From the Guidelines
For adult constipation, the standard MiraLAX (polyethylene glycol 3350) dose is 17 grams (about 1 heaping tablespoon or one capful of the powder) dissolved in 8 ounces of water, juice, or another beverage once daily, as recommended by the most recent and highest quality study 1. This dose is supported by the American Gastroenterological Association-American College of Gastroenterology clinical practice guideline, which states that PEG is approved at a dose of 17 g daily for the treatment of occasional constipation by the FDA in the United States and is widely available OTC 1. The medication works by drawing water into the colon, softening the stool and making it easier to pass. Some key points to consider when taking MiraLAX include:
- Take the dose at the same time each day for best results
- MiraLAX typically produces a bowel movement within 1-3 days
- Drink plenty of fluids throughout the day while taking MiraLAX to prevent dehydration and help the medication work effectively
- If symptoms persist beyond 7 days, consult a healthcare provider
- If you experience severe abdominal pain, nausea, vomiting, or signs of an allergic reaction, discontinue use and seek medical attention. It's also worth noting that PEG has been shown to be efficacious in individuals with chronic idiopathic constipation for up to 6 months, and has a similar or greater efficacy compared to other medications such as tegaserod, prucalopride, and lactulose 1. Additionally, PEG is considered a safe and tolerable option for elderly patients, with a good safety profile 1.
From the FDA Drug Label
ACTIVE INGREDIENT (IN EACH DOSE) (Bottle Only) Polyethylene Glycol 3350,17 g (cap filled to line) (Packet Only) Polyethylene Glycol 3350,17 g The recommended dose of Miralax for adult constipation is 17 g of Polyethylene Glycol 3350 per dose 2.
- The dose can be taken as a 17 g packet or by filling the bottle cap to the line, which also contains 17 g of Polyethylene Glycol 3350.
From the Research
Miralax Dose for Adult Constipation
- The recommended dose of Miralax (polyethylene glycol 3350) for adult constipation is not explicitly stated in the provided studies.
- However, according to the studies, polyethylene glycol-based preparations are supported by good evidence as a first-line laxative for chronic constipation 3, 4.
- A study comparing lactulose and polyethylene glycol for chronic constipation found that polyethylene glycol is better than lactulose in outcomes of stool frequency per week, form of stool, relief of abdominal pain, and the need for additional products 5.
- The American Journal of Gastroenterology study provides evidence-based recommendations for the use of over-the-counter therapies for chronic constipation, including polyethylene glycol, but does not specify a dose 4.
- It is essential to follow the recommended dosage instructions on the label or consult a healthcare professional for personalized guidance on using Miralax for adult constipation.
Key Findings
- Polyethylene glycol-based preparations, such as Miralax, are effective and safe for treating chronic constipation 3, 4.
- The choice of laxative and dosage may depend on individual factors, such as the severity of constipation and personal preferences 4.
- Common adverse effects of laxatives, including polyethylene glycol, are abdominal pain, cramping, bloating, diarrhea, and nausea 3, 4.