Evening primrose oil

It is pressed from the seeds of the evening primrose, a flowering plant in the genus Oenothera. The oil is sold both as a bottled oil and in capsules.

It is usually sold as a supplement rather than a cooking oil. Avoid frying with it: heat can damage its delicate polyunsaturated fats.

Bottled oil has a mild, slightly nutty taste. If you use it in food, add it to a cold dressing or drizzle it over food after cooking rather than heating it.

Keep bottled oil tightly closed, away from light and heat; refrigerate it after opening if the packaging advises this. Discard it if it develops a sharp, stale or paint-like smell.

Swallow capsules with water, usually alongside a meal if that is more comfortable for you. Capsule strengths vary, so follow the directions for the particular product rather than assuming all capsules contain the same amount.

It is rich in polyunsaturated fat, including gamma-linolenic acid (GLA), an omega-6 fatty acid. Its composition is one reason it is generally used without heating.