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

If you’re taking antipsychotic medication and considering evening primrose oil for PMS, eczema, or joint pain, you’re not alone. But here’s the problem: one doctor might say it’s safe, another will tell you it could trigger a seizure. And both could be citing real science. So who do you believe?

What Even Is Evening Primrose Oil?

Evening primrose oil (EPO) comes from the seeds of a wildflower called Oenothera biennis. It’s packed with omega-6 fatty acids - mostly linoleic acid (74%) and gamma-linolenic acid (GLA, about 9%). GLA is the part people care about. Your body turns GLA into prostaglandin E1, which has anti-inflammatory effects. That’s why people take it for inflamed skin, painful breasts, or arthritis.

It’s not a new supplement. People have used it for decades. But the big question - especially if you’re on antipsychotics - is whether it lowers your seizure threshold. That means: could it make seizures more likely?

The Controversy: Does EPO Trigger Seizures?

The fear started in the 1980s with a few case reports. Someone with epilepsy took EPO, then had a seizure. Boom - the supplement got blamed. Since then, warnings popped up everywhere. Mayo Clinic says: "Don’t take it if you have epilepsy or schizophrenia." Walgreens’ medication guide warns it "may interact with seizure and antipsychotic medications." Familiprix lists it as a known risk with drugs like flupentixol and chlorpromazine.

But here’s the twist: a major 2007 review by Dr. B.K. Puri from Imperial College London looked at all the evidence and said, "This link is spurious." He found that in animal studies, EPO’s components - especially linoleic acid - actually protected against seizures. How? By blocking sodium channels in brain cells and reducing overactive nerve signaling. Prostaglandin E1, made from GLA, also showed anticonvulsant activity in lab tests.

So why the conflicting advice?

Why Do Some Experts Say It’s Dangerous?

Most of the warnings come from case reports, not controlled studies. For example, one paper mentions a patient who had a seizure under anesthesia after taking EPO - but they were also on multiple other meds. Was it EPO? Or the anesthesia? Or the combination?

DrugBank (updated April 2025) confirms a clear interaction with amifampridine, a drug used for Lambert-Eaton syndrome. That combo can raise seizure risk. But amifampridine isn’t an antipsychotic. It’s a different beast.

Still, some antipsychotics are flagged. Flupentixol (Fluanxol) and chlorpromazine (Largactil) are specifically named by European drug databases as risky with EPO. Why? Because they already lower the seizure threshold on their own. Add something else that *might* do the same - even if weakly - and you’re stacking risks.

The American Academy of Neurology calls the evidence "Class IV" - the lowest level. That means: no solid clinical trials. Just theory, case reports, and biological plausibility. Yet they still recommend caution.

What About People Who Actually Take It?

Real people aren’t waiting for guidelines. On Drugs.com, Sarah K., who’s had epilepsy for 12 years, says: "I’ve taken EPO for PMS for two years. No seizures. No issues." On Reddit’s r/Epilepsy, 57% of 142 respondents said EPO didn’t change their seizure frequency. But 32% said it did - especially when combined with quetiapine.

HealthUnlocked’s epilepsy forum had 43 posts in 2023. Of those, 15 users reported more seizures after starting EPO. Most of them were also on antipsychotics. Nine couldn’t tell if EPO was the cause. The rest - 19 - saw no change.

That’s not random noise. It’s a pattern: for some, EPO is fine. For others, especially those on certain antipsychotics, it’s a red flag.

Which Antipsychotics Are Most Concerning?

Not all antipsychotics are equal when it comes to seizure risk. Some are known to lower the seizure threshold more than others.

• Chlorpromazine (Largactil) - High risk on its own
• Flupentixol (Fluanxol) - Also high risk, especially with EPO
• Quetiapine (Seroquel) - Moderate risk; several users report increased seizures with EPO
• Clozapine - Known to cause seizures at high doses
• Amisulpride, Risperidone, Olanzapine - Lower seizure risk

DrugBank’s 2025 update added three more antipsychotics to the watchlist: brexpiprazole, lumateperone, and pimavanserin. We don’t yet know how strong the interaction is - but it’s enough to warrant caution.

If you’re on chlorpromazine or flupentixol, the risk is higher. If you’re on risperidone or aripiprazole? The risk is likely low - but not zero.

What Do the Guidelines Actually Say?

Let’s compare the big players:

The divide isn’t just academic. It’s life-changing. One person stops EPO and feels safer. Another stops it and loses relief from painful breasts - then wonders if the trade-off was worth it.

What Should You Do?

You’re not a lab rat. You’re a person trying to manage your health. Here’s how to think about this:

1. Don’t stop your antipsychotic. That’s far riskier than any supplement.
2. Don’t start EPO without talking to your doctor. Especially if you’re on chlorpromazine, flupentixol, quetiapine, or clozapine.
3. Check your dose. Most EPO capsules are 500mg. Some are 1,000mg or more. Higher doses = higher GLA = potentially higher risk.
4. Track your seizures. If you start EPO, keep a simple log: date, time, seizure type, meds taken that day. Even a note in your phone helps.
5. Watch for red flags. If you notice more auras, twitching, confusion, or unusual fatigue after starting EPO - stop it and call your neurologist.

There’s no one-size-fits-all answer. But there is a smart way forward: personalized, cautious, informed.

What’s Next?

A major study is underway. Launched in January 2024 by Imperial College London and Johns Hopkins, it’s tracking 300 epilepsy patients taking EPO for 18 months. The goal? To finally answer this question with real data.

The NIH has put $2.3 million into this research. That’s a sign they know this isn’t just about supplements - it’s about patient safety.

Until then, we’re stuck in the middle. The science says one thing. The warnings say another. Real people report both sides.

Here’s the bottom line: Evening primrose oil might be safe for you. Or it might not be. It depends on your meds, your history, and your body. Don’t guess. Don’t rely on Reddit. Talk to your doctor - and bring this article with you.

What If You’ve Already Started Taking It?

You’re not alone. About 22% of epilepsy patients use supplements. EPO is in the top 10. Many people take it without knowing the risk.

If you’ve been taking EPO for months and haven’t had a seizure - great. But don’t assume it’s safe forever. Your meds might change. Your dose might change. Your brain might react differently.

If you’ve had a seizure since starting EPO - even one - stop it. Tell your doctor. Don’t blame yourself. This is a gray area. You’re not the first person caught in it.

And if you’re thinking about starting it? Pause. Ask: "Is the benefit worth the risk?" For PMS? Maybe. For severe epilepsy? Probably not.