Suprep vs Miralax

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For patients dealing with chronic constipation or preparing for colonoscopies, certain medications can help increase the frequency and ease of bowel movements. Suprep and Miralax are two such drugs often recommended in these cases. They each work by drawing water into the intestines to soften stools and stimulate bowel movements. Suprep is a prescription medication primarily used as a bowel prep before a colonoscopy, it contains sodium sulfate, potassium sulfate, and magnesium sulfate which help to clear the bowels effectively but might cause electrolyte imbalance if not taken properly. On the other hand, Miralax is an over-the-counter drug that contains polyethylene glycol 3350 (PEG 3350), promoting increased water content in stool leading to softer stools and easier passage without any significant impact on electrolyte balance.

What is Suprep?

Suprep (generic name sodium sulfate, potassium sulfate, and magnesium sulfate) was a ground-breaking introduction to the class of drugs known as osmotic laxatives. Approved by the FDA in 2010, Suprep is used primarily for bowel preparation ahead of a colonoscopy. It operates by retaining water in the intestinal lumen, which stimulates an increase in peristalsis or bowel movement activity. This process effectively "flushes out" the colon more thoroughly than usual.

On the other hand, Miralax (polyethylene glycol 3350), also an osmotic laxative but available over-the-counter since its approval in 1999, works similarly to Suprep but is generally prescribed for constipation relief rather than extensive cleansing like pre-procedure preparations. Its influence on water retention within stool aids softening it and increases frequency of bowel movements.

Both medications share similar mechanisms; however, Suprep has a stronger effect due to its specific combination of active ingredients resulting in more complete evacuation making it suitable for medical procedures like colonoscopies while Miralax's milder influence makes it appropriate for regular constipation relief with fewer side effects such as bloating or abdominal discomfort.

What conditions is Suprep approved to treat?

Suprep is approved for use as a bowel preparation prior to colonoscopy:

  • Bowel prep before colonoscopy
  • Not intended for use as a laxative

Miralax, on the other hand, is utilized in managing constipation and irregularity:

  • Chronic or occasional constipation
  • Irregular bowel movements

How does Suprep help with these illnesses?

Suprep helps to manage constipation and prepare the bowel for medical procedures by increasing the amount of water in the intestinal tract. It does this by causing a shift of water into the intestine, thereby softening stools and stimulating bowel movements. Water plays an important role in digestion, nutrient absorption, and waste elimination within our body. In cases where individuals suffer from constipation or need bowel preparation before medical procedures like colonoscopy, it is crucial to maintain adequate hydration in the intestines. Therefore, by increasing water content in the intestines, Suprep can efficiently relieve constipation or clear out bowels prior to a procedure which ultimately aids patients manage their condition more effectively.

What is Miralax?

MiraLAX, the brand name for polyethylene glycol 3350, is a laxative solution that increases the amount of water in the intestinal tract to stimulate bowel movements. It operates through an osmotic effect, drawing water into the colon and increasing liquidity and volume of stools, which aids in their passage. First approved by FDA in 1999 as a prescription drug before becoming available over-the-counter in 2006, MiraLAX does not have systemic effects as it's poorly absorbed by the gut. This means side-effects are limited mainly to digestive issues such as bloating or gas. Unlike stimulant laxatives like bisacodyl (found in Suprep), MiraLAX doesn't cause cramping or sudden urgency and so can be preferable for some patients requiring constipation relief or bowel preparation prior to medical procedures.

What conditions is Miralax approved to treat?

Miralax is an over-the-counter medication that's used to treat constipation. It works by holding water in the stool to soften it and increase bowel movements. Miralax is approved for short-term treatment of occasional constipation. Here are some conditions where its use can be beneficial:

  • Occasional bouts of constipation
  • Preparing the bowel before a colonoscopy

How does Miralax help with these illnesses?

Miralax is a type of osmotic laxative that works by drawing water into the intestines, softening stool and making bowel movements easier. This action aids in alleviating constipation symptoms and facilitating regularity. Its active ingredient, polyethylene glycol 3350, is non-systemic and not absorbed by the body, resulting in fewer side effects compared to other medications. While Suprep also helps with bowel preparation before surgery or certain procedures like colonoscopy, it does so through an entirely different mechanism involving sodium sulfate which can lead to dehydration if not properly managed. Miralax's gentle working mechanism may be preferred for patients who cannot tolerate such strong purgatives or have concerns about maintaining hydration levels.

How effective are both Suprep and Miralax?

Both Suprep and Miralax are effective medications for bowel preparation, regularly prescribed prior to colonoscopies. They were approved by the FDA within a few years of each other: Miralax in 1999 and Suprep in 2010. Although both drugs share a common purpose, they function slightly differently and may be recommended under varying circumstances.

Suprep is an osmotic laxative that causes water retention in the stool to stimulate bowel movements, while Miralax also functions as an osmotic laxative but requires additional electrolytes mixed with it (known as Gatorade/Miralax prep). Both medications have been directly compared in clinical trials; one such study conducted in 2013 found no significant difference between the two regarding effectiveness or safety profile. However, patients reported less bloating and nausea when using Suprep compared to those using Miralax/Gatorade mix.

A review of several studies on Suprep highlighted its efficacy at cleansing bowels starting from first use, demonstrated minimal side effects relative to other bowel preps (such as sodium phosphate solutions), and showed good patient tolerance across diverse populations including elderly individuals. As a newer medication with unique features like split-dosing regimen for better compliance and lower volume intake than many alternatives, it has quickly become widely utilized.

Meanwhile, a meta-analysis conducted in 2008 indicated that PEG-based solutions (like Miralax) appear more effective than placebo at preparing bowels for colonoscopy while maintaining similar safety profiles to other commonly-used preparations. Despite these findings, some patients might find consuming large volumes difficult; this can lead practitioners towards recommending alternative options like low-volume agents such as Suprep instead.

abstract image of a researcher studying a bottle of drug.

At what dose is Suprep typically prescribed?

Dosages of Suprep for bowel preparation involve two 6 oz. bottles to be taken orally, typically the evening before and the morning of a colonoscopy. The solution should be diluted with water before consumption. On the other hand, Miralax is often used for relief from occasional constipation with standard doses ranging from 17 g (cap filled to line) mixed in 4–8 ounces of beverage once a day in adults and children over age 17. It can be increased as necessary under doctor supervision up to three times per day but should not exceed seven days usage without physician approval.

At what dose is Miralax typically prescribed?

Miralax treatment is generally started at a dosage of 17 grams (about 1 heaping tablespoon) per day. It can be mixed into any beverage, such as water, coffee, tea or juice. If there is no response to the initial dose after a few days, it may be increased up to twice daily under doctor's advice. The maximum dose for Miralax should not exceed 34 grams (two heaping tablespoons) in a single day unless directed by your healthcare provider. Always remember to drink plenty of fluids when taking this medication as it works by drawing water into the colon from the body tissues surrounding it.

What are the most common side effects for Suprep?

Common side effects that may occur with Suprep include:

  • Bloating
  • Nausea and vomiting
  • Stomach cramps or discomfort
  • Dizziness, lightheadedness, or fainting spells due to dehydration from frequent bowel movements

On the other hand, Miralax has its own set of potential side effects like:

  • Bloating or gas
  • Upset stomach (nausea)
  • Diarrhea or loose stools
  • Increased sweating Again, if you experience severe reactions seek medical attention immediately.

abstract image of a patient experiencing side effect

Are there any potential serious side effects for Suprep?

While Suprep and Miralax are both used to treat constipation, they can have different side effects. For Suprep, more serious but rare side effects include:

  • Signs of allergic reaction: hives; difficult breathing; swelling in your face or throat
  • Severe stomach pain or bloating
  • No bowel movement within two hours after use
  • Dehydration symptoms - dizziness, feeling very thirsty or hot, being unable to urinate, heavy sweating, or hot and dry skin
  • Electrolyte imbalance - increased thirst or urination, confusion, vomiting, constipation

On the other hand for Miralax users should watch out for:

  • Allergic reactions such as rash; itching/swelling (especially of the face/tongue/throat); severe dizziness; trouble breathing.
  • Irregular heartbeat
  • Mood changes
  • Seizures

These could be signs of a serious condition. If you experience any of these symptoms while taking either medication stop using it immediately and seek medical attention promptly.

What are the most common side effects for Miralax?

Miralax, a commonly used laxative, can have an array of side effects, although they tend to be less severe than those associated with Suprep. Some individuals may experience:

  • Bloating or gas
  • Mild stomach discomfort
  • Diarrhea
  • Nausea
  • Headache and dizziness

These side effects are usually temporary and will resolve once your body adjusts to the medication. However, if these symptoms persist or worsen over time, you should seek medical attention immediately.

Are there any potential serious side effects for Miralax?

While Miralax is generally well-tolerated, it can in some cases cause serious side effects. These may include:

  • Severe or bloody diarrhea
  • Unusual bloating or severe stomach pain
  • Allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
  • Signs of dehydration such as feeling very thirsty or hot, being unable to urinate, heavy sweating, or hot and dry skin
  • Blood in your stools
  • Feeling faint

If you experience any of these symptoms after taking Miralax for bowel prep before a colonoscopy procedure (or for any other reason), consult with your healthcare provider immediately. Remember that while rare adverse effects are possible with any medication; they do not occur in everyone who takes the drug.

Contraindications for Suprep and Miralax?

Both Suprep and Miralax, along with most other laxative medications, may cause uncomfortable side effects such as bloating, nausea or stomach cramps in some people. If you notice your discomfort worsening after using these products for bowel preparation or constipation relief, please seek immediate medical attention.

Neither Suprep nor Miralax should be taken if you are currently using drugs that affect kidney function including diuretics (water pills) or certain blood pressure medication. Always inform your healthcare provider about the medications you are taking; these medications might interfere with the effectiveness of both Suprep and Miralax and potentially lead to serious health problems like electrolyte imbalance or dehydration. In particular patients with severe kidney disease need to use caution when considering products like Suprep due to potential accumulation of magnesium in the bloodstream.

How much do Suprep and Miralax cost?

For the brand-name versions of these drugs:

  • The price for a Suprep Bowel Prep kit, which contains two 6 oz bottles, averages around $100. It is used as a one-time prep treatment for colonoscopy procedures.
  • A 30-dose pack of Miralax (17g per dose) costs about $25.

Thus, if you are using these medications in preparation for a procedure like a colonoscopy once or twice a year, then Miralax would be less expensive on an annual basis as it's cheaper per dose and can also be used to treat occasional constipation throughout the year.

It's important to note that cost should not be your primary consideration when deciding between these two medications; instead focus on which medication will best meet your needs based on their efficacy and side effect profiles. As always with medical decisions, consult with your healthcare provider first.

In terms of generic options:

  • Generic polyethylene glycol 3350 (Miralax’s active ingredient), comes in various quantity packs with approximate costs ranging from $10-$20 depending on size and retailer.

However, there isn't currently an FDA-approved generic version equivalent to Suprep available due to patent protection.

Popularity of Suprep and Miralax

Suprep, the brand name for a combination of sodium sulfate, potassium sulfate, and magnesium sulfate, was prescribed to about 2.1 million people in the U.S. in 2020. Suprep is commonly used as a bowel prep before colonoscopy and accounted for around 11% of all laxative prescriptions within that year.

Polyethylene Glycol 3350 (PEG 3350), sold under the brand name Miralax among others, was prescribed to approximately 3.5 million individuals in the USA during the same period. Miralax accounts for just over 25% of laxative prescriptions annually across America due to its effectiveness as a treatment for occasional constipation or irregular bowel movements.

While both medications work effectively at clearing out your bowels prior to medical procedures like colonoscopies or treating constipation issues, their specific usage can differ depending on patient needs and physician recommendations; it's also worth noting that while both are popularly prescribed treatments in this category of drugs, they operate by distinct mechanisms with different side effect profiles.


Both Suprep (sodium sulfate, potassium sulfate, and magnesium sulfate) and Miralax (polyethylene glycol 3350) are common medications used to alleviate constipation and prepare the bowel for diagnostic procedures such as colonoscopies. They are both osmotic laxatives, meaning they work by increasing fluid in the large intestine which helps soften stools and increase bowel movements.

Suprep is a prescription medication often used specifically for colonoscopy preparation due to its powerful cleansing effect. It's typically taken in two doses: one on the evening before the procedure and another on the morning of.

Miralax, on the other hand, can be purchased over-the-counter without a prescription. It’s generally recommended for occasional relief from constipation rather than intensive bowel cleaning required prior to medical examinations.

The generic form of Miralax may provide significant cost savings compared to brand-name Suprep particularly if you're paying out-of-pocket.

Both drugs have similar side effects including bloating, stomach pain or cramps, nausea or vomiting; however some people find that Suprep has a more unpleasant taste than Miralax.

It’s important when starting treatment with either medication to follow your doctor's instructions carefully regarding dosage and timing especially in preparation for any medical procedures.