Can I Take MiraLAX While Pregnant?

Woman with a stomach ache

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Despite being a joyful and exciting time, pregnancy comes with its fair share of discomforts and health woes, one of the most common of which is constipation. In fact, 75% of people experience some sort of GI disorder during their first trimester, which can be annoying at best and debilitating at worst.

There are multiple options at the drugstore for treating constipation and other digestive issues, one of which is MiraLAX (polyethylene glycol 3350). When choosing what to grab during pregnancy, experts give MiraLAX the green light.

“MiraLAX is considered safe to take during pregnancy by the American Gastroenterological Association," says Sarah McBane, PharmD, the Associate Dean of Pharmacy Education at UC Irvine School of Pharmacy and Pharmaceutical Sciences. Here, we discuss what to expect when taking it along with a few precautions to keep in mind.

What Is MiraLAX?

MiraLAX is an over-the-counter (OTC) medication used to treat constipation. “It is an osmotic laxative, which means that it works by drawing water into the colon,” explains Dr. McBane. “This helps soften the stool and makes it easier to pass the stool.”

MiraLAX comes in both a liquid, which you mix into four to eight ounces of hot or cold liquid and drink, and a powder, which you also mix into your favorite beverage. You typically need to take it for one to three days before having a bowel movement.

Is It Safe to Take MiraLAX During Pregnancy?

MiraLAX can be a helpful solution for constipation while you’re expecting. Indeed, the American Gastroenterological Association considers it the first-choice laxative for people who are pregnant.

“Generally, it is safe,” concurs Nathan Fox, MD, OBGYN, a maternal-fetal medicine specialist and host of the Healthful Woman podcast. “But it is not the first general treatment I recommend because it can cause abdominal cramping and sometimes diarrhea. I usually recommend dietary modifications first. A terrific option is a glass of prune juice every day.”

Dr. McBane agrees. “Pregnant individuals should always try non-medication measures first,” she says. “These include increasing intake of fluids and dietary fiber as well as exercise. MiraLAX can be used if these strategies are not working to relieve constipation." 

Every pregnancy is different. Be sure to consult with a healthcare provider about your circumstances if you have any questions about taking MiraLAX while pregnant.

What If I Take MiraLAX Before Realizing I’m Pregnant?

Since MiraLAX is a safe way to treat constipation during pregnancy, you won’t run into any problems if you take it before realizing you’re pregnant. “The active ingredient in MiraLAX is minimally absorbed by the body, therefore very little of the medication will be passed on to a fetus,” explains Dr. McBane.

That means that whether or not you know you have a little one on the way, a few days of MiraLAX are A-OK.

Why Constipation Happens During Pregnancy

As mentioned above, constipation is one of the most common symptoms people experience during their first trimester of pregnancy and there are a couple of different causes. For people who didn't suffer from constipation prior to becoming pregnant, their newfound feelings of being blocked up are likely due to hormonal changes.

At the start of a pregnancy, levels of the hormone progesterone increase, which relaxes the intestinal muscles. That means these muscles are not contracting as powerfully, so the movement of food and waste through the digestive tract slows down. The result: things can get backed up.

Constipation during trimester one may also be the result of iron supplementation. When you're pregnant, your iron needs increase by 50%—you need to increase your blood volume and your baby needs iron to facilitate healthy cell growth. But taking an iron supplement can cause constipation, so if your symptoms become unbearable you may need to switch to a different prenatal vitamin and/or strive to reach your increased iron needs through diet instead.

Safety Precautions

Even though MiraLAX is safe to take while you’re pregnant and is generally considered to be a safe and well-tolerated medication, there are still general precautions to be aware of. Dr. McBane notes that MiraLAX can cause gas and bloating, both of which are also common during pregnancy and may be made worse. Other additional symptoms may include nausea, cramping, diarrhea, and hives.

While incredibly rare, some people are allergic to polyethylene glycol (the active ingredient in MiraLAX), and reactions can be severe.

You don’t need to worry about MiraLAX becoming a habit-forming laxative. Since it does not impact the muscles of the gut (like a stimulant laxative does), your body cannot form a dependence on it.

Pregnancy Safe Alternatives

While MiraLAX is safe to take during pregnancy, experts recommending trying these natural strategies first to curb constipation.

Drinking Water

Dr. Fox recommends increasing your fluid intake as a first line of defense against constipation. Simply drinking enough water on a daily basis will increase the frequency of your bowel movements and make them easier to pass.

If you prefer sparkling to plain water, choose a carbonated mineral water, which has been shown to improve stool consistency and frequency in people with constipation.

Eating High-Fiber Foods

Upping your fiber intake is one of the most well-known solutions for increasing the regularity of your bowel movements and improving constipation—and it can also be effective during pregnancy.

Dr. Fox suggests eating cereal with bran as well as high-fiber fruits and vegetables, such as raspberries, apples, mangoes, carrots, beets and broccoli, on a daily basis.

Moving More

To prevent constipation, especially in pregnancy, you need to make sure that the muscles responsible for moving food and waste through your GI tract are strong and toned. And just like the muscles in your legs and arms, they stay strong through regular exercise. So even if your morning sickness has you glued to the sofa or spending time on the bathroom floor, moving around as much as possible will help ease this particular symptom.

A Word From Verywell

Countless people experience constipation during their pregnancy, especially during their first trimester. If natural solutions like increasing fiber intake and moving more are not helping, MiraLAX can be a safe and effective strategy to help ease this common pregnancy-induced digestive woe. Still, you should speak with your OBGYN, midwife or healthcare provider before taking it, especially if you’re taking other medications.

8 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Alyssa Sybertz
Alyssa has been writing about health and wellness since 2013. Her work has appeared in print in publications like FIRST for Women, Woman's World, and Closer Weekly and online at places like,, and She is the author of The OMAD Diet and has served as editor-in-chief for two magazines about intermittent fasting.