Ferrous fumarate is a medicine used to treat and prevent iron deficiency anaemia.
It comes as capsules or as a liquid that you swallow.
You can get it on prescription and and you can buy it over the counter from pharmacies.
Ferrous fumarate may also be known by the brand name Galfer.
When you start taking ferrous femarate
You might feel better after taking ferrous fumarate for a week, but it may take up to 4 weeks to take full effect. If you still feel unwell after 4 weeks, talk to your GP or pharmacist.
You probably will not feel any different if you’re taking ferrous fumarate to prevent anaemia, but that does not mean it is not working.
You may experience these common side effects:
- feeling or being sick
- diarrhoea
- constipation
- a change in colour of your poo
Check if you can take ferrous fumarate
You can usually take ferrous fumarate if you’re age 18 and over.
Important
Keep ferrous fumarate out of the reach of children. An overdose of iron can be fatal.
Ferrous fumarate is not harmful if it’s been prescribed for your child. Follow your GP’s instructions, or the instructions on the packet.
If you buy this medicine from a pharmacy, tell the pharmacist before starting ferrous fumarate if you:
- have 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 haemosiderosis or haemochromatosis
- 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
- are having repeated blood transfusions
- see blood in your pee
Non-urgent advice: Tell your GP if you're:
- trying to get pregnant
- pregnant
- breastfeeding
Pregnancy and ferrous fumarate
Your doctor or midwife may recommend that you take ferrous fumarate in pregnancy.
Iron supplements such as ferrous fumarate are safe to take in pregnancy. It is important that low iron levels are treated so that you and your baby stay healthy.
It’s common to become constipated or develop piles (haemorrhoids) if you’re pregnant and taking iron supplements. If this happens to you, talk to your GP.
Breastfeeding and ferrous fumarate
Talk to your GP if you are breastfeeding and taking ferrous fumarate. Small amounts of the medicine may pass into your breast milk. But it’s unlikely to harm your baby.
Fertility and ferrous fumarate
There's no evidence that ferrous fumarate reduces fertility in either men or women.
How and when to take it
Follow your GP’s instructions about how and when to take ferrous fumarate. They will tell you what dosage is right for you.
Follow the instructions that come with the packet.
Your GP or pharmacist may recommend taking ferrous fumarate with orange juice or a vitamin C supplement. This is to help your body to absorb the iron.
Do not use a kitchen teaspoon to measure the liquid because you will not get the right amount. The medicine will come with a plastic syringe or spoon to help you measure the right dose. If you do not have a plastic syringe or spoon, ask your pharmacist for one.
Eating and drinking
Take ferrous fumarate either:
- 30 minutes before eating, or
- 2 hours after eating
If it upsets your stomach, you can take it with or just after food.
After taking ferrous fumarate wait 2 hours before eating or drinking any of the following:
- tea and coffee
- milk and dairy products - such as yoghurt and cheese
- eggs
- soybean products - such as soya beans and soya milk
This will help your body take in the iron.
You can drink alcohol while you are taking ferrous fumarate.
If you forget to take it
Do not take a double dose to make up for a forgotten dose.
Once a day
If you take ferrous fumarate once a day, take the missed dose as soon as you remember. Do this unless it's less than 12 hours until your next dose. If it is, skip the missed dose.
Twice a day
If you take ferous fumarate twice 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 dose as normal
Three times a day
If you take ferous fumarate three times a day, skip the missed dose and take your next dose as normal.
If you take too much
Taking too much 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.
Emergency action required: Call 112 or 999 or go to an emergency department (ED) immediately if you or your child:
- takes too much ferrous fumarate
If you go to an ED do not drive yourself. Get someone else to drive you, or call an ambulance.
Take the ferrous fumarate packet or the leaflet inside it with you, and any remaining medicine.
Side effects
Many people have no side effects or only minor ones.
There are things you can do to cope with the common side effects of ferrous fumarate:
Feeling sick or getting sick (nausea or vomiting)
Try taking ferrous fumarate with food if you feel sick (nausea) or are getting sick (vomiting).
Stick to simple meals and do not eat rich or spicy food. If you're getting 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 getting sick, your contraception may not protect you from pregnancy. Check the pill packet for advice.
Stomach discomfort or heartburn
Try taking ferrous fumarate with food. It can help to eat and drink slowly and have smaller and more frequent meals. If this does not help, ask a pharmacist or GP for advice.
Losing your appetite
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.
Constipation
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 GP.
Diarrhoea
Drink lots of fluids, such as water, 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 GP.
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.
Darker than usual poo
This is common when taking iron and is usually nothing to worry about.
Talk to your GP, a pharmacist or nurse if the advice on how to cope does not work or a side effect bothers you or does not go away.
Serious allergic reaction
A serious allergic reaction to ferrous fumarate is rare. But you will need to go to an emergency department (ED) if you have symptoms.
Emergency action required: Call 112 or 999 or go to an ED immediately if:
- you get a skin rash that may include itchy, red, swollen, blistered or peeling skin
- you're wheezing
- you get tightness in your chest or throat
- you have trouble breathing or talking
- your mouth, face, lips, tongue or throat start swelling
These are warning signs of a serious allergic reaction (anaphylaxis).
See the patient information leaflet that comes with your medicine for a full list of side effects.
Non-urgent advice: Find your patient information leaflet
Your patient information leaflet is the leaflet that comes with your medicine. You can find a digital version of the leaflet online.
Report side effects
You can report any suspected side effects to the Health Products Regulatory Authority (HPRA): report an issue - hpra.ie
Taking ferrous fumarate with other medicines
Some medicines interfere with the way ferrous fumarate works
Non-urgent advice: Check with your GP, pharmacist or nurse if:
- you’re on any other medicines or supplements
Do this before you start taking ferrous fumarate.
Try to leave a gap between taking other medicines and ferrous fumarate. Ask your GP, a pharmacist or nurse for advice on how long the gap should be.
Mixing ferrous fumarate with herbal remedies or supplements
Talk to a pharmacist or GP before taking any herbal remedies or supplements together with ferrous fumarate. Some vitamin and mineral supplements may already contain ferrous fumarate.
Tell a pharmacist or GP if you take any supplements or remedies that contain:
- iron
- calcium
- magnesium
- zinc
Ferrous fumarate can stop zinc working as well as it should. Calcium can reduce the effect of ferrous fumarate.
Fact check
This content was fact checked by a pharmacist, a GP, and the National Medication Safety Programme (Safermeds).
