Interactions

Possible interactions include:

• Anticoagulants and anti-platelet medicines, herbs and supplements. These types of medicines, herbs and supplements keep blood from clotting. Taking evening primrose while also taking these medicines may raise the risk of bleeding.
• Cytochrome P450 3A4 substrates, also called CYP3A4 substrates. Use evening primrose with care if you take a medicine affected by these enzymes. One such medicine is the cholesterol-lowering lovastatin (Altoprev).
• Lopinavir-ritonavir (Kaletra). This medicine treats the infection caused by human immunodeficiency virus, also called HIV. Evening primrose oil might slow how quickly the body breaks down this medicine.
• Phenothiazines. These medicines treat serious mental health conditions. Taking evening primrose oil with phenothiazines may raise the risk of seizures in some people.