Experiences with
Ferrous fumarate

Ferrous fumarate is a type of iron that's used as a medicine to treat and prevent iron deficiency anaemia.

Iron helps the body to make healthy red blood cells which carry oxygen around the body. Some things such as blood loss, pregnancy or too little iron in your diet can make your iron supply drop too low, leading to anaemia.

Ferrous fumarate comes as tablets, capsules or as a liquid that you swallow.

It's available on prescription and to buy from pharmacies.

Who can take ferrous fumarate

Most adults can take ferrous fumarate with the advice of a doctor or pharmacist.

Children can take it if a doctor has recommended it.

Who may not be able to take ferrous fumarate

Ferrous fumarate may not be suitable for some people.

To make sure it's safe for you, tell your doctor or pharmacist before starting to take it if you:

have ever had an allergic reaction to ferrous fumarate or any other medicine
have a different type of anaemia that is not caused by low levels of iron
have any other conditions that affect your iron levels, such as haemochromatosis or haemosiderosis
have a condition that affects your red blood cells, such as sickle cell anaemia or thalassaemia
have a stomach ulcer, or other stomach or bowel problems such as inflammatory bowel disease (IBD)
are having repeated blood transfusions
have noticed blood in your pee

Dosage and strength

Ferrous fumarate tablets come in 2 strengths: 210mg and 322mg.

Ferrous fumarate capsules are 305mg.

Liquid ferrous fumarate contains 140mg in each 5ml spoonful (140mg/5ml).

Your dose depends on why you're taking it and whether you take tablets, capsules or liquid.

Dose to treat anaemia

The usual dose of ferrous fumarate for adults and children aged 12 years and over is:

210mg tablets – 1 tablet, taken 1 to 3 times a day
322mg tablets – 1 tablet, taken 1 or 2 times a day
305mg capsules – 1 capsule, taken 1 or 2 times a day
liquid (140mg/5ml) – one or two 5ml spoonfuls, taken 1 or 2 times a day

If you get side effects your doctor may advise you to reduce your dose by taking it on alternate days.

For children under 12 years, a doctor will use your child's age or weight to work out the right dose.

Dose to prevent anaemia

The usual dose of ferrous fumarate for adults and children aged 12 years and over is:

210mg tablets – 1 tablet, taken 1 or 2 times a day
322mg tablets – 1 tablet, taken once a day
305mg capsules – 1 capsule, taken once a day
liquid (140mg/5ml) – one 5ml spoonful, taken 1 or 2 times a day, or two 5ml spoonfuls taken once a day

If you get side effects your doctor may advise you to reduce your dose by taking it on alternate days.

For children under 12 years, the doctor will use your child's age or weight to work out the right dose.

How to take it

Ferrous fumarate works best when you take it on an empty stomach. If you can, take it at least an hour before eating, and 2 hours after eating. But if it upsets your stomach, you can take it with or just after food.

Your doctor (or a pharmacist) may recommend taking ferrous fumarate with orange juice or a vitamin C supplement. Vitamin C is believed to increase the amount of iron absorbed by the body.

Swallow tablets or capsules with a drink of water or juice only. Do not take them with milk, as milk stops the iron getting into your system.

The liquid may be easier for children and people who find it difficult to swallow tablets or capsules.

If you're taking ferrous fumarate as a liquid, it will come with a plastic syringe or spoon to help you measure the right dose. If you do not have one, ask your pharmacist for one. Do not use a kitchen teaspoon as it will not measure the right amount.

Keep ferrous fumarate out of sight and reach of children, as an overdose may be fatal.

Ferrous fumarate is not harmful if it has been prescribed for your child and you follow your doctor's instructions, or the instructions on the packet.

How long to take it for

To prevent iron deficiency anaemia, you'll need to take ferrous fumarate for as long as you're at risk of getting this condition.

To treat iron deficiency anaemia, you'll need to take it for several months. Your doctor will usually advise you to keep taking it for 3 to 6 months after your condition has improved to help build up your body's iron supply.

If you forget to take it

If you forget a dose of ferrous fumarate and you usually take it:

once a day – take it as soon as you remember, unless it's less than 12 hours until your next dose. In this case, skip the missed dose and take your next dose at the usual time
2 times a day – if you remember within 4 hours of your missed dose, take it as soon as you remember. If you remember more than 4 hours after your missed dose, skip the missed dose and then take your next one at the usual time
3 times a day – skip the missed dose and take your next dose at the usual time

Do not take 2 doses to make up for a forgotten dose.

If 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.

If you take too much

Taking more than the recommended dose of ferrous fumarate can cause vomiting, stomach pain or diarrhoea.

In serious cases you may vomit blood, bleed from your bottom, have a seizure or fit, or become unconscious.

you or your child takes more than the recommended dose of ferrous fumarate

Go to 111.nhs.uk or call 111

If you need to go to A&E, do not drive. Ask someone to drive you or call 999 and ask for an ambulance.

Bring the ferrous fumarate packet or leaflet inside it, any remaining medicine, and any other medicines you take.

Common side effects

There are things you can do to cope with these common side effects of ferrous fumarate:

Try taking ferrous fumarate with, or just after, a meal or snack. Stick to simple meals and do not eat rich or spicy food. If you're being sick, try small frequent sips of water to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee.

If you take the combined contraceptive pill or the progestogen-only pill and you're being sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.

Eat when you would usually expect to be hungry. If it helps, eat smaller meals more often than usual. Snack when you're hungry. Have nutritious snacks that are high in calories and protein, such as dried fruit and nuts.

Get more fibre into your diet by eating fresh fruit, vegetables and cereals, and drink plenty of water. Try to exercise more regularly, for example, by going for a daily walk or run. If this does not help, talk to a pharmacist or doctor.

Drink lots of fluids, such as water or squash, to avoid dehydration. Signs of dehydration include peeing less than usual or having dark, strong-smelling pee. Do not take any other medicines to treat diarrhoea without speaking to a pharmacist or doctor.

If you take the combined contraceptive pill or the progestogen-only pill and you have severe diarrhoea for more than 24 hours, your contraception may not protect you from pregnancy. Check the pill packet for advice.

This is common when taking iron and is usually nothing to worry about.

Rinse your mouth with water after taking the medicine.

Speak to a doctor or pharmacist if the advice on how to cope does not help and a side effect is still bothering you or does not go away.

Serious side effects

Talk to a doctor or call 111 straight away if your poo is black, tar-like or red, or has blood in or on it, or if you also feel unwell in any other way.

Serious allergic reaction

In rare cases it's possible to have a serious allergic reaction (anaphylaxis) to ferrous fumarate.

Meds New IA (H4) - serious allergic reaction

These are not all the side effects of ferrous fumarate.

For a full list, see the leaflet inside your medicine packet.

Ferrous fumarate and pregnancy

Your doctor or midwife may recommend that you take an iron supplement (ferrous fumarate) in pregnancy. Iron supplements are safe to take in pregnancy and it is important that low iron levels are treated so that you and your baby stay healthy.

If you are pregnant and taking iron supplements, it is common to become constipated or get piles (haemorrhoids). A doctor, pharmacist or midwife can give you advice on how to avoid this. If you do get constipation or piles, talk to a doctor, midwife or pharmacist about the best way to treat this.

Ferrous fumarate and breastfeeding

You can usually take ferrous fumarate while you are breastfeeding.

Iron (including ferrous fumarate) is a natural part of breast milk. When you take iron as a supplement it does not affect how much gets into breast milk or how much gets to your baby.

This means that taking iron supplements is very unlikely to cause any side effects in your baby.

However, if your baby also has low iron levels, they will need to be treated directly. Any iron supplements that you are taking will not affect their levels.

If you notice your baby is not feeding as well as usual, or has constipation or diarrhoea, or you have any other concerns about your baby, contact your doctor, pharmacist, health visitor or midwife.