Though there is good evidence suggesting that lower doses of evening primrose oil (EPO) are of value for reproductive imbalance (breast tenderness, PMS), higher doses are reportedly more effective for reproductive damage (inflammation, pain). Other sources of essential fatty acids such as flax, borage, or black currant seed oil are important for a rounded intake of healthy oils, but these do not act as quickly in women with endometriosis. For this reason, higher doses of the more expensive EPO may have to be used for the short term.