Midwives brew is a homemade drink intended to induce labor, typically made from castor oil, apricot juice, almond butter, and lemon verbena oil. It has circulated among pregnant people for decades as a natural alternative to medical induction, and its active ingredient, castor oil, does have real biological effects on the uterus. But those effects come with significant side effects, and the brew carries risks that deserve a clear explanation before anyone considers drinking it.
What’s in Midwives Brew
Recipes vary, but the core formula stays fairly consistent. Most versions combine about two tablespoons of castor oil with roughly 10 ounces of apricot juice, one tablespoon of almond butter, and a small amount of lemon verbena oil. The apricot juice and almond butter serve a practical purpose: they mask the taste and oily texture of castor oil, which most people find difficult to swallow on its own. Lemon verbena is sometimes included for flavor or because of a traditional belief that it supports uterine activity, though there is no strong clinical evidence for that specific claim.
The drink is typically blended together and consumed in one sitting. Some people drink it on an empty stomach in the morning, believing this speeds up absorption. Others eat a light meal beforehand to reduce nausea. There is no standardized recipe or dosage, which is itself a risk factor, since the amount of castor oil can vary widely between versions shared online.
How Castor Oil Triggers Contractions
Castor oil is not just a folk remedy. Its mechanism has been studied at the molecular level. When you swallow castor oil, enzymes in your intestines break it down and release a fatty acid called ricinoleic acid. This compound activates the same receptors in smooth muscle tissue that prostaglandins do. Prostaglandins are hormone-like substances your body naturally produces to ripen the cervix and stimulate uterine contractions during labor.
Ricinoleic acid specifically activates receptors found in both the intestines and the pregnant uterus. That dual action explains why castor oil causes both diarrhea and contractions at the same time. Research published in the Proceedings of the National Academy of Sciences confirmed this by showing that in mice engineered to lack these specific receptors, castor oil produced neither laxative effects nor uterine contractions. The compound is highly selective: closely related fatty acids that lack the same molecular structure had no effect at all.
This means the contractions castor oil produces are not a secondary response to intestinal distress. The same fatty acid directly stimulates the uterine muscle through a specific receptor pathway.
Does It Actually Work
The short answer is that castor oil does increase the likelihood of labor starting, and the effect is not subtle. A systematic review and meta-analysis found that 57% of people who took castor oil went into labor within 24 hours, compared to just 4% in control groups who received no treatment. Another analysis reported that regular uterine contractions began within 24 hours in 70% of the castor oil group versus 12% of the control group.
The overall odds of going into labor after castor oil were roughly 12 times higher than without it, a statistically significant result. One study found that over 50% of participants given castor oil entered active labor within a day, and this effect held regardless of the mother’s age or the baby’s weight.
Those numbers sound impressive, but context matters. Most of these studies involved women who were already at or past their due date, often with cervixes that had already begun to soften and dilate. Castor oil appears to work best when the body is already close to labor on its own. For someone whose cervix is still firm and closed, the brew is more likely to cause hours of gastrointestinal misery without producing meaningful progress.
Side Effects and Risks
The most common and virtually guaranteed side effect is diarrhea. Because ricinoleic acid stimulates the same receptors in the gut as in the uterus, nearly everyone who drinks castor oil experiences cramping, loose stools, and nausea within a few hours. For someone about to go through labor, starting out dehydrated and exhausted from hours of diarrhea is a real disadvantage. Dehydration can also affect how well the uterus contracts during actual labor, potentially making the process longer and harder.
Vomiting is another frequent side effect. Some people cannot keep the brew down at all, which means they get the gastrointestinal distress without any of the potential labor-inducing benefit.
A more serious concern is the possibility of intense, irregular contractions. Unlike medical induction, which can be carefully dosed and monitored, castor oil provides no way to control the strength or frequency of the contractions it produces. If contractions become too strong or too frequent, they can reduce blood flow to the baby, causing fetal distress. There is also a longstanding concern about meconium-stained amniotic fluid, where the baby passes its first stool before birth. If the baby inhales meconium during delivery, it can cause breathing problems. Some studies have noted higher rates of meconium staining in castor oil groups, though findings are mixed.
The brew is particularly risky for anyone with a high-risk pregnancy. If you have a history of cesarean delivery, placenta previa, preeclampsia, or if the baby is not in a head-down position, stimulating uncontrolled contractions could lead to dangerous complications including uterine rupture.
Timing and Prerequisites
People who use midwives brew generally do so at 39 or 40 weeks of pregnancy, often when they are past their due date and hoping to avoid a medical induction. The brew is not intended for use before 39 weeks, since the baby’s lungs, brain, and liver are still maturing during those final weeks.
Cervical readiness matters significantly. The cervix needs to have already started softening, thinning, and possibly dilating for castor oil to have a reasonable chance of tipping the body into labor. If none of that groundwork has happened, the brew is unlikely to produce contractions strong enough to result in active labor. A healthcare provider can assess cervical readiness during a routine late-pregnancy exam.
Even among people who meet these criteria, midwives brew is not a controlled medical intervention. There is no monitoring of the baby’s heart rate, no way to adjust the dose, and no quick reversal if something goes wrong. That lack of oversight is the fundamental difference between drinking castor oil at home and being induced in a hospital or birth center, where the same biological process can be managed with precision and real-time safety checks.
Why the Other Ingredients Matter Less Than You Think
Online discussions about midwives brew sometimes focus on the specific brand of apricot juice or the type of almond butter, as though fine-tuning these details will improve the outcome. In reality, castor oil is the only pharmacologically active ingredient. The apricot juice is a vehicle to make the oil drinkable. The almond butter helps emulsify the oil so it blends rather than floating on top. Lemon verbena oil adds flavor and has a traditional association with childbirth in some cultures, but no clinical trials support it as a labor-inducing agent on its own.
This means that the benefits and risks of midwives brew are essentially the benefits and risks of castor oil. The other ingredients don’t add therapeutic value, and swapping them out or adjusting their proportions won’t meaningfully change whether or not you go into labor. What determines the outcome is your gestational age, how ready your body already is, and how your system responds to ricinoleic acid.