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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)
    Kristalose (lactulose)
  • Polyethylene glycol (Miralax)
    Kristalose (lactulose)

  • Summary of Miralax vs. Kristalose

    Summary for Osmotic laxative

    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.

    Summary for Osmotic laxative
    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 of Miralax vs. Kristalose

    Indications for
    •Occasional constipation and irregular bowel movements
    Indications for
    •Constipation

  • Pros and Cons of Miralax vs. Kristalose

    Pros and Const for Osmotic laxative
    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
    Pros and Const for Osmotic laxative
    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
    •Not appropriate for people on a low-galactose diet
    •Not a first-choice laxative because of the side effects
    •Need to mix with water, so can be inconvenient

  • Common Side Effects of Miralax vs. Kristalose

    Common Side Effects for
    •Nausea
    •Passing gas
    •Bloating
    Common Side Effects for
    •Flatulence or passing gas
    •Stomach cramps

  • Warnings of Miralax vs. Kristalose

    Common Side Effects for
    •Complete or partial blockage of intestines
    Common Side Effects for
    •Loss of fluids
    •Possible risk of high blood sugar
    •Problems during colonoscopy

  • Prices with our coupons for Miralax vs. Kristalose

    Learn more about Polyethylene glycol
    Learn more about Kristalose

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