Does ferrous fumarate have side effects
Emma Miller
Updated on April 11, 2026
Ferrous fumarate works best when taken on an empty stomach. Most people feel better after taking ferrous fumarate for 1 week, but it may take up to 4 weeks to take full effect. Common side effects include feeling or being sick, and diarrhoea. Ferrous fumarate may also be called by the brand names Fersamal and Galfer.
What is the most common adverse effect of ferrous fumarate administration?
Ferrous fumarate tablets can be used during breast-feeding if clinically indicated. Gastrointestinal disorders: The commonest side effects relate to gastrointestinal irritation (nausea, epigastric pain, constipation or diarrhoea).
Is ferrous fumarate well tolerated?
The ferrous product was significantly more effective, the primary and secondary endpoints including changes in levels of hemoglobin and serum ferritin. There was a slightly higher frequency of gastrointestinal side effects in patients taking the ferrous product, but both supplements were well tolerated.
What are the side effects of taking iron pills?
- Constipation.
- Dark stools.
- Stomach upset (pain, bloating, diarrhea, nausea and vomiting)
- Stained teeth.
- Metallic taste.
- Heartburn (irritation of the esophagus lining)
Can iron tablets make you feel worse?
Most Iron Supplements Cause GI Side Effects Those formulations are not easy to tolerate, they are hard on the system and practically make you feel worse than your Iron Deficiency Anemia does. The GI side effects and stomach discomfort can be unbearable.
What happens if you take too much ferrous fumarate?
An overdose of ferrous fumarate can be fatal to a child younger than 6 years old. Overdose symptoms may include stomach pain, nausea, vomiting, diarrhea, cold or clammy skin, blue lips, and loss of consciousness.
How long before ferrous fumarate takes effect?
Taking ferrous fumarate will increase the iron levels in your blood and improve or prevent the symptoms of iron deficiency anaemia. How long does ferrous fumarate take to work? Most people begin to feel better after around 1 week, but it may take up to 4 weeks for the medicine to have full effect.
Can iron pills make you sick?
Iron is best absorbed on an empty stomach. Yet, iron supplements can cause stomach cramps, nausea, and diarrhea in some people. You may need to take iron with a small amount of food to avoid this problem.Is it okay to take iron everyday?
Unlike some supplements, when the subject is iron, more is definitely not better. Adults shouldn’t take any more than 45 mg of iron a day unless they are being treated with iron under close medical supervision.
When should I take iron morning or night?Conclusion. As a rule, people that take an iron supplement should take it in the morning, on an empty stomach, with water or a drink containing vitamin C. And for those who have a sensitive stomach, their best bet is to take their iron right after a meal.
Article first time published onWhich iron supplement has least side effects?
As one of the most reputable supplement brands, Thorne Iron Bisglycinate was sure to be found on this list. This supplement packs 25 mg of iron bisglycinate per capsule, another form of iron claimed to have increased bioavailability and efficacy, as well as fewer gastrointestinal side effects (5, 6 ).
Which is better ferrous sulphate or ferrous fumarate?
Background/objectives: Ferrous fumarate is recommended for the fortification of complementary foods based on similar iron absorption to ferrous sulfate in adults. Two recent studies in young children have reported that it is only 30% as well absorbed as ferrous sulfate.
Is ferrous fumarate better tolerated than ferrous sulfate?
Ferrous salt preparations (ferrous sulfate, ferrous gluconate, and ferrous fumarate) are equally tolerable. (Grade of recommendation: A, based on randomized controlled trial.)
Why do I feel weird after taking iron?
Iron supplements can cause side effects like dizziness, fainting, and hives. Too many iron supplements can cause long-term side effects like liver damage and heart disease. If you want to take iron supplements, talk to your doctor about finding the proper dosage for you.
What do eyes look like when anemic?
Paleness is more commonly seen in moderate or severe cases of anemia (7). If you pull your lower eyelid down, the inside layer should be a vibrant red color. If it is a very pale pink or yellow color, this may indicate that you have iron deficiency.
How much iron is in ferrous fumarate?
For example, ferrous fumarate is 33% elemental iron by weight, whereas ferrous sulfate is 20% and ferrous gluconate is 12% elemental iron [27].
Do iron tablets make you gain weight?
A significant rate of the patients that discontinuing the treatment complained of weight gain during treatment in our clinical practise, despite, oral iron preparations are not known to have such a side effect in adults.
What are the contraindications of ferrous fumarate?
- iron metabolism disorder causing increased iron storage.
- an overload of iron in the blood.
- a type of blood disorder where the red blood cells burst called hemolytic anemia.
- an ulcer from too much stomach acid.
- a type of stomach irritation called gastritis.
Do iron pills make you sleepy?
Side Effects to watch for dark colored stools (this may be due to the iron, but can indicate a more serious condition) drowsiness. pain with or difficulty swallowing.
Can you be allergic to ferrous fumarate?
A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.
What is difference between ferrous ascorbate and ferrous fumarate?
Ferrous Ascorbate vs Ferrous Fumarate: Ferrous Ascorbate + Folic Acid is a combination of two dietary supplements that replenish the body’s reserves of essential nutrients: Ferrous Ascorbate and Folic Acid. Ferrous fumarate is a drug that is used for iron deficiency anaemia treatment and prevention.
Can ferrous fumarate cause headaches?
You also may feel grumpy, have headaches, and have trouble concentrating. Most people begin to feel normal after a few weeks of taking iron pills. But you need to take the pills for several months to build up the iron supply in your body. This can take up to 6 months.
What fruits contain iron?
Fruits like apples, banana and pomegranates are a rich source of iron and must be taken each day by anaemic individuals to get those pink cheeks and stay in pink of health. Mulberries and black currants too are iron-rich. The dark pink juice that oozes out of beetroot aptly represents its potency to cure anaemia.
Should I take a multivitamin with iron?
Do not crush, chew, break, or open an extended-release capsule or tablet. Swallow it whole. It is important to take multivitamins with iron regularly to get the most benefit.
Are eggs high in iron?
Eggs, Red Meat, Liver, and Giblets Are Top Sources of Heme Iron.
What are the signs of too much iron?
- tiredness or fatigue.
- weakness.
- weight loss.
- abdominal pain.
- high blood sugar levels.
- hyperpigmentation, or the skin turning a bronze color.
- a loss of libido, or sex drive.
- in males, reduction in the size of the testicles.
What is the best tolerated iron supplement?
Conclusion: Extended-release ferrous sulfate with mucoproteose appears to be the best tolerated of the different oral iron supplements evaluated.
Does ferrous sulfate increase BP?
The subjects took ferrous sulfate for 2 weeks. There was an increase in both systolic and diastolic blood pressure in four patients and a decrease in blood pressure in all patients after ferrous sulfate was discontinued. The increases in blood pressure were substantial in three of the patients.
Can I take iron at bedtime?
Take your supplement before bed. This is likely to be the easiest time to have an empty stomach. Cutting off your food intake two hours before bed will also have other benefits.
Is it OK to take iron at bedtime?
Iron. Majumdar says that iron is best absorbed on an empty stomach, but can be difficult to tolerate, causing upset stomach, nausea and constipation. “Consider first trying it on an empty stomach, and if not tolerated, take at night before bed,” she suggests.
How do you know if iron tablets are working?
An iron supplement that is working well should be easy to take with no side effects, and you should have a noticeable increase in your energy levels. When choosing an iron supplement, it is essential to choose one strong on absorption whilst gentle on the stomach.