How Does MiraLAX Work?

Interested in a Discount on MiraLAX?

MiraLAX^® (polyethylene glycol 3350) is an over-the-counter (OTC) laxative medication used to treat occasional constipation. Like all OTC medications, it is available without a prescription. But how does MiraLAX work to relieve constipation?

The active ingredient in MiraLAX is polyethylene glycol 3350 (sometimes abbreviated as PEG-3350), which is an osmotic laxative. This drug works by drawing water into the colon, softening the stool, and increasing the frequency of bowel movements. MiraLAX will usually cause a bowel movement in one to three days.

The product comes as a powder, which is dissolved in four to eight ounces of liquid and swallowed by mouth. It is usually used once a day. If you do not have a bowel movement right away, do not take more than the standard dosage. Also, do not use this medication for more than seven days unless a healthcare provider tells you to do so.

(For more information on how this laxative works, click MiraLAX. This article offers a complete overview of this medication, including potential side effects, dosing guidelines, and safety precautions.)

List of references (click here)

Written by/reviewed by: Susan Lakey, PharmD, MPH

Last reviewed by: Kristi Monson, PharmD