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Gamma Linolenic Acid (GLA)

Common names: Gamma linolenic acid also is known as GLA and gamolenic acid.

Efficacy rating:

ÒÒÒ...Positive clinical trials

Safety rating:

...No safety concerns despite wide use.

What is Gamma Linolenic Acid (GLA)?

GLA is found in the seeds and oils of a range of plants including Onagraceae (evening primrose), Saxifragaceae (borage), and Rubaceae (blackcurrant). The richest source of GLA is borage (Borago officinalis).

What is Gamma Linolenic Acid (GLA) used for?


Fatty acids are the basic building blocks for all lipids. They consist of chains of carbon and hydrogen with an end acid group. Fatty acids vary in length and degree of saturation and generally are up to 26 carbons long. The polyunsaturated fatty acids contain more than 1 double bond. The double bonds are at carbon 3 (n-3) or 6 (n-6). GLA falls into the latter family, known as omega-6 fatty acids.

The actual location of the double bond significantly affects metabolism of the fatty acid, such that the structure and function of omega-3 derived eicosanoids differ from those derived from the omega-6 fatty acids (eg, arachidonic acid). For example, omega-3 derived eicosanoids tend to decrease blood clotting and inflammatory responses. This contrasts significantly with the arachidonic acid (omega-6) derived eicosanoids, which increase clotting and inflammatory responses.

Unsaturated fatty acids are essential components of cell membranes and can influence receptors, enzymes, ion channels, and signal transduction pathways. They can influence numerous inflammatory and immunological processes.

Traditional/Ethnobotanical uses

The evening primrose plant is native to North America and was introduced into Europe in the 17th century. Native Americans consumed the leaves, roots, and seedpods as food and prepared extracts of the oil for use as a painkiller and asthma treatment. Some of these early therapeutic effects are thought to be because of GLA, which is found in high quantities in the oil.

In the 1930s and 1940s, several investigators found dietary supplementation with essential fatty acids such as GLA to be of therapeutic value in atopic dermatitis (AD). The advent of topical glucocorticoids brought an end to this form of treatment. However, by the early 1980s, there was a return to using these agents because of the unwanted side effects of glucocorticoids, and they have regained scientific interest. Over the last 2 decades, numerous other indications have been proposed for GLA.

Rheumatoid arthritis

Clinical studies using GLA (evening primrose oil, borage seed oil, blackcurrant seed oil) suggest a potential relief of pain, morning stiffness, and joint tenderness in rheumatoid arthritis sufferers. Benefits appeared to be increased when dosages were greater than 1.4 g/day of GLA, and administered for at least 6 months.

Cardiovascular protection

The apparent low death rate from coronary heart disease among Eskimos has focused interest on the potential benefits of the n-3 polyunsaturated fatty acids. A small clinical study showed benefits in lowering total cholesterol and LDL, and raising HDL cholesterol. These effects suggest that GLA may contribute to cardiovascular protection. However, this is still an area of controversy.

Diabetes mellitus

GLA has been studied as for its possible benefits for diabetic neuropathy. Diabetic patients have abnormalities of essential fatty acid metabolism, and therefore require higher amounts of essential fatty acids. Studies have shown that the development of cataracts, retinopathy, and cardiovascular damage can all be slowed by the administration of large daily doses of essential fatty acid. Clinical studies have demonstrated consistent and progressive improvement of neuropathies when treated with GLA.

Atopic diseases/Asthma/Psoriasis

GLA has been shown in clinical studies to reduce itching, redness, and toughness of atopic skin. GLA also reduces the inflammation and overall severity of atopic dermatitis, while atopic disease in children often presents as bronchial asthma later in life. However, there have been no animal or clinical studies regarding the use of GLA for atopic bronchial asthma. Although psoriasis does not have an atopic component, the use of GLA has been investigated clinically with inconsistent results.

Other uses

GLA supplementation has been shown to increase lymphocytes, a key component in immune response. It also has been proposed that GLA may play important roles in cancer treatment. Small clinical studies have shown some improvement in immunologic status with estrogen-sensitive breast cancer and bladder cancer. Clinical studies have shown that GLA is effective in relieving PMS symptoms, including breast pain.

What is the dosage of Gamma Linolenic Acid (GLA)?

GLA has been studied clinically for a wide variety of conditions, including asthma, dermatitis, and arthritis. Oral doses in trials have ranged from as little as 0.5 to 3 g per day.

Is Gamma Linolenic Acid (GLA) safe?


Contraindications have not yet been identified.


Not to be used by pregnant women and nursing mothers unless recommended by a physician.


None well documented.

Side Effects

No serious adverse effects have been noted.


Research reveals little or no information regarding toxicology with the use of this product.


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Further information

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