Evening primrose oil is used as the source of gamma linolenic acid (GLA) in a range of nutritional and pharmaceutical products, where it helps to normalize lipid metabolism. The evening primrose (Oenothera spp.) is a native of North America and has only entered into cultivation as an oilseed crop within the last 25 years. Initially, semi-domesticated varieties (developed as garden ornamentals) were grown in low-wage economies of Eastern Europe. As the result of a long-term programme of genetic improvement and research into agronomic techniques, the crop was later transferred to the more mechanized agriculture of 'Western' countries were it could be grown more efficiently. The pendulum has now however swung back, and over 90% of world production takes place in China, where the combination of excellent yields and low labour costs have proved to be an unbeatable combination.