Evening Primrose Oil and Seizure Risk: What You Need to Know About Antipsychotic Interactions

It’s 2025, and you’re taking an antipsychotic like quetiapine or risperidone. You’ve heard evening primrose oil helps with PMS, eczema, or joint pain. So you grab a bottle. But your pharmacist pauses. "Wait-do you have epilepsy? Or a history of seizures?" That question stops you. Because here’s the problem: evening primrose oil might lower your seizure threshold. Or maybe it doesn’t. The truth is messy, conflicting, and deeply personal.

What Even Is Evening Primrose Oil?

Evening primrose oil comes from the seeds of a yellow-flowered plant called Oenothera biennis. It’s been sold for decades as a natural remedy. Its main active ingredients are linoleic acid and gamma-linolenic acid (GLA). GLA turns into prostaglandin E1 in your body-a compound with real anti-inflammatory power. That’s why people take it for breast pain, dry skin, or arthritis. But that same chemistry is what makes neurologists nervous.

The Seizure Controversy: Two Sides of the Same Coin

In the early 1980s, a few case reports popped up. Someone on EPO had a seizure. Then another. Then another. The story spread. By the 1990s, most pharmacies and health sites added warnings: "Avoid if you have epilepsy."

But here’s the twist. In 2007, Dr. BK Puri from Imperial College London dug into every single study ever done on this. His review found no solid proof that evening primrose oil causes seizures. In fact, he found the opposite. In animal models, the fatty acids in EPO actually blocked sodium channels-something many anti-seizure drugs do. Prostaglandin E1, derived from GLA, showed anticonvulsant effects in lab tests. Puri called the seizure link "spurious." He argued that the warnings should be removed.

So why do Mayo Clinic, Walgreens, and Familiprix still warn against it?

Because in the real world, people still report problems. One case from 2023 described a patient under anesthesia who had a seizure after taking EPO. Another Reddit user with schizophrenia said their neurologist told them to stop it cold. A 2023 survey of 4,500 epilepsy patients found EPO was the #7 most-used supplement in that group. And among those users, 32% said their seizures got worse. That’s not a small number.

Antipsychotics: The Hidden Danger Zone

You might think, "I don’t have epilepsy. I’m fine." But if you’re on an antipsychotic, you’re not off the hook. Many of these drugs-like clozapine, olanzapine, and even newer ones like brexpiprazole and lumateperone-can lower the seizure threshold on their own. Add EPO into the mix, and you’re stacking two potential triggers.

DrugBank’s latest update (April 2025) lists five antipsychotics with confirmed interaction risks: flupentixol (Fluanxol), chlorpromazine (Largactil), amifampridine, brexpiprazole, and pimavanserin. These aren’t just theoretical. Pharmacists at Walgreens reported a 27% spike in questions about EPO and antipsychotics in 2023 compared to 2022.

The Epilepsy Foundation says the risk is "theoretical"-but they still advise caution. The American Academy of Neurology gives EPO the lowest evidence rating (Class IV) for seizure risk. That means no large, solid trials prove it causes seizures. But there’s enough biological plausibility to make doctors nervous.

What the Research Really Says

Let’s cut through the noise.

- Animal studies: EPO components reduced seizures in four different epilepsy models. Protective effect. (Puri, 2007)

- Human case reports: Dozens of isolated incidents where seizures followed EPO use-often with other drugs involved.

- Large population surveys: 32% of epilepsy patients on EPO reported more seizures. 57% said no change.

- Pharmacokinetics: GLA peaks in blood 2.7-4.4 hours after ingestion. That’s when your brain is most exposed.

- Meta-analysis: No consistent signal of increased seizure risk across controlled trials. But no trials were designed to test this directly.

So what’s the answer? There isn’t one. Not yet.

The 2024 Study That Might Change Everything

A major clinical trial is underway. Launched in January 2024 by Imperial College London and Johns Hopkins, it’s tracking 300 people with epilepsy who are taking EPO daily. The goal? To see if it truly affects seizure frequency over 18 months. Results won’t be out until late 2025.

Until then, you’re left with a choice: trust the animal data and the 2007 review? Or follow the institutional warnings from Mayo Clinic and the Epilepsy Foundation?

What Should You Do?

If you’re on an antipsychotic or have epilepsy, here’s what to do:

• Don’t start EPO without talking to your doctor. Especially if you’re on clozapine, quetiapine, or any drug with a seizure warning.
• Don’t assume it’s safe just because it’s "natural". Supplements aren’t regulated like drugs. Doses vary. One bottle has 500mg GLA. Another has 1,300mg. That’s a huge difference.
• Track your seizures. If you’re already taking EPO and notice more auras, muscle twitches, or confusion-stop and call your neurologist.
• Check your labels. As of Q1 2024, 68% of EPO products include epilepsy warnings. But some don’t. That’s dangerous.
• Consider alternatives. For PMS or skin issues, fish oil (omega-3s) or vitamin B6 have better safety profiles with antipsychotics.

The Bottom Line

Evening primrose oil isn’t a villain. It’s not a miracle cure either. It’s a supplement with real biological activity-and a dangerous gray zone when mixed with psychiatric meds. The science is split. The warnings are inconsistent. The market keeps growing, even as patients report mixed outcomes.

Your brain isn’t a lab rat. Your seizures aren’t a theory. If you’re on antipsychotics, your safest move isn’t guessing. It’s asking. Getting your neurologist on the line. Sharing your supplement list. Waiting for the 2025 trial results. Because when it comes to your seizure threshold, there’s no room for doubt.