Implications for practice  

Oral borage oil and evening primrose oil lack effect on eczema; improvement was similar to respective placebos used in trials. Oral BO and EPO are not effective treatments for eczema.
In these studies, along with the placebos, EPO and BO have the same, fairly common, mild, transient adverse effects, which are mainly gastrointestinal.
The short-term studies included here do not examine possible adverse effects of long-term use of EPO or BO. A case report warned that if EPO is taken for a prolonged period of time (more than one year), there is a potential risk of inflammation, thrombosis, and immunosuppression; another study found that EPO may increase bleeding for people on Coumadin® (warfarin) medication.

Implications for research 

Noting that the confidence intervals between active and placebo treatment are narrow, to exclude the possibility of any clinically useful difference, we concluded that further studies on EPO or BO for eczema would be hard to justify.
This review does not provide information about long-term use of these products.
Evening primrose oil in the treatment of atopic eczema: effect on clinical status, plasma phospholipid fatty acids and circulating blood prostaglandins.
In a double-blind trial patients with atopic eczema received either oral evening primrose oil (EPO) (n = 14) or placebo (n = 11) for 12 weeks. In the EPO group a statistically significant improvement was observed in the overall severity and grade of inflammation and in the percentage of the body surface involved by eczema as well as in dryness and itch. Patients in the placebo group showed a significant reduction in inflammation. The patients receiving EPO showed a significantly greater reduction in inflammation than those receiving placebo. Evening primrose oil caused a significant rise in the amount of dihomogammalinolenic acid in the plasma phospholipid fatty acids. Plasma levels of TXB2, 6-keto-PGF1 alpha and PGE1, and the amount of TXB2 released into serum during clotting were not altered by evening primrose oil.