MiraLAX Ingredients

People with occasional constipation may benefit from MiraLAX^® (polyethylene glycol 3350). Polyethylene glycol (sometimes called PEG-3350) is the active ingredient in MiraLAX and works by drawing water into the colon, making the stool soft, and increasing the number of bowel movements. MiraLAX will usually cause a bowel movement in one to three days.

Originally, this product was available by prescription only. In fact, a generic version of MiraLAX is still available as a prescription medication. The prescription version is exactly the same as the over-the-counter (OTC) version, but is more likely to be covered by insurance.

Although most generic medications contain different inactive ingredients than the brand-name drug, generic MiraLAX does not contain any inactive ingredients. Therefore, the generic versions are considered equivalent to the brand-name drug.

(For more information on the ingredients in this laxative, click MiraLAX. This Web resource provides important information on some general safety concerns to be aware of before using this medicine, including possible side effects and dosing instructions.)

List of references (click here)

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

Last reviewed by: Kristi Monson, PharmD