EVENING PRIMROSE OIL: July 2011

Evening Primrose Oil for Atopic Dermatitis

Interest was fuelled because evening primrose oil extract (containing 8-10% of gamma linolenic acid (GLA)) appeared to cause few side effects and because there was a very plausible mechanism to explain why supplementation with this essential fatty acid might work in atopic dermatitis. Since then many studies have evaluated the efficacy of oral gamma linolenic acid supplementation for atopic dermatitis, with conflicting results. Fifteen studies (10 dealing with evening primrose oil, and five with borage oil, which contains even higher concentrations of GLA) were summarised in a systematic review of atopic dermatitis treatments that I and others

conducted for the NHS Health Technology Assessment programmes. Medicines Control Agency’s decision to withdraw the product licence, suggests that GLA supplementation for atopic dermatitis has had its day.

Yet many questions surrounding the story of evening primrose oil for eczema remain unanswered:

Unanswered questions

In 1989 Horrobin et al published a meta-analysis in the British Journal of Dermatology of the two earliest studies plus another seven small (14-47 participants) company sponsored studies of evening primrose oil (Epogam, Scotia Pharmaceuticals) for atopic dermatitis. They found that atopic dermatitis improvement scores for evening primrose oil were significantly better

seven company trials included in that study have never since appeared in the public domain, the other concern about that meta-analysis was its exclusion of the one other independent and relatively large study (123 participants) by Bamford .

The company authors of the meta-analysis suggested that active versus placebo treatments became mixed up in the Bamford study, based on an analysis done by the company of fatty acid levels in blood samples taken from study participants. After this meta-analysis was published,

others thought it odd that Bamford et al never published a response to the company’s serious

criticisms of their study.10 In fact Bamford immediately wrote a lengthy and clear explanation of the steps that were in place to avoid such purported contamination, but he was refused an opportunity to defend his study with a published response because the journal decided that Bamford’s response did not add anything to the understanding on the use of evening primrose oil as a supplemental treatment for atopic eczema (J Bamford, written communication 12 Nov 2003).

A year later, two British dermatologists wrote a detailed review article on evening primrose oil and atopic dermatitis. 27 November 2003).

Too little data in the public domain

The Health Technology Assessment systematic review published in 2000 provided an opportunity for the company to hand over its unpublished studies for inclusion in that report.5 Although Searle wrote back to tell us that they would be “compiling the data,” no data have

been forthcoming to date.We can only hope that it will be compiled in time for the current Cochrane review on GLA supplementation for atopic dermatitis. Finally, in the autumn of 2002 the Medicines Control Agency withdrew the marketing authorisations for evening primrose oil following a “review of all the relevant information, including new studies,” although which information and new studies is unclear from the very limited information available on the agency’s website.

In fairness to the innovators of evening primrose oil for atopic dermatitis, they evaluated their product more than many other products used in dermatology. Nobody would have been happier than myself if evening primrose oil had produced a clinically worthwhile benefit for eczema sufferers. But the history of its development has been marred by lack of data in the public domain. As we bid goodnight to the evening primrose oil story, perhaps we can awaken to a world where all clinical trial data, derived from people who are good enough to volunteer for such studies, reach the light of day, where they can be openly debated in the public domain

EVENING PRIMROSE OIL - ORAL

USES: Evening primrose oil has been used for decreasing the risk of heart disease by lowering cholesterol and by decreasing the risk of blood clots (decreased platelet aggregation). It has also been used for controlling symptoms of premenstrual syndrome (PMS), to reduce breast pain, to decrease symptoms of cystic breast disease as well as for skin conditions (eczema). Some herbal/diet supplement products have been found to contain possibly harmful impurities/additives. Consult your doctor or pharmacist for more details.

HOW TO USE EVENING PRIMROSE OIL: Take this product by mouth as directed. Follow all directions on the product package. If you are uncertain about any of the information, consult your doctor or pharmacist. If your condition persists or worsens, or if you think you may have a serious medical problem, seek immediate medical attention.

SIDE EFFECTS OF EVENING PRIMROSE OIL: Indigestion, nausea, soft stools, or headache may occur. If any of these effects persist or worsen, contact your doctor promptly. If you notice other effects not listed above, contact your doctor or pharmacist.

Liquid preparations of this product may contain sugar and/or alcohol. Caution is advised if you have diabetes, alcohol dependence or liver disease. Ask your doctor or pharmacist about the safe use of this product. Consult your doctor before using this product. Consult your doctor before breast-feeding.

Evening Primrose Oil- Counter impotence and female infertility

Evening Primrose Oil for Atopic Dermatitis

EVENING PRIMROSE OIL - ORAL