MiraLAX is an over-the-counter drug that works to treat constipation by drawing water into your colon, softening your stool and making it easier to pass. Your response to this drug may vary based on your medical history and diagnosis.
MiraLAX is a brand-name medication used to treat constipation in people ages 17 years and older. It comes as a powder you mix with liquid to make an oral solution.
MiraLAX (polyethylene glycol 3350) belongs to a class of medications called osmotic laxatives. These drugs work (their mechanism of action) by drawing water into your colon (large intestine) from surrounding tissues. This softens your stool and may naturally stimulate your colon to contract, which helps ease bowel movements.
MiraLAX doesn’t typically cause a bowel movement right after you take it. It generally takes 1 to 3 days to work when taken for constipation.
Note: When used for colonoscopy bowel prep, MiraLAX is taken in much larger doses and in combination with other laxatives. So, the effects will be quicker and cause diarrhea. For more information about this use of MiraLAX, check out the “Colonoscopy prep” section of this MiraLAX overview article.
Talk with your doctor or pharmacist if you have other questions about how MiraLAX works to treat constipation.
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