Compare lactulose vs. Miralax

Head-to-head comparisons of medication uses, side effects, ratings, and more.

Generlac
(Lactulose)

Miralax
(Polyethylene Glycol)

Coming soon.Helps get things moving. Miralax (Polyethylene Glycol) provides effective relief of constipation without "cramping" your style.
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Reviews & ratings
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Reviews for Miralax (Polyethylene Glycol)
74%
26% vs. Generlac (Lactulose)
54%
46% vs. Generlac (Lactulose)
10%
10% vs. Generlac (Lactulose)
Side effects
lactuloseMiralax

We haven’t found good data for lactulose side effects.

FDA side effect reports for lactulose »

The Miralax FDA package insert doesn’t have numbers about how common side effects are.

More about Miralax side effects »
How it works
lactuloseMiralax
Coming soon.Miralax (Polyethylene Glycol) is an osmotic laxative. It uses osmosis to keep more water in your intestine, which softens your stool and makes it easier to pass.
Type of medication
lactuloseMiralax
Coming soon.
Laxative
Osmotic
Over-the-counter
Available as
lactuloseMiralax
  • Liquid
  • Liquid
Used for (click to learn more)
lactuloseMiralax
  • Constipation Hepatic encephalopathy; Treatment and Prophylaxis
Risk factors for serious side effects
lactuloseMiralax
Coming soon.
  • Taking with medications that cause electrolyte imbalance
  • Age 60 or older
  • Women of childbearing age
  • Age 60 or older
  • Malignancy
  • Other condition that causes blockage or narrowing of bowel
  • Taking medications that cause constipation
Detailed Miralax (Polyethylene Glycol) risks & warnings »
Pregnancy category
lactuloseMiralax
BFDA pregnancy category (Probably safe)

Research studies with animals haven’t found a risk to unborn babies, but it hasn’t been properly studied in humans.

See the FDA package insert
CFDA pregnancy category (Weigh risks vs. benefits)

Research studies with animals found harmful effects on unborn babies. It hasn’t been properly studied in humans. The benefits might outweigh the risks even if you’re pregnant. Talk with your doctor.

See the FDA package insert
Alcohol
No specific alcohol-related info.No specific alcohol-related info.
Food
No specific food-related info.
  • Talk to you doctor about eating certain foods and getting more exercise to help prevent your constipation.
Kidneys and liver
No specific kidneys and liver-related info.
  • Ask your doctor before you take Miralax if you have nausea or vomiting, irritable bowel syndrome (IBS), kidney disease, or sudden changes in your stool for more than 2 weeks.
Sex
No specific sex-related info.No specific sex-related info.
Sleep
No specific sleep-related info.No specific sleep-related info.
Weight
No specific weight-related info.No specific weight-related info.
Upsides and benefits
lactuloseMiralax
Coming soon.
  • Miralax is the most recommended laxative by pharmacists and doctors.
  • Most people felt it was worth the hassle.
  • It's gluten and sugar free.
  • It causes little to no cramping, bloating, gas, or feelings like you "have to go right now" compared to some other medicines to treat constipation.
  • Works differently than other over-the-counter laxatives so it's a great alternative if other medicines haven't worked.
Downsides and risks
lactuloseMiralax
Coming soon.
  • You have to dissolve Miralax in a beverage and drink it versus taking a pill.
  • It's not for children 16 years or younger.
  • Miralax doesn't work overnight. It can take up to 2-4 days to have a bowel movement.
  • It's not recommended that you take it for more than a week, so it you haven't had any success, you'll need to call your doctor for other laxative options.
Tips from our pharmacists for people taking the medication
lactuloseMiralax
Coming soon.
  • Dissolve Miralax powder in 4 to 8 ounces of water, juice or other drink (cold or hot) once a day.
  • Works in about 1 to 3 days. Don't use for more than 1 week.
  • Miralax is available in four different size dose bottles. It also come in pre-measured single-dose packets to make dosing easier or if you travel.
  • Ask your doctor about giving it to anyone younger than 17 years.
  • Doesn't cause as much bloating, cramping or feelings like you "have to go right now" as other medicines to treat constipation.
  • Ask your doctor before you take Miralax if you have nausea or vomiting, irritable bowel syndrome (IBS), kidney disease, or sudden changes in your stool for more than 2 weeks.
  • Stop using Miralax and call your doctor if you have pain, cramping, swelling or bulging in your belly, diarrhea, rectal bleeding or find you need to use for more than 1 week.
  • Talk to you doctor about eating certain foods and getting more exercise to help prevent your constipation.
Learn more
More about lactuloseSide effectsReviews & ratingsFDA package insert
More about MiralaxSide effectsReviews & ratingsAlternativesFDA package insert