Omega-6 fatty acids are a vital part of our diet and perform a wide range of functions in the body. Although the basic building block, linoleic acid, is common in plant-based foods, there are often factors present which inhibit its onwards conversion and therefore many people supplement their diet with the metabolite g-linolenic acid (GLA). This fatty acid is uncommon, but is found in certain seed oils, such as evening primrose, borage and blackcurrant, of which evening primrose has been most widely used, and has been furthest developed. Mostly, these oils are packaged as soft-gelatine capsules, but there may be scope for wider use as food ingredients. The supply of these oils however can be unstable, with prices fluctuating substantially from year to year, and the various factors affecting this will be discussed.