Gamma-Linolenic Acid (GLA)

Origin: A type of omega-6 fatty acid found in evening primrose oil, black currant oil and borage oil.

Claims: Lessens joint pain, stiffness and swelling associated with rheumatoid arthritis (RA). Eases symptoms of Raynaud’s phenomenon and Sjögren’s syndromes.

What we know: Several studies show GLA is an effective treatment for reducing inflammation in RA with few side effects. GLA only works if taken orally; there is no evidence that these oils applied topically are effective. It also may regulate the immune system.

Studies: One of the most promising studies was a placebo-controlled trial of 56 patients with active RA who received 2.8 g GLA. Participants showed significant improvements related to joint pain, stiffness and grip strength at six months and progressive improvement in control of disease activity at one year. A smaller study found that a combination of evening primrose oil and fish oil (Efamol) significantly reduced the need for conventional pain relievers.

A 2005 study showed that people with Sjögren’s syndrome who took GLA and linoleic acid had significant improvement in eye discomfort and tear production.

Dosage: Capsules or oil; 2 g to 3 g daily in divided doses.


 May increase bleeding risk; avoid if you use blood thinners such as warfarin (Coumadin).