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Evening Primrose Oil

Keywords: 

eczema, rheumatoid arthritis, breast pain, menopausal symptoms

Common Names: 

evening primrose oil, EPO

Latin Name: 

Oenothera biennis

Evening Primrose
© Steven Foster

On this page:

Introduction

This fact sheet provides basic information about evening primrose oil—common names, uses, potential side effects, and resources for more information. Evening primrose is a plant native to North America, but it grows in Europe and parts of the Southern hemisphere as well. It has yellow flowers that bloom in the evening. Evening primrose oil contains gamma-linolenic acid (GLA), an essential fatty acid. Essential fatty acids are required by the body for growth and development, and must be obtained from the diet.

What Evening Primrose Oil Is Used For

  • Evening primrose oil has been used since the 1930s for eczema (a condition in which the skin becomes inflamed, itchy, or scaly because of allergies or other irritation).
  • More recently it has been used for other conditions involving inflammation, such as rheumatoid arthritis.
  • Evening primrose oil is used for conditions affecting women’s health, such as breast pain associated with the menstrual cycle, menopausal symptoms, and premenstrual syndrome (PMS).
  • Other conditions for which evening primrose oil is used include cancer and diabetes.

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How Evening Primrose Oil Is Used

Evening primrose oil is extracted from the seeds of the evening primrose. The oil is usually put into capsules for use.

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What the Science Says

  • Evening primrose oil may have modest benefits for eczema, and it may be useful for rheumatoid arthritis and breast pain. However, study results are mixed, and most studies have been small and not well designed.
  • Evening primrose oil does not appear to affect menopausal symptoms.
  • Although some clinical trials have shown a benefit of evening primrose oil for PMS, the best-designed trials found no effect.
  • There is not enough evidence to support the use of evening primrose oil for other health conditions.

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Side Effects and Cautions

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Sources

  • Evening primrose oil. Natural Medicines Comprehensive Database Web site. Accessed at www.naturaldatabase.com on June 11, 2009.
  • Evening primrose oil (Oenothera biennis L.). Natural Standard Web site. Accessed at www.naturalstandard.com on June 11, 2009.
  • Shahidi F, Miraliakbari H. Evening primrose (Oenothera biennis). In: Coates P, Blackman M, Cragg G, et al., eds. Encyclopedia of Dietary Supplements. New York, NY: Marcel Dekker; 2005:197–210.

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For More Information

NCCAM Clearinghouse

The NCCAM Clearinghouse provides information on NCCAM and complementary health practices, including publications and searches of Federal databases of scientific and medical literature. The Clearinghouse does not provide medical advice, treatment recommendations, or referrals to practitioners.

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Office of Dietary Supplements (ODS)

ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public. Its resources include publications and the International Bibliographic Information on Dietary Supplements database.

NIH National Library of Medicine's MedlinePlus

This publication is not copyrighted and is in the public domain. Duplication is encouraged.

NCCAM has provided this material for your information. It is not intended to substitute for the medical expertise and advice of your primary health care provider. We encourage you to discuss any decisions about treatment or care with your health care provider. The mention of any product, service, or therapy is not an endorsement by NCCAM.

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NCCAM Publication No.: 
D341
Created: 
December 2006
Updated: 
July 2010

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