What Is Evening Primrose Oil (EPO)?

Evening primrose oil has been used to help women with fertility, and with menstrual issues, for hundreds of years. This oil has been cold-pressed from the seeds of the Oenothera biennis (evening primrose) plant, which is, strangely, not a primrose at all, but gets its name from the fact that the flower looks similar to English Primrose.

Its healing properties were first discovered in Medieval Europe when it was called the “King’s cure-all” because it helped fight many ailments and illnesses. Currently, it is still used to help with a variety of physical issues - everything from eczema to high blood pressure to fertility issues and pre-menstrual syndrome. It is even used as a home remedy for women at the end of their pregnancy to help induce labor.

Evening primrose oil is high in omega 3 and omega six fatty acids, especially linoleic acid (LA) and gamma linoleic acid (GLA). These two acids are necessary for the production and synthesis of prostaglandin E in a woman’s body.  

What Does Evening Primrose Oil Do? 

Promotes Hormone Balance in Women

Prostaglandins act in a woman’s body to regulate hormones in the pituitary gland and elsewhere. Since there are so many female sex hormones released at different times in a woman’s cycle, prostaglandins can have an especially important role in female fertility.

Evening primrose oil also seems to have a direct effect on a woman’s uterus. Its effect appears to be to make the uterus contract slightly and to strengthen the cells in the uterine wall. Because of this, women are warned against using evening primrose oil during pregnancy, except at the end when the woman is trying to induce labor.

These small contractions are thought to potentially lead to miscarriage in early pregnancy by stimulating the uterus to contract. Women trying to conceive are encouraged to take evening primrose oil to maintain hormonal balance and reproductive health. Because of the cervical contractions, women should only use this supplement through menstruation until ovulation to avoid potential adverse side effects if the fertilized egg ends up implanting in the uterus.

Supports Production of Fertile Cervical Mucus

Evening primrose oil can also positively influence a woman’s cervical mucus, making it thinner and more plentiful. Ideal cervical mucus will be the consistency of raw egg white: thin and sticky. This cervical mucus helps to keep the sperm safe and move them into the cervix to fertilize the egg.

If a woman is not trying to conceive, she can still experience the hormonal benefits of evening primrose oil to help with negative symptoms of pre-menstrual syndrome and menstruation. In that case, she can take evening primrose oil throughout her entire cycle to help maintain hormone balance and uterine health.

What How Much EPO Should You Take and When?

As with many other hormonal supplements, it may take one or two months to feel the desired effect. It is recommended that women take 1500 – 3000 mg daily.  It is recommended that you take the EPO from the first day of your period until you ovulate (for about 14 days) if you are trying to get pregnant.    After you ovulate,  you can take Flaxseed oil or other sources of omega fatty acids.

DON'T Take EPO If You Take These Classes of Medications

If you take medications for blood pressure, blood thinners, or SSRIs, it is highly advised that you discuss your desire to take Evening Primrose Oil with your doctor first.

While these are the main classes that EPO can interact with, if you are taking ANY medications, it is always best to discuss adding any supplement to your daily practice with your doctor before you start.