Supplement Forms/Alternate Names
- Omega-6 Oil(s)
- Omega-6 Fatty Acids
- Sources of GLA Include: Black Currant Seed Oil, Borage Oil, Evening Primrose Oil
Principal Proposed Uses
Other Proposed Uses
- GLA Alone: Attention Deficit and Hyperactivity Disorder (ADHD)
- Cyclic Mastalgia
- Dry Eyes (in Contact Lens Wearers)
- Kidney Stones
- Premenstrual Syndrome (PMS)
- Raynaud's Phenomenon
- Rheumatoid Arthritis
- Ulcerative Colitis
- Weight Loss
- In Combination with Fish Oil : Attention Deficit and Hyperactivity Disorder (ADHD)
- Huntington’s Disease
Probably Not Effective Uses
GLA (gamma-linolenic acid) is one of the two main types of essential fatty acids . These are "good" fats that are as necessary for your health as vitamins. Specifically, GLA is an omega-6 fatty acid. (For more information on the other major category of essential fatty acids, omega-3, see the article on fish oil .)
The body uses essential fatty acids to make various prostaglandins and leukotrienes. These substances influence inflammation and pain; some of them increase symptoms, while others decrease them. Taking GLA may swing the balance over to the more favorable prostaglandins and leukotrienes, making it helpful for diseases that involve inflammation.
There is some evidence that GLA may be helpful for diabetic neuropathy . The supplement is widely used in the UK and other parts of Europe to treat eczema and cyclic mastalgia (a condition marked by breast pain associated with the menstrual cycle). Current evidence, however, suggests that it may not help. There are many other proposed uses of GLA based on fairly weak evidence.
Very little GLA is found in the diet. Borage oil is the richest supplemental source (17% to 25% GLA), followed by black currant oil (15% to 20%) and evening primrose oil (7% to 10%). Borage and evening primrose are the most common sources used in studies.
The typical dosage of GLA when it is used in hopes of alleviating cyclic mastalgia or eczema is about 200 to 400 mg daily (about 2 to 4 g of evening primrose oil or 1 to 2 g borage oil). Diabetic neuropathy is typically treated with about 400 to 600 mg daily (about 4 to 6 g of evening primrose or 2 to 3 g of borage oil), and in rheumatoid arthritis doses as high as 2,000 to 3,000 mg have been tried. (Doses this high can only be obtained from purified GLA, as one would need impractically high doses of evening primrose oil or borage oil to get enough).
GLA should be taken with food. Full benefits (if there are any) may take more than 6 months to develop.
Thus far, we have mentioned only a fraction of the conditions for which GLA has been proposed as a treatment. Others include: asthma , allergies , bursitis , endometriosis , heart disease , irritable bowel syndrome , prostate cancer , benign prostatic hyperplasia (BPH) , and Sjogren's disease . However, none of these potential uses has as yet been scientifically evaluated to any significant extent.
What Is the Scientific Evidence for Gamma-Linolenic Acid?
Despite the fact that GLA (usually as evening primrose oil) is widely used in Europe to treat eczema , it appears most likely that the treatment is not truly effective. The anecdotes of cure that abound are, most likely, simply testimonials to the placebo effect (as well as a strong marketing campaign by one evening primrose oil supplier).
Cyclic mastalgia , also known as fibrocystic breast disease, cyclic mastitis, and mastodynia, is a condition in which a woman's breasts become painful during the week or two before her menstrual period. The discomfort is accompanied by swelling, inflammation, and sometimes actual cysts that form in the breasts. It is often associated with other symptoms of premenstrual syndrome (PMS) .
Other Premenstrual Symptoms
The explanation for the discrepancy may lie in the differences between the women studied. The first study involved women living in nursing homes, while the second studied healthier women living on their own. The latter group of women may have been better nourished and already received enough essential fatty acids in their diet.
Considering the contradictory nature of this evidence, more research is necessary to determine whether evening primrose oil is really useful for weight loss.
Most of the safety information we have regarding GLA comes from experience with evening primrose oil.
The maximum safe dosage of GLA for young children, pregnant or nursing women, or those with severe liver or kidney disease has not been established.
- Reviewer: EBSCO CAM Review Board
- Review Date: 09/2014 -
- Update Date: 09/18/2014 -