What are the effects of evening primrose oil?

Eczema, Breast pain: The effectiveness of evening primrose oil stems from an ingredient called gamma-linolenic acid, or gla, an essential fatty acid thought to have anti-inflammatory and other healing properties. Evening primrose oil has highly concentrated amounts. It is one of the safest sources of gla. When ingested, gla is converted to prostaglandins, compounds that help regulate inflammation.