This question comes up more often than you might expect, especially among people who like to dig a little deeper before trying anything new. Psilocybin gets talked about a lot for mood and mental health, but seizures sound serious, and they are. So let’s slow this down and explain what science actually says, in plain language, without panic or hype.
First, What Is a Seizure?
A seizure happens when there is a sudden burst of unusual electrical activity in the brain. This can cause shaking, confusion, loss of awareness, or changes in movement or sensation. Some people have epilepsy, which means they are more likely to have seizures. Others may never experience one in their life.
So when we ask if psilocybin can cause seizures, we also have to ask who we are talking about.
What Research Shows in Healthy People
Large reviews of psychedelic studies give us a helpful starting point. Researchers who looked at decades of clinical trials found that seizures are very rare in healthy participants given psilocybin under controlled conditions.
A major review published in JAMA Psychiatry looked at adverse events across many psychedelic studies. The authors reported that serious neurological events, including seizures, were uncommon and not seen as a regular risk in people without a seizure disorder.
In simple terms, when healthy volunteers took psilocybin in research settings, seizures were not something researchers expected or routinely observed.
What About People With Epilepsy?
This is where things change.
A scoping review published in the journal Seizure looked specifically at whether classic psychedelics might increase seizure risk. The takeaway was cautious. There is no strong evidence that psilocybin causes seizures in the general population, but people with epilepsy or a history of seizures may be more vulnerable.
There are also individual case reports, including one published in Frontiers in Neurology, where seizures occurred in a person with epilepsy after psychedelic use. These reports do not prove psilocybin directly causes seizures, but they do show that it may lower the seizure threshold in people who already have a neurological condition.
Put simply, psilocybin does not appear to create seizures out of nowhere, but it may increase risk in people who already have one.
Why Might Psilocybin Affect Seizure Risk?
Psilocybin works by activating serotonin receptors in the brain. These receptors help regulate mood, perception, and brain signaling. In most people, this does not cause problems. But in brains that already have unstable electrical activity, even small changes in signaling can sometimes matter.
That does not mean psilocybin is dangerous by default. It just means the brain matters more than the substance.
Important Context That Often Gets Missed
Here’s something that stood out to me when reading the research. Many reported seizure cases involved other factors, like lack of sleep, stress, or additional substances. In clinical trials, where those variables are tightly controlled, seizures remain extremely rare.
That contrast tells us something important. Context matters.
Summary
Psilocybin does not appear to cause seizures in healthy people, based on decades of clinical research. Large reviews show seizures are rare and not a common adverse effect. However, people with epilepsy or a history of seizures may face increased risk, and that risk should not be brushed aside.
The science points to a clear line: low concern for the general population, higher caution for those with existing neurological conditions.
Sources
Seizure – Do classic psychedelics increase the risk of seizures? A scoping review
Frontiers in Neurology – Case report: Psychedelic-induced seizures in a person with epilepsy
JAMA Psychiatry – Adverse Events in Studies of Classic Psychedelics