MiraLAX, an over-the-counter laxative, is considered safe for short-term use during pregnancy. It’s often a first choice for doctors for easing constipation during pregnancy.

Constipation and pregnancy often go hand-in-hand. As your uterus grows to make room for your baby, it puts pressure on your intestines. This makes it harder for you to have normal bowel movements.

Constipation and pregnancy

Constipation can also occur due to hemorrhoids, iron supplements, or injury during childbirth. It’s more likely to occur in the later months of pregnancy, but constipation can happen at any time during pregnancy. This is because increased hormone levels and prenatal vitamins that contain iron can also play a role in making you constipated.

MiraLAX is an OTC medication used to relieve constipation. This drug, known as an osmotic laxative, helps you have bowel movements more often. Here’s what you need to know about the safety of using MiraLAX during pregnancy, including possible side effects.

Is MiraLAX safe to take during pregnancy?

MiraLAX contains the active ingredient polyethylene glycol 3350. Only a small amount of the drug is absorbed by your body, so MiraLAX is considered safe for short-term use during pregnancy. Actually, MiraLAX is often a first choice for doctors for easing constipation during pregnancy, according to one source in American Family Physician.

However, there haven’t really been that many studies on MiraLAX use in pregnant women. For this reason, some doctors may suggest using other drugs that have more research backing their use during pregnancy. These other options include stimulant laxatives such as bisacodyl (Dulcolax) and senna (Fletcher’s Laxative).

Before you use any medication for constipation during pregnancy, talk to your doctor, especially if your constipation is severe. Your doctor may need to check if there’s another problem causing your symptoms.

Learn more: Other causes of constipation »

Side effects of MiraLAX

When used at regular doses, MiraLAX is considered well-tolerated, safe, and effective. Still, like other medications, MiraLAX can cause side effects in some people.

The more common side effects of MiraLAX include:

  • stomach discomfort
  • cramping
  • bloating
  • gas

If you take more MiraLAX than the dosage instructions recommend, it may give you diarrhea and too many bowel movements. This could lead to dehydration (low fluid levels in the body). Dehydration can be dangerous for both you and your pregnancy. For more information, read about the importance of hydration during pregnancy. Be sure to follow the dosage instructions on the package carefully, and if you have questions about dosage, ask your doctor.

Alternatives to MiraLAX

While MiraLAX is considered safe and effective for treating constipation during pregnancy, it’s normal to have concerns about how any drug can affect you or your pregnancy. Keep in mind, medications aren’t the only way to deal with constipation. Lifestyle changes can reduce your risk of constipation and increase how often you have bowel movements. Here are some helpful changes you can make:

  • Drink plenty of fluids, especially water.
  • Eat foods high in fiber. These include fruits (especially prunes), vegetables, and whole-grain products.
  • Get regular exercise, but be sure to talk to your doctor before you increase your activity level during pregnancy.
  • If you’re taking an iron supplement, ask your doctor if you can take less iron or take it in smaller doses.

There are also other OTC laxative drugs that are safe to use during pregnancy. They include:

  • dietary supplements such as Benefiber or FiberChoice
  • bulk-forming agents such as Citrucel, FiberCon, or Metamucil
  • stool softeners such as Docusate
  • stimulant laxatives such as senna or bisacodyl

Talk to your doctor before using any of these products.

Talk with your doctor

While MiraLAX is a safe and effective option for treating constipation during pregnancy, you should talk to your doctor before using it. Consider asking your doctor these questions:

  • Should I take MiraLAX as a first treatment for constipation, or should I try lifestyle changes or other products first?
  • How much MiraLAX should I take, and how often?
  • How long should I use it for?
  • If I still have constipation while using MiraLAX, how long should I wait to call you?
  • Can I take MiraLAX with other laxatives?
  • Will MiraLAX interact with any other medications I’m taking?


Is it safe to take Miralax while breastfeeding?

Anonymous patient


Miralax is considered safe to take if you’re
breastfeeding. At normal doses, the medication does not pass into breast milk.
That means that Miralax likely will not cause side effects in a child who is
breastfed. Still, be sure to talk to your doctor before taking any drugs,
including Miralax, while you’re breastfeeding.

Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.
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