There is not enough evidence to support the use of evening primrose oil for any health condition.
Evening primrose oil is well tolerated by most people, when taken for short periods of time. Common side effects include abdominal pain or swelling, diarrhea, gas, nausea, upset stomach, and vomiting.
The safety of long-term use of evening primrose oil has not been established.
Evening primrose oil may interact with the following:
- anticoagulants (e.g., apixaban, warfarin)
- antiplatelets (e.g., acetylsalicylic acid (ASA), clopidogrel)
- certain types of antipsychotics called phenothiazines (e.g., chlorpromazine, prochlorperazine)
- lithium
- lopinavir
- ritonavir
Evening primrose oil should not be used by those who experience seizures. Stop taking evening primrose oil at least 2 weeks before surgery.
Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health products you may be taking.