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Evening Primrose Oil (EPO)

Introduction: What is Evening Primrose Oil (EPO)?

Evening primrose (Oenothera biennis- in Latin) is a unique and attractive plant which is also known as evening star. This plant grows in the mild climate of North America and Europe as well as many other areas of the world with similar climates. Evening Primrose Oil (EPO) is produced from the seeds of this unique plant.

Active Ingredient

Evening primrose oil is used in medicines and cosmetics. The active ingredients in evening primrose oil are omega-6 essential fatty acid, gamma-linolenic acid (GLA) and linoleic acid (Essential Fatty Acid).The essential fatty acids are required by the body for growth and development.

How to use

Evening Primrose Oil is sold as herbal supplement and it is available in oral and topical form. Follow all directions on the product package. Doctors and Pharmacist can be consulted if there are uncertainties about the information given.


  • Evening primrose oil has been used for eczema (a condition in which the skin becomes inflamed, itchy or scaly because of allergies or other irritation). Besides, it also has been used for treating acne, psoriasis and other skin condition. Evening primrose oil has moisturizing and softening effects when it is used as a topical application on the skin.
  • Evening primrose oil also has been used for relief from the physical and psychological symptoms of pre-menstrual syndrome (PMS) such as breast pain due to hormonal changes during menstruation and menopausal symptoms such as hot flushes and excessive cramping.
  • Evening primrose oil has been used for conditions involving inflammation including rheumatoid arthritis. In this situation, gamma-linolenic acid in evening primrose oil inhibits the production of hormone-like chemicals in the blood called prostaglandins.


Evening primrose oil is herbal preparation. Dosing of herbal preparation is determined by variety factors, which includes:

  • Growing and harvesting condition
  • Plant parts
  • Extraction method that has been used

The recommended dose of evening primrose oil in most proprietary is 1-3 gram daily. However, doses of up to 8 gram daily have been used in eczema in the United States for adults. It is advisable to seek advice from doctor and pharmacist if the dose is higher than recommended dose.

Side Effects

Evening primrose oil is well tolerated by most people. The common side effects include:

  • Mild gastrointestinal effects
  • Diarrhoea
  • Bloating
  • Nausea
  • Flatulence


    1. Contraindications
      • Hypersensitivity to Evening primrose
      • In psychiatric disorder (schizophrenic) patients and those receiving epileptogenic drugs, Evening primrose oil may have the potential to manifest temporal lobe epilepsy (Newall,1966
      • There is no safety study on the use of Evening primrose oil during pregnancy and therefore is not recommended for use during pregnancy


  1. Medicines drug /food Interactions
  • Anticoagulant (A medicines used to prevent blood clots) Taking Evening primrose oil and anticoagulant together may increase the risk of bleeding. So, if it is taken together with anticoagulant, the sign and symptom of excessive bleeding must be monitored. Get professional advice from doctor or pharmacist.
  • Anticonvulsant [A medicines used to control (prevent) or stop seizures (convulsions)].Taking Evening primrose oil and anticonvulsant together may reduce the effectiveness of anticonvulsant, therefore should be avoided or used with caution.
  • Antiplatelet agents (A medicines used to prevent the platelets in the blood from clumping)Taking Evening primrose oil and antiplatelet together may increase the risk of bleeding. So, if it is taken together with antiplatelet the sign and symptom of excessive bleeding must be monitored.
  • PhenothiazinesSeizures have been reported when evening primrose oil was added to phenothiazines therapy in schizophrenic patients (Holman & Bell,1983; Vaddadi,1981). So avoid take Evening primrose oil with phenothiazines.


This information is a summary and does not have all information about the product. This is information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask doctor or pharmacist for complete information about this product and your specific health need.

Last reviewed : 23 April 2014
Writer : Munira bt. Muhammad
Reviewer : Che Pun bt. Bujang