After 40 long weeks of pregnancy, you may be thinking that enough is enough.

By now, friends and family have probably started giving you tips and tricks for inducing labor. But if your baby’s showing no signs of vacating your uterus anytime soon, you might want to try castor oil. It’s an old standby that comes from the castor bean of the castor plant.

It’s thought that the practice of using castor oil to induce labor dates back to the Egyptians. Even today, it remains an old wives’ tale for jump-starting labor.

Here’s what you need to know about the do’s and don’ts of using castor oil to induce labor.

Castor oil is derived from the seeds of a plant called Ricinus communis. It’s native to India. The chemical composition of castor oil is unusual because it’s comprised mainly of ricinoleic acid, a fatty acid.

It’s this high concentration that likely gives castor oil the reputation for having various healing properties. For thousands of years, the oil has been used medicinally all over the world for various ailments, such as:

  • treating gastrointestinal problems like constipation
  • treating a variety of infections and skin conditions
  • treating pain and inflammation
  • stimulating the immune system

While there’s little scientific evidence to support these claims, anecdotal evidence abounds.

Today, castor oil can be found in many nonmedicinal applications:

  • Castor oil is used as a mold inhibitor, food additive, and flavoring agent.
  • It’s often added to skin care products and cosmetics like shampoos, soaps, and lipsticks.
  • Castor oil is used in manufacturing goods like plastics, fibers, paints, and more.

The thick oil is also famous for its foul taste. Its side effects can be unpleasant and even dangerous. It can cause everything from nausea and diarrhea to severe dehydration.

Castor oil may be best known as a laxative. It’s thought that there’s a relationship to this and its reputation for jump-starting labor.

Ingesting small amounts of castor oil can cause spasms in the intestines, which can stimulate the bowels and vagal nerve. This spasm-and-stimulation duo may then irritate the uterus, which can begin contracting.

It’s also thought that castor oil may reduce fluid absorption and electrolytes in the small intestine. This can cause diarrhea and possibly contractions. Castor oil might also promote the release of prostaglandin receptors, leading to the cervix dilating.

The results of castor oil inducing labor are mixed. A small study published in Alternative Therapies of Health and Medicine revealed that over half of those dosed with castor oil went into active labor within 24 hours. This is compared to only 4 percent beginning labor in the same timeframe without any treatment.

But another larger study, published nearly 10 years later in the Australian and New Zealand Journal of Obstetrics and Gynaecology, again looked at using castor oil.

It determined that while there were no harmful effects associated with castor oil to either mother or baby, it wasn’t particularly helpful at inducing labor, either.

When it’s effective at beginning labor, castor oil may cause irregular and painful contractions, which can be stressful to mom and baby alike. This can lead to exhaustion.

It may also cause your baby to pass meconium, or their first stool, before delivery. This can be problematic after birth.

According to the American Congress of Obstetricians and Gynecologists, a pregnancy is considered full-term between 39 weeks and 40 weeks, 6 days.

Between 41 weeks and 41 weeks, 6 days, it’s considered late-term. After 42 weeks, it’s post-term.

In most cases, inducing labor is a medical decision made for the safety of you and your baby. You’ll likely be induced in the following situations:

  • You’re nearly two weeks past your due date and labor hasn’t begun.
  • You aren’t having contractions, but your water has broken.
  • You have an infection in your uterus.
  • Your baby isn’t growing at the expected rate.
  • There isn’t enough amniotic fluid around your baby.
  • You’re experiencing placental abruption.
  • You have high blood pressure, diabetes, or another condition that could put you or your baby at risk.

If none of these situations apply to you, your pregnancy is full-term, and you’re ready to get the show on the road, you may consider trying other methods to jump-start labor.

These include:

  • eating spicy foods
  • having sex
  • nipple stimulation
  • acupressure

There’s no scientific evidence that show that these methods work. It may be frustrating, but usually there’s nothing to do but wait.

Before you decide to try to induce labor with castor oil, you should consult your doctor. Every pregnancy is different. Castor oil might be dangerous if you have other complications.

If you do get the go-ahead, be sure to follow your doctor’s dosing recommendations. Typically, women are advised to take castor oil in the morning. That way, it’s easier to monitor your symptoms and for you to stay hydrated.

Whatever happens, try not to worry too much. Your baby will be here eventually!