Most laxatives are considered safe during pregnancy. They have minimal systemic absorption, meaning very little enters your bloodstream or reaches the baby. That said, not all types carry the same level of reassurance, and some are better first choices than others.
Constipation affects a large percentage of pregnant women, thanks to hormonal shifts that slow digestion and the physical pressure of a growing uterus on the bowels. Knowing which options are safe, which to use cautiously, and which to avoid can save you a lot of unnecessary worry.
Why Constipation Is So Common in Pregnancy
Progesterone, the hormone that rises sharply to support pregnancy, relaxes smooth muscle throughout your body. That includes the muscles of your intestines, which means food moves through your digestive tract more slowly. The result is harder, drier stools that are more difficult to pass. Iron supplements, which many pregnant women take, can make things worse.
As pregnancy progresses, the uterus physically compresses the bowel, further slowing things down. This is why constipation often worsens in the second and third trimesters, even if your diet hasn’t changed.
Lifestyle Changes to Try First
Before reaching for a laxative, simple adjustments can make a real difference. The Cleveland Clinic recommends eating 25 to 30 grams of fiber-rich foods each day. Whole grains, fruits, vegetables, beans, and lentils all count. Fiber softens stool by drawing water into it, making it easier to pass.
Hydration matters just as much. Aim for 8 to 12 cups of water daily. Eight cups is the bare minimum during pregnancy because your body needs extra fluid to support the pregnancy itself, and that extra fluid also helps keep stool soft. Water is ideal, but other beverages count too. Regular physical activity, even a daily walk, helps stimulate the bowel and can reduce constipation significantly.
Bulk-Forming Laxatives: The Safest First Choice
Bulk-forming laxatives like psyllium (Metamucil) and methylcellulose (Citrucel) are the most commonly recommended option for pregnant women. They work by absorbing water in the gut and adding bulk to stool, essentially doing what dietary fiber does but in a more concentrated form.
These products are not absorbed into the body at all, which means they don’t enter your bloodstream or cross the placenta. Surveillance data on psyllium use during the first trimester found no increased risk of birth defects. Because of this safety profile, bulk-forming laxatives are considered safe for long-term use throughout pregnancy. They do take 12 to 72 hours to work, so they’re not a quick fix. Drink plenty of water with them to avoid making constipation worse.
Stool Softeners
Stool softeners like docusate sodium (Colace) are another widely used option during pregnancy. They work by allowing water and fats to penetrate stool, making it softer and easier to pass. Like bulk-forming laxatives, docusate has minimal systemic absorption and is not expected to increase the risk of birth defects.
Many prenatal care providers recommend stool softeners as a first-line option, particularly after delivery or for women taking iron supplements. They’re gentle, but they’re also relatively mild. If your constipation is more severe, a stool softener alone may not be enough.
Osmotic Laxatives
Osmotic laxatives, including polyethylene glycol (MiraLAX) and lactulose, work by pulling water into the intestines to soften stool and stimulate a bowel movement. They are poorly absorbed into the bloodstream and are generally considered safe during pregnancy.
Polyethylene glycol is one of the more commonly used options when fiber and stool softeners aren’t doing enough. It’s tasteless, mixes into any liquid, and typically produces results within one to three days. It’s not meant for daily long-term use without guidance from your provider, but occasional use is well tolerated.
Stimulant Laxatives: Use With Caution
Stimulant laxatives like senna (Senokot) and bisacodyl (Dulcolax) cause the intestinal muscles to contract, pushing stool through more quickly. They work faster than other options, often within 6 to 12 hours.
These also have minimal systemic absorption, and available data does not link them to an increased risk of birth defects. However, they’re typically reserved for short-term or occasional use when gentler options haven’t worked. The concern with regular use isn’t about harm to the baby but about the possibility of cramping, diarrhea, or electrolyte imbalances in the mother. Prolonged use can also lead to the bowel becoming dependent on stimulation to function normally.
What to Avoid
Castor oil is the one laxative to clearly steer away from during pregnancy. It has a well-documented ability to trigger uterine contractions, which is why it has historically been used (and studied) as a method of labor induction. In clinical studies, castor oil induced labor onset in roughly 47 to 54% of women at term, compared to only about 4 to 7% in control groups. It also commonly causes nausea and severe diarrhea, with nausea rates reaching 48% in one study. Using it before your due date could potentially contribute to preterm labor.
Mineral oil is another product best avoided. It can interfere with the absorption of fat-soluble vitamins (A, D, E, and K), which are critical during pregnancy for both your health and the baby’s development. If aspirated, it can also cause a type of pneumonia, though this risk is small.
Choosing the Right Approach
A practical starting point looks like this: increase fiber intake to 25 to 30 grams per day, drink at least 8 to 12 cups of water, and stay active. If that’s not enough after a few days, a bulk-forming laxative or stool softener is a reasonable next step. If constipation persists, an osmotic laxative like polyethylene glycol is the typical escalation. Stimulant laxatives are a last resort for occasional use when nothing else has worked.
Signs That Need Medical Attention
Most pregnancy constipation is uncomfortable but manageable. However, certain symptoms alongside constipation warrant a call to your provider: rectal bleeding or bloody stools, significant abdominal pain or cramping, dizziness or lightheadedness, dark urine or very little urine output (a sign of dehydration), or an inability to keep down fluids. Diarrhea that develops suddenly in combination with low back pain and increased vaginal discharge can be a sign of preterm labor and needs immediate evaluation.