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Dec 04, 2023

The Differences Between Metamucil and Miralax

Metamucil and Miralax are both over-the-counter (OTC) medicines used to treat constipation. However, Metamucil and Miralax work differently and have different side effects and safety profiles. The

Metamucil and Miralax are both over-the-counter (OTC) medicines used to treat constipation. However, Metamucil and Miralax work differently and have different side effects and safety profiles.

The following is a comparison of these medications.

The Food and Drug Administration (FDA) has received several reports of adverse events in children taking polyethylene glycol (PEG) products, such as Miralax. The FDA has conducted a review that documented several reports of neurological and psychiatric events associated with chronic (long-term) use of these medicines in children. Some of these children received an adult dose of PEG (17 grams) for an extended period.

The North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition (NASPGHAN) recommends that parents discuss Miralax use with their child's healthcare provider, who can weigh the risks and benefits of treatment with Miralax and give personalized medical advice.

Metamucil is a fiber laxative. The active ingredient is called psyllium husk powder. Its primary use is to relieve occasional constipation (irregularity). A dose of Metamucil usually produces a bowel movement in 12 to 72 hours. It can also be a fiber supplement to maintain regular bowel movements.

Metamucil may also reduce the following:

Additionally, some studies show that taken regularly, Metamucil may help lower the following:

Metamucil is a bulk-forming laxative. It works by:

Metamucil is available over the counter in brand-name and generic products, and it's sold in various forms like powders, granules, capsules, liquids, and wafers.

Miralax is classified as an osmotic laxative. The active ingredient is called polyethylene glycol (PEG) 3350.

PEG works by doing the following:

Miralax generally produces a bowel movement in one to three days. It is sometimes used in people with fecal impaction (stool stuck in the colon or rectum).

Some healthcare providers recommend Miralax as a bowel-cleansing agent before a procedure like a colonoscopy.

In some cases, healthcare providers also recommend Miralax for people with the following:

Miralax is available over the counter in brand-name and generic products. It comes in a powder form; the powder is mixed with liquids, and the individual drinks it.

Miralax is available in the following:

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Both OTC medications can be effective at treating constipation.

The medications have not been studied directly against each other in clinical trials.

The American Society of Colon and Rectal Surgeons' Clinical Practice Guideline for the Evaluation and Management of Constipation recommends initially managing constipation with dietary modifications, including fiber supplements like Metamucil.

The guidelines also state that an osmotic laxative like Miralax is a safe and appropriate treatment for chronic (ongoing) constipation.

Check with your healthcare provider for medical advice on whether Metamucil or Miralax would be more appropriate for you.

Advantages of Metamucil include the following:

Advantages of Miralax include the following:

Disadvantages of Metamucil include the following:

Disadvantages of Miralax include the following:

There are some lifestyle changes you can try to help improve constipation symptoms, such as:

Some research supports the use of probiotics,

Talk to your healthcare provider about other options to help with constipation.

Consult a registered dietitian nutritionist (RDN) who can help you or your child find ways to incorporate more fiber into the diet.

Common side effects of Metamucil include the following:

Common side effects of Miralax include the following:

Metamucil and Miralax may cause other side effects. Call your healthcare provider if you have unusual problems while taking one of these medications. If you experience a severe side effect, you or your provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088). If you have any urgent side effects like severe diarrhea, difficulty breathing, or swelling of the face, lips, tongue, or throat, get emergency medical help.

Precautions for Metamucil or Miralax medications should be considered.

If you are pregnant, planning to become pregnant, or are breastfeeding, consult your healthcare provider before using Metamucil or Miralax.

Metamucil precautions include the following:

Miralax precautions include the following:

You should not take Metamucil if:

Avoid Miralax in the following circumstances:

Metamucil may affect how other medications are absorbed. Therefore, take Metamucil at least two hours before or after any other oral medications.

Miralax may affect how other medicines are absorbed. Therefore, take Miralax at least one hour before or after any other oral medications.

Consult with your healthcare provider for more information about drug interactions and how they may affect you.

Metamucil and Miralax are over-the-counter medications used to relieve constipation. Metamucil is a bulk-forming laxative that contains psyllium, a soluble fiber. It helps constipation and, taken regularly, may have other benefits, such as lowering blood sugar and cholesterol. Miralax is an osmotic laxative that contains polyethylene glycol.

If you have any questions or concerns or are unsure if one of these medications is appropriate for you, reach out to your healthcare provider.

Probably not. Although these medications do not chemically interact, it's best to check with a healthcare provider before taking more than one medication that treats constipation.

Metamucil and Miralax have several differences. For example, Metamucil is available in many dosage forms. It is a bulk-forming laxative that contains a fiber called psyllium. Miralax is a powder that can be dissolved in any beverage. It's an osmotic laxative that contains polyethylene glycol.

No. Although they both treat constipation, Metamucil and Miralax are not the same. They are different types of laxatives, work differently, and have different safety profiles.

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By Karen Berger, PharmDKaren Berger, PharmD, is a community pharmacist and medical writer/reviewer.