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When is the best time to take MiraLAX?

Medically reviewed by Leigh Ann Anderson, PharmD. Last updated on June 21, 2022.

Official answer


For relief of constipation, you can take one dose of MiraLAX at any time of the day for up to 7 days. You may prefer to take it early in the day so that it’s less likely you will have a bowel movement during bedtime or late at night. MiraLAX usually produces a bowel movement in 1 to 3 days.

You may start taking MiraLAX at the first signs of constipation and continue taking one dose per day until you experience relief (up to 7 days maximum or as directed by your doctor).

How fast does Miralax work?

When used as directed for constipation, MiraLAX should produce a bowel movement in 1 to 3 days without harsh side effects. It does not typically cause a sudden feeling of urgency like some other laxatives.

Contact your doctor if you have used MiraLAX for 7 days and still have not had a bowel movement. Do not use MiraLAX for more than 7 days without your doctor’s approval.

What kind of laxative is Miralax?

MiraLAX is an osmotic laxative that contains polyethylene glycol 3350. It works three ways to help treat constipation:

  • It binds and retains water in your colon to help soften your stools.
  • It binds with the stool and water to increase stool volume.
  • It promotes gentle movements with fewer harsh side effects like cramping or bloating.

Be sure to ask your doctor or pharmacist to check for any drug interactions with MiraLAX if you take other prescription or OTC medicines, herbals, vitamins or dietary supplements.

MiraLAX, made by Bayer Healthcare, is available over-the-counter (OTC) without a prescription at your pharmacy, grocery store or online. Generic or store brands are also available for cost savings.

Can I mix MiraLAX with hot coffee?

MiraLAX comes as an unflavored powder that you mix with 4 to 8 ounces of liquid and drink. You can mix it with hot, cold, or room temperature beverages, such as hot or iced coffee, water, apple or orange juice, soda or tea. Stir the mixture fully and drink it right away. Just be sure the powder is completely dissolved before drinking. Do not save it for later use.

Is MiraLAX a gentle laxative?

In general, MiraLAX causes less gas, bloating, or stomach cramping compared to fiber laxatives, stimulant laxatives or stool softeners. You still may have loose, watery or more frequent stools while using this product, but this typically does not occur suddenly.

This product can be used in people 17 years of age and older. For younger children, ask your doctor before using this product.

Ask your doctor before using MiraLAX if you have a bowel obstruction or intestinal blockage, any eating disorder, kidney disease, irritable bowel syndrome, rectal bleeding, nausea or vomiting, stomach pain, or a sudden change in bowel habits.

Do not use MiraLAX if you are allergic to polyethylene glycol.

Related: MiraLAX side effects (in more detail)

This is not all the information you need to know about MiraLAX (polyethylene glycol 3350) for safe and effective use and does not take the place of your doctor’s directions. Review the full product information and discuss this information and any questions you have with your doctor or other health care provider.


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