions, carried out under close supervision.
Living with depression, PTSD, or addiction?
Clinical trials are testing new treatments, including psilocybin and other psychedelic medicines, under close medical supervision.
What psychedelic medicines are being studied
Psilocybin. The most advanced. It is being studied mainly for depression, especially depression that has not responded to standard treatment, and also for alcohol and methamphetamine use disorders, anxiety, and distress at the end of life. In the US alone, around 88 psilocybin studies are currently recruiting or about to start.
MDMA. Studied mainly for post traumatic stress disorder (PTSD), combined with psychotherapy. About 20 MDMA studies are recruiting in the US, including research in veterans and other groups.
LSD. An LSD-based medicine reported positive phase 3 results in 2026 for both depression and generalized anxiety disorder, with more phase 3 trials still underway.
Ketamine. Not a classic psychedelic, but related. A ketamine based nasal spray, esketamine (Spravato), has been FDA approved for treatment resistant depression since 2019, and ketamine itself is being studied for depression, suicidal thoughts, and other conditions.
Where FDA approval stands
Psilocybin is closest. A company called Compass Pathways reported positive results from its first phase 3 trial in treatment resistant depression in June 2025 and from a second phase 3 trial in February 2026, and is submitting its application to the FDA in stages. Even if approved, psilocybin would also need to be moved out of Schedule I, the most restrictive drug category, before it could be prescribed. MDMA took a step back: in August 2024 the FDA declined to approve MDMA assisted therapy for PTSD and asked for an additional phase 3 trial. Part of the challenge for all of these medicines is that participants can usually tell whether they received the active drug, which makes the standard "blinded" design of clinical trials harder.
Our guide explains how double blind studies work.
A few states, such as Oregon and Colorado, have created regulated programs for supervised psilocybin use, but these are not FDA approved medical treatment.
What taking part in a psychedelic study involves
Psychedelic trials look different from most drug studies, because the medicine is given in a controlled setting with trained staff present the whole time. A typical study follows a similar path:
Screening. Interviews, questionnaires, a medical check, and often heart tests, to confirm the study is a safe fit.
Preparation. Several sessions with a therapist or facilitator before the dosing day, to explain what to expect and build trust.
Dosing day. The medicine is taken in a comfortable room at the study site, under continuous supervision. Effects of psilocybin usually last several hours, and participants do not drive home afterward.
Integration. Follow up sessions to talk through the experience and track how symptoms change over the following weeks and months.
Some participants receive the study medicine, while others receive a placebo or a very low dose for comparison; our guide explains how placebo controlled trials work.
Who usually takes part
Each study defines its own criteria, usually built around a specific diagnosis, such as treatment resistant depression, PTSD, or an alcohol use disorder, along with an age range and overall health. Because these medicines affect the mind and the heart, studies typically screen carefully: people with a personal or family history of psychosis or bipolar disorder, certain heart conditions, or recent psychedelic use are often not eligible, and many studies ask participants to taper off antidepressants beforehand under a doctor's supervision, since some of them interact with psychedelics. These rules exist to protect participants and to make the results reliable.
Our guide explains how eligibility criteria work.
Safety, and how to recognize a real study
In clinical trials, psychedelics are given under medical supervision with screening and follow up, which is very different from using them on your own. Common short term effects include anxiety during the session, nausea, headache, and changes in blood pressure and heart rate, and the long term safety picture is still being studied, which is exactly why trials exist. A genuine clinical trial is reviewed by an ethics board, is registered on ClinicalTrials.gov, and never charges participants to join. Be cautious of "retreats" or programs that describe themselves as research but ask for payment.
How to find a psychedelic clinical trial
AllClinicalTrials.com lists mental health and addiction studies recruiting across the US and Canada, including studies of psilocybin, MDMA, and other new treatments, and you can filter by location. Start with our depression, PTSD, anxiety, alcohol use disorder, and methamphetamine use disorder pages. The application takes about 5 minutes: you answer questions about your diagnosis, past treatments, and current medicines, and if a study near you looks like a match, the research team contacts you. Nothing is decided until you have gone through informed consent, and participation is voluntary at every step.
If standard antidepressants have not helped you, our guide on what to do when depression medication is not enough covers the other options too.
Three things to have ready: your diagnosis and how long you have had it, the treatments and medicines you have tried, and any history of psychosis or bipolar disorder in you or your close family.
Common questions
Are psilocybin clinical trials legal? Yes. Clinical trials have special federal approval to study psilocybin, even though it remains a Schedule I substance. A trial is the main legal way to receive it under medical care in most of the US.
Is psilocybin FDA approved? Not yet. Psilocybin has completed two positive phase 3 trials for treatment resistant depression, and an application is being submitted to the FDA. It would also need to be rescheduled before it could be prescribed.
Why was MDMA therapy not approved? In August 2024 the FDA declined to approve MDMA assisted therapy for PTSD and requested an additional phase 3 trial, citing questions about how the studies were designed and the strength of the evidence.
What happens on a psilocybin dosing day? You take a measured dose in a comfortable room at the study site, with trained staff present the whole time. Effects usually last several hours, and you do not drive home afterward.
Do I have to stop my antidepressant to join? Many psilocybin studies ask participants to taper off certain antidepressants beforehand, because they can interact. This is always done gradually and under medical supervision, never on your own.
Will I definitely get psilocybin in a trial? Not necessarily. Many studies compare the medicine with a placebo or a very low dose, and neither you nor the staff may know which you receive until the study ends.
Are psychedelic trials safe? They are run with screening, close supervision, and follow up, and are reviewed by an ethics board. Short term effects such as anxiety or nausea are common, and long term safety is still being studied.
Do psychedelic trial participants get paid? Some studies offer compensation for time and travel, and study related care is typically provided at no cost to participants. Compensation varies by trial and is always described during the informed consent process before you agree to anything.