Evening primrose is a biennial herb that grows both wild and cultivated all over the United States. The plant prefers full sun and well-drained soils and thrives in meadows, fencerows and along roadways. Evening primrose gets its name from the large yellow blooms that open in the late afternoon. The herb has been used for centuries as both a food and for medicinal purposes. Currently, it is used in alternative medicine in both capsule and oil forms.
Purchase only certified evening primrose oil or capsules. The label should state that each recommended dose contains 8 percent gamma-linolenic acid, and is organic. The bottle should also carry an expiration date.
Take evening primrose in 2 to 8 gram dosages. Children should never be given more than half this amount.
Keep evening primrose in the refrigerator after opening. Because it is oil, it can become rancid at room temperature.
Discontinue use of evening primrose if you experience headaches, nausea or stomach pain. Loose stools are an indication that you are taking more than the recommended dose of the oil.
Avoid taking evening primrose if you are on medications for schizophrenia or are taking drugs with blood-thinning effects.