Macrogol draws water into the bowel and holds it there, softening hard stool so it can pass. It is the laxative most often reached for when stools are hard rather than simply infrequent, and it is the standard choice for constipation caused by codeine or morphine, where bulk-forming laxatives do not work.
Short-term and long-term constipation in adults and children, faecal impaction (using a higher dose over a few days under advice), and constipation caused by opioid painkillers.
It is generally preferred over stimulant laxatives for regular use, because it works with the body rather than forcing the bowel.
Each sachet is dissolved in the stated volume of water — usually 125ml for a standard sachet. Using less water than stated makes it less effective, because the water is part of how it works.
Stir until fully dissolved and drink. Once made up it can be kept covered in the fridge for up to 24 hours.
The usual adult dose for ordinary constipation is one to three sachets a day, adjusted to effect. It typically takes one to three days to work — it is not an overnight remedy, so give it time before increasing the dose.
Children’s doses are worked out by age and situation, and higher “disimpaction” regimes should only be used on advice.
Bloating, wind, mild stomach ache and nausea are the common ones, and often settle as your bowel adjusts. Diarrhoea usually means the dose is too high — reduce it rather than stopping altogether.
Get medical advice for severe abdominal pain, vomiting, or if you stop passing wind as well as stool.
Macrogol is generally suitable in pregnancy and while breastfeeding, and can be used long term where needed — it is not habit-forming in the way people fear with stimulant laxatives.
Leave an hour or so between macrogol and other medicines where possible, since it can speed things through the gut.
Keep fluid intake up generally. Fibre and activity still matter alongside it.
1 Lyng Lane, West Bromwich B70 7RW · Mon–Fri 8:30am–6pm, Sat 9am–1pm · 0121 500 5756
Ask our pharmacist →We use essential cookies to make the site work — things like your basket, sign-in and secure checkout. With your permission we’d also like to use analytics cookies to understand how the site is used and improve it. See our cookie policy.
