Miralax Powder: Uses, Dosage, Side Effects, Precautions and Alternates

Quick overview

Miralax Powder (polyethylene glycol 3350) is a brand-name, over-the-counter osmotic laxative used to treat occasional constipation. It comes as a powder that is mixed with a drink before taking and does not require a prescription. It is intended for adults and adolescents ages 17 and older, with use in younger children only under a doctor's direction. It typically produces a bowel movement within 1 to 3 days.

What is Miralax Powder

MiraLAX is a brand-name, over-the-counter medicine used to treat occasional constipation. It comes as a powder that you mix with a drink before taking it, and you do not need a doctor's prescription to buy it.

Miralax Powder uses

• Treating occasional constipation in adults and adolescents ages 17 and older
• Bowel preparation and other uses as directed by a doctor in children, under medical supervision

Benefits of Miralax Powder

• Usually produces a bowel movement within 1 to 3 days
• Works gently, without the sudden urgency or cramping some other laxatives can cause
• Dissolves fully in a drink and has no added taste or grit

How Miralax Powder works

MiraLAX is not absorbed into your bloodstream. Instead, it holds onto water as it passes through your gut and brings that water into your colon, which softens your stool and helps you have more regular bowel movements.

Miralax Powder dosage

Measure your dose using the marked cap on the bottle, or use a single-serve packet. Stir the powder into a beverage such as water, juice, soda, coffee, or tea — it can be cold, hot, or room temperature. Stir well until the powder is completely dissolved and there are no clumps left before drinking. Drink the whole glass right away rather than sipping it over time.

Do not mix MiraLAX with starch-based thickeners used for swallowing difficulties. You can take it with or without food, and at any time of day, though morning may be preferred so any bowel movement happens during the day. Take it only once per day unless a doctor tells you otherwise, and do not use it for more than 7 days in a row without talking to a doctor.

This product is meant for adults and adolescents ages 17 and older; for children 16 and under, ask a doctor first.

Available forms and strengths

• Powder (mixed with liquid before taking)

Side effects of Miralax Powder

Common

• Gas
• Bloating
• Mild upset stomach or nausea
• Stomach cramping or pain
• Loose or watery stools
• Dizziness
• Increased sweating

Serious

• Severe or watery diarrhea that does not stop
• Rectal bleeding or blood in stools
• Nausea, bloating, cramping, or stomach pain that gets worse
• Signs of dehydration such as dizziness, extreme thirst, or a faster heartbeat
• Signs of an allergic reaction such as rash, hives, or itching
• Severe allergic reaction with swelling of the face, lips, tongue, or throat, or trouble breathing
• Signs of a possible bowel blockage, such as severe abdominal pain

Warnings and precautions

• Do not use MiraLAX if you have a bowel blockage or intestinal obstruction, or if you have kidney disease, unless your doctor says it's okay — these conditions can lead to dangerous side effects.
• People with eating disorders such as anorexia or bulimia should not use MiraLAX without a doctor's guidance.
• Do not use MiraLAX if you are allergic to polyethylene glycol.
• Do not use MiraLAX for more than 7 days in a row; see a doctor if constipation continues.
• MiraLAX may make other oral medicines less effective by speeding up how fast things move through your intestines, so check with a doctor or pharmacist if you take other prescription drugs.
• Do not combine MiraLAX with starch-based thickeners used for swallowing difficulties.
• It is not known whether MiraLAX could harm an unborn baby, so tell your doctor if you are pregnant or planning to become pregnant before using it. It isn't known whether MiraLAX passes into breast milk or could affect a nursing baby, so tell your doctor if you are breastfeeding.
• People with kidney disease should not use MiraLAX unless a doctor says it's okay and supervises its use, since it can affect the body's salt and mineral balance.
• Alcohol may contribute to digestive problems, so it may help to limit it while dealing with constipation.

Storage

• Store at room temperature away from moisture and heat.
• Keep out of reach of children.
• In case of overdose, get medical help or contact a poison control center right away.

When to see a doctor

• Get emergency help right away if you have signs of a severe allergic reaction, such as hives, difficulty breathing, or swelling of your face, lips, tongue, or throat.
• Stop taking MiraLAX and call your doctor right away if you have diarrhea (including severe or bloody diarrhea), rectal bleeding, blood in your stools, or worsening nausea, bloating, cramping, or stomach pain.
• Call a doctor if you still need a laxative after using it for more than 7 days in a row.
• If you feel dizzy, extremely thirsty, or notice a fast heartbeat with ongoing diarrhea, contact a doctor right away, as this can mean dehydration.
• If your symptoms feel life-threatening or you think you're having a medical emergency, get emergency help right away.

Alternatives

• Docusate
• Bisacodyl
• Lactulose