Skip to main content

Compare
Miralax vs. Kristalose

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

Key takeaways

Polyethylene glycol 3350 (Miralax) and lactulose (Constulose, Kristalose) are both osmotic laxatives used to treat constipation, but they have some key differences. Miralax is available over-the-counter, while lactulose requires a prescription. Miralax typically causes a bowel movement within 1 to 3 days, whereas lactulose usually works within 2 days. Both medications can cause side effects like gas and bloating. Additionally, lactulose contains sugars like galactose and lactose, which can affect blood sugar levels, making it less suitable for people with diabetes. Miralax, on the other hand, is generally considered safe for people with kidney problems, provided a healthcare professional approves its use.

Polyethylene glycol

(Miralax)

Get free coupons

Kristalose

(lactulose)

Get free coupons

Summary for Miralax

Over-the-counter

Polyethylene glycol (Miralax) is an over-the-counter (OTC) medication used for occasional constipation. It comes as a powder that you need to mix with a beverage and then drink. Typically, you take a dose of polyethylene glycol (Miralax) once a day, for up to a week. Most people will experience a bowl movement in 1 to 3 days. Some side effects that polyethylene glycol (Miralax) can cause include nausea, bloating, and passing gas.

Indications for Miralax

Pros and Cons for Miralax

Pros

  • Available OTC, so you don't need a prescription from your provider
  • Causes less cramping, bloating, gas, or feelings of "having to go right now" compared to other laxatives
  • A possible option during pregnancy, if provider says it's safe for you to take

Cons

  • Can take a few days before you have a bowel movement
  • Only for short-term relief of constipation
  • Might cause loose, watery stools

Common Side Effects for Miralax

Warnings for Miralax

  • Complete or partial blockage of intestines

Summary for Kristalose

Prescription only

Kristalose (lactulose) is an osmotic laxative. It's used to help relieve constipation in adults. Kristalose (lactulose) comes as a powder packet with 10 grams of lactulose per packet. The usual dosage is to dissolve 1 to 2 packets of Kristalose (lactulose) in water and to take by mouth daily. After you start treatment, it can take up to two days before you have a bowel movement. Some common side effects of Kristalose (lactulose) include stomach cramps and passing gas.

Indications for Kristalose

Pros and Cons for Kristalose

Pros

  • Comes as convenient single-dose packets
  • Might be a good option for people with constipation who didn’t see benefits with OTC laxatives
  • Typically taken once daily

Cons

Common Side Effects for Kristalose

  • Flatulence or passing gas
  • Stomach cramps

Warnings for Kristalose

  • Loss of fluids
  • Possible risk of high blood sugar
  • Problems during colonoscopy

Prices with our coupons for Miralax vs. Kristalose

Price Card Drug Icon
Polyethylene Glycol 3350 Non-Prescription1 bottle / 30 doses of 17g/dose
$19.32$26.12
Get free coupons
More Information
Price Card Drug Icon
Kristalose1 carton / 30 packets of 20g
$107.97$393.78
Get free coupons
More Information

Compare other Constipation drugs

Golytely vs. MiralaxLactulose vs. MiralaxMagnesium-citrate vs. MiralaxMiralax vs. ColaceMiralax vs. Dok-plus
Miralax vs. KristaloseMiralax vs. LinzessMiralax vs. SennaMovantik vs. MiralaxMoviprep vs. MiralaxSuprep vs. MiralaxTrilyte vs. MiralaxColace vs. MovantikDulcolax vs. Magnesium-citrateFibercon vs. Magnesium-citrateFibercon vs. SennaGolytely vs. Magnesium-citrateLactulose vs. SennaLinzess vs. MovantikMagnesium-citrate vs. Dok-plusMagnesium-oxide vs. Magnesium-citrateMagnesium-sulfate vs. Magnesium-citrateMilk-of-magnesia vs. Magnesium-citrateMovantik vs. DulcolaxMovantik vs. Magnesium-citrateMovantik vs. SennaMovantik vs. Senna-sMoviprep vs. Magnesium-citrateRelistor vs. MovantikSenna-s vs. Senna

Browse medications by letter

Show All

Browse prescription and over-the-counter medications from A to Z, compare drug prices, and start saving.