Evening primrose oil 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 are indeed a number of things you can do to prime your body for the task ahead. One possible option is evening primrose oil (EPO), which can be applied vaginally for the purpose of inducing labor.

Pregnant women like using evening primrose oil because it’s widely available and reasonably priced.

Still, 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.

What is evening primrose oil?

This oil comes from the evening primrose plant. It contains linolenic acid, gamma linolenic acid, and vitamin E. Over-the-counter EPO capsules can be purchased at most pharmacies or vitamin and herbal remedy stores. It’s 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 real effect on labor remains relatively unknown.

How it’s used

Evening primrose oil comes in capsules, which can be taken orally or inserted vaginally. While there is no standard dosage, it’s standard to take 500 to 2000 milligrams daily after the 38th week of pregnancy has begun. If you choose to use EPO, always start with very low doses.

Does it work?

According to American Family Physician, evening primrose oil may help the cervix soften and efface (thin out). Other studies suggest that it can help shorten labor duration. This is due to linolenic acid found in EPO, which may trigger a prostaglandin response in the body. Doctors and midwives may provide different guidelines depending on your unique medical history.

As far as its effectiveness, there aren’t enough formal studies on EPO to prove its impact on labor or cervical ripening. Studies that have been published generally don’t show a particularly strong association with the oil and kick-starting labor. For example, one study found that women taking the supplement were in labor three hours longer on average than those who didn’t take EPO.

Most of the positive experiences of evening primrose oil are anecdotal. The capsules are often taken in conjunction with other natural induction methods, including consumption of red raspberry leaf tea, nipple stimulation, and sexual intercourse. For this reason, it’s hard to isolate EPO’s individual effect on the process.

Pros and cons

While there is a lot of scientific research that still needs to be done to fully evaluate the safety and efficiency of EPO, there are some pros and cons we can consider based on the information we have now.

Pros of evening primrose oil

  • There are no known negative effects on breast-feeding.
  • 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 that must be considered.

Cons of evening primrose oil

  • 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.
Was this helpful?

Other safe ways to induce labor

There are other methods commonly used to help women naturally induce labor. These methods include:

  • exercising, which can include a walk or climbing a set of stairs
  • sexual intercourse
  • eating spicy foods
  • raspberry leaf tea, which is recommended by some midwives and thought to turn irregular uterine contractions into regular and productive ones

Always consult your doctor before attempting to induce labor. Do not try to induce labor before 40 weeks of pregnancy. Depending on medications you’re currently taking, underlying conditions, or complications with your pregnancy, it may be dangerous to attempt to induce labor on your own.


There isn’t much scientific evidence to prove that taking evening primrose oil to induce labor is either safe or unsafe. Many women use EPO without incident, but an early study found that the oral intake of EPO could trigger delivery problems or complications. Regardless, you shouldn’t take any supplement during pregnancy without consulting with your care provider.

You should 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.