(British Medical Journal) -- Borage oil (sold as starflower oil in chemists and health food shops) does not improve symptoms of eczema, despite some studies suggesting a dose related benefit, finds a study in this week's BMJ.

Purified borage oil contains a minimum of 23% gamma linolenic acid (GLA), an essential fatty acid that is needed for normal skin function. Evening primrose oil also contains GLA, but in lower concentrations.

Researchers identified 151 patients with atopic eczema. Every day for 12 weeks they received either high dose borage oil (containing 920 mg of GLA) or placebo in matching capsules. Symptoms were scored using recognised scales.

The symptoms and signs improved to a similar degree in both groups, with a marginally greater improvement in the placebo group. The authors suggest that GLA is unlikely to offer any useful benefit in treatment of atopic eczema.

This study, along with the recent decision of the UK Medicines Control Agency to withdraw the product licence for evening primrose oil, suggests that GLA supplementation for atopic dermatitis has had its day, writes a skin specialist in an accompanying editorial.