Macrogol (or macrogols) is a laxative taken to treat constipation (difficulty pooing). It's also taken to help clear a build-up of hard poo in your bowel, which can happen if you've been constipated for a long time (faecal impaction).
It can also be given before a colonoscopy (a test to check inside your bowels) to empty your bowels before the test. Find out about getting ready for a colonoscopy.
Macrogol comes as sachets of powder that you mix with water to make a drink, a ready-mixed solution to drink, or a liquid that you need to dilute before drinking.
It's available on prescription and to buy from pharmacies.
Macrogol is also called by the brand names Movicol, Laxido, CosmoCol, Molaxole or Molative.
Paediatric powder sachets will be prescribed for children under 12 years of age, these brands include CosmoCol Paediatric and Movicol Paediatric.
Macrogol can be taken by most adults including pregnant and breastfeeding women. You can buy laxatives with macrogol in for children over 12 years of age. However, babies and children under 12 years old can only take macrogol with a prescription from a doctor.
Macrogol is not suitable for some people. To make sure it's safe for you, tell a doctor or pharmacist if you:
Most types of macrogol contain a lot of sodium (sodium is also found in table and cooking salt). Each dose can contain around 10% of your recommended daily amount of sodium.
Do not give macrogol to a child under 12 years old unless a doctor has prescribed it.
You can take macrogol with or without food.
The amount you take depends on how bad your constipation is. Ask a pharmacist for advice if you're not sure.
The usual dose for constipation for adults and children over 12 years old:
Paediatric powder sachets will be prescribed to children under 12 years old.
The usual dose of paediatric sachets for constipation for children aged:
Children under 12 do not need take all of the drink at one time. They can take half in the morning and half in the evening.
A doctor will tell you if you have faecal impaction and they will advise you on how much to take.
The usual dose for faecal impaction for adults and children over 12 years old:
The usual dose of paediatric sachets for faecal impaction for children aged:
Only give macrogol to children under 12 years old if a doctor has prescribed it.
How you take macrogol depends on what type you are taking. If you're not sure which macrogol you have and how to take it, read the information in the packet or speak to a pharmacist.
Ready-to-drink sachets
Drink the contents straight from the packet.
Powder sachets
Dissolve each sachet in 125ml (1/4 pint) of water and stir well, then drink. These are usually flavoured, but if you or your children do not like the flavour, you can add fruit squash to the drink and the medicine will still work properly.
Never swallow the powder without water. If you have severe faecal impaction, it's important to drink extra fluids (water if possible) every day as well as your usual amount.
It's also important with faecal impaction for you (or a child over 12 years old) to drink the daily dose within a 6-hour period. If your child is under 12 years of age, make sure they drink the full daily dose within 12 hours.
Liquid (in a bottle)
You need to dilute the liquid before drinking it.
Open the bottle and measure 25ml (or five 5ml spoonfuls). If you do not have a 5ml medicine spoon ask a pharmacist for one, do not use a kitchen teaspoon as it will not give the right amount.
Pour this into half a glass of water (100ml). Stir well until all the liquid has been evenly mixed and it looks clear, then drink it.
Make sure you or your child finish the whole drink. You can drink it in one go or sip it over 30 minutes. It might help to use a straw. You can make the mixture in advance if you need to take it to work or school.
If you forget a dose of macrogol, do not worry, just take the next dose at the usual time.
Never take 2 doses at the same time. Never take an extra dose to make up for a forgotten one.
If a doctor has told you to take macrogol every day and you often forget doses, it may help to set an alarm to remind you. You could also ask a pharmacist for advice on other ways to help you remember to take your medicine.
Taking an extra dose of macrogol by accident is unlikely to harm you. You may get diarrhoea and stomach pain but this should ease within a day or two. If it does not, stop taking macrogol and wait for the diarrhoea and stomach pain to pass.
If you're worried, talk to a doctor or pharmacist for advice.
Like all medicines, macrogol may cause side effects in some people, but many people have no side effects or only minor ones.
Common side effects, which happen in more than 1 in 100 people, are:
These side effects usually get better if you reduce the amount of macrogol or after you have had a poo. Talk to a doctor or pharmacist if the side effects bother you or do not go away.
Call a doctor straight away if these rare but serious side effects happen to you:
These side effects might mean that there have been changes in the electrolytes in your blood. A doctor can check this with an electrolyte test.
In rare cases, it's possible to have a serious allergic reaction (anaphylaxis) to macrogol.
You could be having a serious allergic reaction and may need immediate treatment in hospital.
These are not all the side effects of macrogol. For a full list see the leaflet inside your medicines packet.
You can report any suspected side effect to the UK safety scheme.
Macrogol is generally safe to take during pregnancy and while breastfeeding. Constipation is common at the end of pregnancy and just after having a baby.
If you're pregnant or breastfeeding, it's always better to try to safely treat constipation without taking a medicine.
A doctor or midwife will first advise you to eat more fibre (like potatoes, high-fibre cereals, wholemeal bread, brown rice or wholewheat pasta, fruit and vegetables) and drink plenty of fluids. You'll also be encouraged to do gentle exercise.
If dietary and lifestyle changes do not work, you may be recommended a laxative such as macrogol.
For more information about how laxatives can affect you and your baby during pregnancy, read this leaflet on the Best Use of Medicines in Pregnancy (BUMPS) website.
Tell a pharmacist or doctor if you're trying to get pregnant, are already pregnant or if you're breastfeeding.
Some medicines, such as epilepsy medicines like phenytoin, may not work as effectively if you use macrogol at the same time.
There are no known problems mixing macrogol with herbal remedies or supplements.
For safety, tell a doctor or pharmacist if you're taking any other medicines, including herbal remedies, vitamins or supplements.
Macrogol is known as an "osmotic" laxative. This means it draws water from the rest of the body into your bowel to make your poo slightly bigger and softer.
It then triggers your bowels to start working to push the poo out.
Macrogol can take 1 to 2 days to start working.
Talk to a doctor if you are still constipated after 3 days.
You can eat and drink normally while taking macrogol.
It might be a good idea to stop eating pastries, puddings, sweets, cheese and cake for a while as these foods can make constipation worse.
Yes, you can drink alcohol with macrogol.
It's often possible to improve constipation without laxatives. Before trying macrogol or to stop constipation coming back it may help to:
You can take macrogol for as long as the constipation lasts, or for as long as the doctor has recommended. This will usually be for up to 2 weeks.
The doctor may recommend that you take it for many months if you or your child has serious constipation or take medicines that cause constipation.
Usually for long-term treatment, the dose can be lowered to either 1 or 2 sachets a day.
For faecal impaction, you'll usually only need to take macrogol for up to 3 days, but you may be given a lower dose to take for a little longer.
Ideally, you should only take macrogol occasionally and for a few days at a time.
Using laxatives like macrogol for longer can lead to prolonged diarrhoea. It can also cause an electrolyte imbalance, where levels of substances like sodium, potassium and magnesium in your body get too high or too low.
In some people, an electrolyte imbalance can cause serious health problems such as muscle spasms, twitching and fits (seizures).
However, sometimes a doctor may recommend you or your child take macrogol for a few months. This could be because you keep getting constipation or you take medicines that make you constipated. If this happens, the doctor will decide how long and how much macrogol you need to take.
Usually, it's best to only take macrogol when you have constipation. You can stop taking it for short-term constipation if you are going to the toilet as normal.
If you stop taking it, your constipation might come back.
There are other types of laxatives. Some work in a different way to macrogol but are equally good at treating constipation. Some work more quickly than macrogol.
For most people, 1 laxative will be enough to relieve constipation.
Occasionally, you may need to take 2 different types of laxatives at the same time.
Only take 2 laxatives together if a doctor recommends it as there's more risk of getting side effects.
Macrogol does not affect any type of contraception including the combined pill or emergency contraception unless you have severe diarrhoea for more than 24 hours.
If you have severe diarrhoea your contraceptive pills may not protect you from pregnancy. Look on the pill packet to find out what to do.
Read more about what to do if you're on the pill and you're being sick or have diarrhoea.
There's no firm evidence to suggest that taking macrogol will reduce fertility in either men or women.
Yes, macrogol has no effect on driving, riding a bike or using machinery.