Evening primrose is a plant that is native to North America but now grows wild all over the world. Its name comes from the fact that its yellow flowers tend to bloom in the evening.
Oil from the seeds of the evening primrose is used as a supplement for humans and pets due to its high concentration of the essential oil gamma-linolenic acid (GLA). Essential oils like GLA are needed by the body to remain healthy but since they cannot be made by the body, they have to be obtained from the diet.
Evening primrose oil is most commonly recommended as a natural anti-inflammatory for dogs with skin problems and joint issues and is also sometimes suggested for digestive upsets like colitis and irritable bowel syndrome (IBS).