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Evening primrose oil

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Important evening primrose oil facts

Evening primrose is a flowering plant that grows in the wild in Europe and North America, whose yellow flowers only open up at sunset.

The whole plant (including the flowers) as well as the root have been used for centuries for medicinal purposes.

The most potent part of the plant is the oil in the seeds of the flowers, which contains gamma-linolenic acid (GLA). GLA is an essential fatty acid that the body converts into prostaglandins, which are hormone-like substances that have many metabolic functions in the body. The GLA in evening primrose oil, when converted into prostaglandins acts as an anti-inflammatory.

GLA is also found in mother's milk, some types of fish and spirulina. It is also found in borage seed oil and black currant seed oil, which actually have higher levels of GLA than evening primrose oil.

  • GLA is an omega-6 fatty acid
  • GLA is an important part of cell membranes
  • A deficiency of GLA can be a contributing factor of eczema
  • People on low-fat diets may be missing out on GLA and may be deficient in this very important nutrient
  • Although the body can manufacture its own GLA from fats/oil consumed, it is generally not enough and supplementation may be required for some people

Evening primrose oil and health

  • PMS - GLA in evening primrose oil may be helpful in relieving PMS symptoms, especially breast tenderness and swelling. GLA seems to work best if taken every day of the month together with Vitamin B6 (pyridoxine)
  • Diabetic neuropathy - one study showed significant reduction in pain, prevention of nerve damage, resulting in numbness and tingling and better blood flow in the extremities
  • Eczema - eczema usually occurs when the body cannot convert GLA from fat in the diet. Several studies have shown that people who took evening primrose oil for 3-4 months had alleviation of symptoms and took less drugs for their condition
  • Rheumatoid arthritis - in some studies, it has been shown that symptoms of joint pain and swelling improved in patients with this condition. GLA has an anti-inflammatory effect which is the reason most likely symptoms improved

People who wish to take an acidophilus supplement should talk to a medical professional BEFORE taking it.

Evening primrose oil recommended intake

Dosage of evening primrose oil depends on the condition that is being treated. A medical doctor and/or alternative health care provider can advise on individual cases - this information is provided as a guide only:

Lifestage Age Amount (per day)
INFANTS 0-12mths Not recommended
CHILDREN 1-8yrs Not recommended
CHILDREN 9-18yrs
Seek medical advice before taking it
ADULTS 19-50yrs
1000mg 3 times a day
(equiv 240mg GLA)
SENIORS 51+yrs 1000mg 3 times a day
(equiv 240mg GLA)
PREGNANT   Seek medical advice before taking it
LACTATING   Seek medical advice before taking it


Types of evening primrose oil supplements

Evening primrose oil is only found in one plant - evening primrose! Evening primrose oil supplementation is available in the following ways:

  • Soft gel capsules - liquid evening primrose oil is added to the capsules
  • Topical cream/gel - liquid evening primrose oil added to a cream or gel formula

Evening primrose oil supplementation checklist

  • Store in a cool, dry place away from light - preferably stored in the refrigerator
  • Look for a supplement with 10% total GLA
  • Take with meals to enhance absorption
  • Look for a supplement with added vitamin E - to ensure that the fatty acids in evening primrose oil are broken down and absorbed slowly

Evening primrose oil works best with

Overdosage, toxicity and cautions for evening primrose oil

No toxicity has been reported in healthy individuals but people with health problems should be careful with taking any supplements.

Pregnant women should not take borage oil supplements as there is a risk as they may induce early labour.


People with any of the medical conditions listed below should discuss supplementation with a medical professional BEFORE taking evening primrose oil:

  • People with schizophrenia - should avoid taking any supplements with GLA as it could worsen their condition
  • People taking blood thinning medications - such as Coumadin or Warfarin should seek medical advice before taking a chondroitin supplement, as there may be bleeding complications - talk to a medical professional
  • People on anti-convulsant medication for epilepsy- are not recommended to take essential fatty acid supplements as GLA can induce seizures- talk to a medical professional
  • People with diabetes - should be cautious using fish oil supplements as they can raise blood glucose levels and lower insulin production - talk to a medical professional

Large amounts of fish oil supplements (over 5gm/day) can cause blood to become dangerously thin and make bleeding happen more often.



  • Groff J L, Gropper SS, Hunt SM, Advanced Nutrition and Human Metabolism. West Publishing, USA, 1995
  • Horrobin DF. The role of essential fatty acids and prostaglandins in the premenstrual syndrome. J Reprod Med. 1983;28(7):465-468
  • Keen H, Payan J, AllawiJ, et al. Treatment of diabetic neuropathy with gamma-linolenic acid. The Gamma-Linolenic Acid Multicenter Trial Group. Diabetes Care. 1993;16(1):8-15
  • Shils ME, Olson JA, Shike M, Ross AC. Modern Nutrition in Health and Disease. 9th ed. Baltimore, Md: Williams & Wilkins; 1999:88-90, 1347-1348
  • Simopoulos AP. Essential fatty acids in health and chronic disease. Am J Clin Nutr. 1999;70(3 suppl):560S-569S

Last reviewed 21 April 2019