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Are there side effects or drug interactions for evening primrose?


There are indeed side effects and drug interactions for evening primrose. Possible side effects of evening primrose include indigestion, nausea or upset stomach, soft stools, and headache. Large doses of evening primrose can lead to loose stools and abdominal pain.

As with many other herbal products, evening primrose does have some potentially dangerous drug interactions:

  • Evening primrose oil, which contains gamma-linolenic acid (GLA), can have anticoagulant (blood-thinning) effects. Theoretically, taking evening primrose with other anticoagulant or antiplatelet drugs may increase the risk of bleeding.
  • Evening primrose also may interact with various seizure and antipsychotic medications, which can result in an increased risk of seizures.

As a result, if you currently are taking any seizure, antipsychotic, or blood-thinning medication, you should avoid evening primrose.

In addition, if you are taking any prescription medication, always consult your doctor or pharmacist before taking any herbal product.

Finally, the maximum safe dose of evening primrose for young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established.

Get more information about your prescription medications.

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Answers to questions regarding information about medications or health conditions are not for diagnostic or treatment purposes and are not conclusive as to the presence or absence of any health condition. Consult your physician for diagnosis and treatment of your medical condition. The information provided is not a substitute for medical advice. Advances in medicine may cause this information to become outdated, invalid or subject to debate. Professional opinions and interpretations of the scientific literature may vary. Walgreens' terms of use and general warranty disclaimer apply to all services provided. If you are in need of immediate medical attention, contact your physician, poison control center or emergency medical professional. If you need to speak with a pharmacist for non-emergency matters, contact your local Walgreens pharmacist or call a pharmacist toll-free at 1 (877) 250-5823.

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