Most methods that cause contractions work by triggering the release of prostaglandins or oxytocin, two hormones your body already uses to start labor naturally. Whether you’re exploring ways to encourage labor on your own or trying to understand what happens during a medical induction, the options range from simple physical techniques you can try at home to clinical procedures performed by your care provider. Timing matters: for healthy pregnancies, induction before 39 weeks is associated with worse outcomes for the baby.
How Contractions Actually Start
Labor contractions depend on two key hormones. Prostaglandins soften and thin the cervix (a process called ripening) and also stimulate the uterus to contract. Oxytocin drives strong, rhythmic contractions that push the baby down. Nearly every method of starting labor, whether natural or medical, works by boosting one or both of these hormones.
Before any induction method is likely to succeed, your cervix needs to be ready. Providers assess this using a scoring system based on five factors: how dilated the cervix is, how thin it has become, how soft it feels, its position, and how far the baby’s head has descended into the pelvis. A higher score means your body is already moving toward labor, and induction is more likely to work quickly. A low score often means cervical ripening needs to happen first.
Natural Methods You Can Try at Home
Breast Stimulation
Stimulating the nipples causes the uterus to contract, likely by increasing oxytocin levels. In clinical trials, women were typically instructed to stimulate their breasts for one hour, three times per day, alternating between breasts every 10 to 15 minutes. Some study protocols used shorter sessions of one hour total per day over three consecutive days. This is one of the more well-studied natural approaches, and it can produce measurable contractions strong enough to be used in fetal stress testing.
Sexual Intercourse
Semen contains one of the highest natural concentrations of prostaglandins found in any biological source, which is why intercourse is often suggested as a way to ripen the cervix. Orgasm may also trigger oxytocin release, and the physical stimulation of the lower uterus could play a role. That said, clinical trials have not produced enough data to confirm that intercourse reliably induces labor. It’s low risk for most pregnancies but more of a “can’t hurt” option than a proven method.
Castor Oil
Castor oil has a long history as a folk remedy for starting labor, and some research does support its effectiveness. However, it fell out of favor after the 1950s because of its side effects. Nausea is the most common problem, affecting roughly half of women who take it in some studies compared to none in control groups. Diarrhea occurs in nearly every woman who uses it. A few studies reported slightly higher rates of postpartum hemorrhage in castor oil groups, though the differences were not statistically significant. No maternal deaths or increases in stillbirth have been linked to its use, and most side effects are described as mild and manageable.
Red Raspberry Leaf Tea
Red raspberry leaf tea is widely marketed as a labor-preparation tool, but the evidence is mixed. Lab studies show that raspberry leaf contains compounds with both stimulating and relaxing effects on smooth muscle, and the effects seem to depend on whether the uterine tissue is pregnant or not. One study found a stimulatory effect on pregnant human uterine tissue specifically. In human trials, though, no clear benefit or harm has been demonstrated. One study found a modest reduction in the length of the pushing stage, but the result wasn’t statistically significant. It’s better understood as a uterine toner than a contraction trigger.
Acupressure
Pressing on specific points on the body may encourage oxytocin release. The most commonly referenced point is located about four finger-widths above the inner ankle bone. Another is near the ankle on the outer side of the foot, between the Achilles tendon and the ankle bone. Research suggests these points may affect uterine contractions by stimulating oxytocin secretion from the pituitary gland. The evidence is limited but the approach carries very little risk.
Membrane Sweeping
A membrane sweep is something your provider can do during a regular cervical exam. They use a finger to separate the amniotic membrane from the lower part of the uterus, which releases local prostaglandins and can kickstart labor. It sits in a gray area between “natural” and “medical” since it requires a provider but doesn’t involve medication.
One study found that 98% of women who underwent serial membrane sweeping (every 48 hours starting at 40 weeks) went into spontaneous labor, compared to just 46% of those who did not have the procedure. Even a single sweep can be effective, and it’s commonly offered to women approaching or past their due date to reduce the need for formal induction.
Medical Induction Methods
Prostaglandin Medications
Synthetic prostaglandins are the most commonly used agents for starting labor in a hospital setting. They come in gels, tablets, or slow-release inserts placed near the cervix. These medications both ripen the cervix and stimulate uterine contractions. They increase the likelihood of vaginal birth within 24 hours and may reduce the chance of needing a cesarean section. The main risk is overstimulation of the uterus, where contractions come too frequently or too strongly, which can cause the baby’s heart rate to drop temporarily.
Synthetic Oxytocin
Synthetic oxytocin is given through an IV and directly stimulates uterine contractions. It’s often used after the cervix has already been ripened, either naturally or with prostaglandins. The dose is gradually increased until contractions fall into a regular, effective pattern. This is the method most people picture when they think of being “induced.”
Balloon Catheter
A small catheter with an inflatable balloon is inserted through the cervix. The balloon is filled with saline to apply gentle, steady pressure, which mechanically stretches the cervix. This stretching triggers the release of your body’s own prostaglandins from the surrounding tissue, encouraging the cervix to soften and dilate. It’s a drug-free option that works well for cervical ripening and is often used in combination with other methods.
Why Timing Matters
The American College of Obstetricians and Gynecologists is clear that elective induction should not happen before 39 weeks of pregnancy. Babies born at or after 39 weeks have significantly better health outcomes than those born earlier. Before 39 weeks, the lungs, brain, and liver are still undergoing important final development. Medical induction before this point is reserved for situations where continuing the pregnancy poses a greater risk than early delivery.
Signs of Too Many Contractions
Whether you’re using natural or medical methods, it’s possible to overstimulate the uterus. Contractions that come more frequently than every two minutes, last longer than 90 seconds, or don’t allow the uterus to fully relax between them can reduce blood flow to the baby. If you’re attempting natural methods at home and notice contractions that feel relentless with no break, or if you experience severe abdominal pain, stop what you’re doing. With medical induction, providers monitor contraction patterns and fetal heart rate continuously and can adjust or stop medications if the uterus is being pushed too hard.