From the Guidelines
Polyethylene glycol (PEG) for constipation is typically taken orally as a powder that you mix with water or another beverage, with a standard adult dose of 17 grams daily, as recommended by the American Gastroenterological Association and supported by recent evidence 1. The standard adult dose is 17 grams (about 1 heaping tablespoon) of powder dissolved in 4-8 ounces of water, juice, or other liquid, taken once daily.
- Common brand names include MiraLAX, GlycoLax, and ClearLax.
- For best results, drink the solution completely, preferably in the morning.
- It usually works within 24-72 hours by drawing water into the intestines, softening the stool and making it easier to pass.
- PEG is considered an osmotic laxative and is generally well-tolerated because it doesn't get absorbed into the bloodstream.
- Unlike stimulant laxatives, PEG doesn't typically cause cramping and can be used for longer periods if needed, though you should consult a healthcare provider for constipation lasting more than two weeks, as supported by a recent study published in Gastroenterology 1.
- Make sure to stay well-hydrated while taking PEG, as adequate fluid intake helps the medication work effectively and prevents dehydration.
- The side effects of PEG are generally mild and may include bloating, flatulence, and diarrhea, but these effects are consistent with and expected from laxative therapy, as noted in the study by Chang et al. 1.
From the FDA Drug Label
USE • relieves occasional constipation (irregularity) • generally produces a bowel movement in 1 to 3 days ACTIVE INGREDIENT (IN EACH DOSE) (Bottle Only) Polyethylene Glycol 3350,17 g (cap filled to line) (Packet Only) Polyethylene Glycol 3350,17 g Polyethylene glycol is taken orally for constipation. The typical dose is 17 g of Polyethylene Glycol 3350, which can be taken as a packet or from a bottle filled to the line [ 2(reference_id: 2) ] [ 2(reference_id: 2) ].
From the Research
Dosage and Administration
- Polyethylene glycol (PEG) 3350 is taken at a daily dose of 17g for the treatment of constipation, as established by multiple controlled clinical trials 3.
- A study found that a 68-g dose of PEG laxative seems to provide safe and effective relief in constipated adults within a 24-h period 4.
- For children, the mean effective dose of PEG 3350 was found to be 0.84 g/kg/d, with a range of 0.27-1.42 g/kg/d 5.
Efficacy and Safety
- PEG 3350 has been shown to be effective in improving stool frequency and consistency in patients with constipation, with a significant increase in weekly stool frequency and a reduction in hard/lumpy stools 6.
- The treatment has been found to be safe and well-tolerated, with no significant adverse effects reported in various studies 4, 5, 7.
- A post hoc analysis of a multicenter trial found that once-daily PEG 3350 demonstrated substantial and sustained efficacy and safety over 24 weeks in patients with chronic idiopathic constipation 6.