Evening Primrose Oil in pregnancy and breastfeeding

What NCCIH says about safety

Evening primrose oil is probably safe for most adults when taken orally. Less is known about its safety for children. Evening primrose oil is generally well tolerated. The most common side effects are gastrointestinal symptoms such as abdominal pain, nausea, or diarrhea. If you take any type of medicine, talk with your health care provider before using evening primrose oil or other herbal products; some herbs and medicines interact in harmful ways. Evening primrose oil may be safe for use during pregnancy and while breastfeeding, but the evidence is not conclusive. The reported side effects of using evening primrose oil to try to get labor started have mostly been mild, but the long-term safety of using evening primrose oil in this way has not been established. Taking evening primrose oil during breastfeeding increases the concentration of gamma-linolenic acid (GLA) in breast milk but has not been linked to harmful effects in the infant.

Quoted in full from NCCIH so nothing is lost in summarising. Where they say “little is known”, that means the studies do not exist — not that the herb is known to be safe, and not that it is known to be harmful.

How much is actually known

A substantial number of studies in people have evaluated evening primrose oil for atopic dermatitis or breast pain or for starting labor. Less evidence is available on other potential uses.

What the research has found

There’s not enough evidence to support the use of evening primrose oil for any health condition. Evening primrose oil, taken orally, has not been shown to be helpful for relieving symptoms of atopic dermatitis. Evening primrose oil is probably not more effective than a placebo (an inactive substance) for breast pain. It has been suggested that evening primrose oil might help to get labor started at the end of pregnancy by increasing the production of substances called prostaglandins. However, studies that have tested evening primrose oil, administered either orally or vaginally, for this purpose have had inconsistent results. There’s insufficient evidence to show whether evening primrose oil is helpful for other conditions, such as rheumatoid arthritis, PMS, and menopause symptoms.

Before you take this

Dose and form change the answer completely. A culinary amount of a spice, a cup of tea, and a concentrated supplement extract are three different things, and most research is done on the last of them.

Supplements are also not regulated like medicines, so strength and purity vary between products. Bring the actual bottle to your midwife, doctor or pharmacist — that conversation is worth more than any page, including this one.