Evening primrose oil (EPO) may help to soften the cervix, but it’s unclear if it effectively induces labor. Talk with your doctor or midwife before taking any supplements while pregnant.

If you’re beyond 40 weeks in your pregnancy, you may have heard of several natural ways to try and induce labor. There may be several things you can try to prime your body for the task ahead. One possible option is evening primrose oil (EPO), which can be applied vaginally to induce labor. Evening primrose oil is widely available and reasonably priced, making it a popular choice.

You might be wondering if it’s right for you. Here’s everything you need to know about this herbal supplement, its uses, and precautions.

Always talk with your OB-GYN or healthcare professional before taking any supplements during pregnancy.

Evening primrose oil (EPO) comes from the evening primrose plant. It contains linolenic acid, gamma-linolenic acid, and vitamin E. You can purchase over-the-counter EPO capsules at most pharmacies or vitamin and herbal remedy stores, which are considered .

EPO is sometimes used in alternative therapies for a variety of health issues, including neuropathy, premenstrual syndrome, menopause, and rheumatoid arthritis. But while it’s been taken for many years, EPO’s actual effect on labor remains relatively unknown.

EPO comes in capsules, which you can take orally or insert vaginally. While there is no standard dosage, it typically involves 500 to 2000 milligrams daily after the 37th to 40th week of pregnancy. If you choose to use EPO, always start with very low doses.

Follow any instructions from your OB-GYN or midwife.

Evening primrose oil may help the cervix soften and efface (thin out) and help shorten labor duration. This is due to linolenic acid found in EPO, which may trigger a prostaglandin response in the body. Your doctors or midwife may provide guidelines specific to your individual medical history and situation.

There aren’t enough formal studies on EPO to prove its effectiveness on labor or cervical ripening. Published studies generally don’t show a particularly strong association between EPO and kick-starting labor.

A 2023 meta-analysis of studies investigating EPO and labor induction found mixed results when reviewing seven studies — six randomized controlled trials and one quasi-experimental study with a control group. The combined studies, which included 920 women, were included in the meta-analysis. Though the results were mixed, they found the following significant results:

  • 652 women were in studies that measured labor progress using the Bishop score (a numerical evaluation of cervical dilation during labor). In this group, using EPO significantly increased the Bishop score.
  • Both vaginal and oral use of EPO increased the Bishop score significantly in the intervention group compared to the placebo group.

A 2019 randomized clinical trial had a different result and recommendation. This study found that EPO did not impact Bishop scores and recommended that EPO be banned from clinical practice and only used in clinical trials and research projects.

More scientific research needs to be done to fully evaluate the safety and efficacy of EPO. Here are some pros and cons if you are considering EPO to help induce labor.

Pros of evening primrose oil

  • There are no known negative effects on breastfeeding.
  • It’s commonly used by midwives around the world (not including the United States) as an alternative to harsher chemicals for preparing the cervix for labor.
  • It may reduce the need to medically induce labor.
  • While there may be advantages to using EPO, there are some cons to consider.

Cons of evening primrose oil

  • It’s an unregulated herbal supplement, so you can’t be sure of the dose’s strength or exactly what’s in it.
  • It can act as a blood thinner.
  • There is a chance that EPO could trigger complications or trouble with delivery.
  • It can come with side effects like headaches or gastrointestinal upset.
  • It may negatively interact with other medications you are taking.

According to the National Health Service (NHS), there’s no safe way to induce labor at home. Most OB-GYNs recommend that you don’t attempt to start your labor with home remedies. Some people report these methods have helped them go into labor, but there’s not enough research to say that any of them work.

These methods include:

  • nipple stimulation
  • safe exercise like taking a walk or climbing a set of stairs
  • sexual intercourse
  • eating spicy foods
  • raspberry leaf tea

Always consult your doctor before attempting anything to induce labor.

It’s not recommended that you try to induce labor before 40 weeks of pregnancy.

Depending on the medications you’re currently taking, underlying conditions, or complications with your pregnancy, it may be dangerous to attempt to induce labor on your own.

While some research suggests that EPO helps soften your cervix and may induce labor, other studies suggest it does not. Currently, there’s not enough scientific evidence to prove that taking evening primrose oil to induce labor is safe or completely effective.

Always speak with your OB-GYN or midwife before starting any new supplements at any stage of your pregnancy. The American College of Obstetricians and Gynecologists defines a full-term pregnancy as 39 weeks or longer. Since studies are lacking in this area, it’s best to avoid anything that might promote labor before your baby is fully mature.