An Overview of Injectafer for Treating Iron Deficiency Anemia

Injection/Infusion Therapy

Injectafer (ferric carboxymaltose) is used to treat iron deficiency anemia. This is related to different sources, including poor nutrition, menstrual bleeding, and poor absorption.

It comes as an injection administered by infusion. It is useful for people who cannot take iron by mouth or have experienced side effects or unsuccessful treatment responses from oral forms of iron. It is also prescribed to people who have long-term chronic kidney disease.

Keep reading to learn more about iron deficiency anemia, how Injectafer therapy works, and the side effects and adverse effects associated with Injectafer.

Man receiving infusion from nurse.

Space_Cat / Getty Images

What Is Iron Deficiency Anemia?

Iron deficiency anemia is a common type of anemia where the blood lacks adequate healthy red blood cells. Your body needs red blood cells to carry oxygen to all the body’s tissues.

As its name specifically implies, iron deficiency means the body lacks sufficient iron. Without enough iron, the body cannot produce enough hemoglobin—a substance red blood cells need to carry oxygen. When the body lacks iron and cannot produce enough hemoglobin, iron deficiency can leave a person extremely fatigued and short of breath.

If you report symptoms of iron deficiency anemia, your doctor will request blood tests to determine the source of your symptoms. Your doctor may request additional tests if they suspect another condition is causing your iron deficiency anemia.

Signs and symptoms of iron deficiency anemia might include:

  • Shortness of breath
  • Dizziness
  • Extreme fatigue
  • Frequent infections
  • Pale skin, nail beds, or gums
  • Restless legs
  • Heart palpitations
  • Mouth sores
  • Brittle nails
  • Cravings for non-food items like dirt, ice, or paint
  • Glossitis (swelling of the tongue)

Iron deficiency anemia can be corrected with iron supplementation and diet changes.

How Injectafer Works

Injectafer drug therapy can help increase hemoglobin levels back to the normal range. It contains an active drug called ferric carboxymaltose.

Injectafer is part of a group of drugs known as iron replacement products. Iron infusions can help to increase your iron levels more quickly and offer more immediate treatments than supplements or diet changes. This can be extremely helpful to people with extreme anemia.

Once Injectafer enters the system, it releases iron that is then used to make hemoglobin and red blood cells. The benefits of Injectafer include improved breathing and increased energy. You should start to feel the effects within a few weeks of starting treatment.

How long the benefits continue depends on the source of your anemia and if you use other treatments to increase iron levels. Your doctor might recommend additional iron therapies, including supplements and diet changes, to further enhance Injectafer therapy.

Administration and Dosing

Injectafer is given by injection into a vein—usually by a healthcare professional who has been directed by your prescribing doctor. It is mixed with a saline solution and administered as an infusion into a vein.

It is given in two doses at least seven days apart. When administering the drug, the clinician will send the medication through the vein slowly over several minutes.

In 2021, the drug’s manufacturer announced the Food and Drug Administration’s (FDA) approval of a single dose 1,000 milligram (mg) dose option of Injectafer to treat iron deficiency anemia.

Injectafer was previously approved by the FDA in 2013 as a 1,500 mg treatment administered as two 750 mg doses. The two-dose option is still considered the proven treatment for the full replacement of iron for adults with iron deficiency anemia.

For people weighing less than 110 pounds, the dosage is adjusted by body weight. It is given in two doses, separated by at least seven days. 

The dosage your doctor will prescribe will depend on the medical condition being treated, your weight, and your response to treatment. All strengths can be repeated if iron deficiency anemia reoccurs.

Injectafer has also been used to treat nondialysis-dependent chronic kidney disease. Your doctor might request lab work to monitor your response to the drug.

Before Using

Before starting Injectafer, you should let your doctor know if you are allergic to it or any other iron therapies. Your doctor also needs to know if you have allergies, as Injectafer might contain inactive ingredients, which can cause other reactions and problems.

Your doctor also needs to know about your medical history, especially if you have liver disease or other liver issues. Tell your doctor if you have currently or have had in the past anemia not related to iron deficiency, iron overload, or high blood pressure. Injectafer might make these conditions worse.

Injectafer can cause severe dizziness. Do not drive, use machinery, or do anything that requires you to be alert unless you can do it safely. Limit your use of alcohol. You should also avoid the use of recreational drugs.

Let your doctor know about all the products you use, including prescription and nonprescription drugs, vitamins, and herbal supplements. If you are pregnant, talk to your doctor about the risks and benefits of Injectafer during pregnancy.

Side Effects

Along with its desired effects, Injectafer can have unwanted side effects. You may experience some or many of the possible side effects. Some of these side effects are minor, while others may require medical attention.

Common Side Effects

After you have had an infusion treatment, you can return to your normal activities. Most people can drive home after the treatment. You can even return to work if you feel up to it.

Most common side effects occur right after the treatment, and most are mild. These might include:

  • Changes to your sense of taste
  • Headaches
  • Nausea and vomiting
  • Muscle or joint pain
  • Shortness of breath
  • Rash or itchiness
  • Increased or decreased blood pressure
  • Increased or decreased heart rate
  • Burning or swelling at the infusion site 

Severe Side Effects 

An extremely rare but serious complication that can occur with Injectafer is iron toxicity. Signs of iron toxicity will come on quickly and can lead to anaphylactic shock.

Other signs of toxicity include:

  • Dizziness
  • Low blood pressure
  • Fast or weak pulse
  • Weakness
  • Fever
  • Shortness of breath
  • Fluid in the lungs
  • Bluish or greyish skin color
  • Jaundice (yellowing of skin from liver damage)
  • Seizures

Anaphylactic shock can occur when the immune system responds and releases chemicals that flood the body in response to anaphylaxis, a life-threatening allergic reaction. With anaphylactic shock, blood pressure drops suddenly, and the airways narrow, sometimes blocking normal breathing.

Anaphylactic Shock

Anaphylactic shock is a dangerous condition that can result in other serious and life-threatening conditions, such as brain damage or kidney damage. It needs immediate treatment.

Iron toxicity can also come on slowly and develop over time if there is too much iron in the body’s tissues. Doctors will take caution by using a test dose and a slow infusion to prevent iron toxicity.

Your doctor also uses the test dose to monitor for other reactions. For example, reactions might include anaphylaxis, shock, severe hypotension (low blood pressure), and loss of consciousness.

The information above is not a complete list of side effects. If you notice other effects, reach out to your doctor.

Additional Treatments for Anemia 

In addition to iron infusion therapies, your doctor might recommend iron supplements. In some cases, treatment may also include treating the underlying cause of the iron deficiency. Other treatments include diet changes or a blood transfusion.

Iron Supplements

Your doctor might recommend an over-the-counter (OTC) iron supplement to increase the amount of iron in your body. Your doctor will let you know the right dose for you.

To improve absorption of iron supplements, your doctor might recommend you do the following:

  • Take iron supplements on an empty stomach. But if treatments upset your stomach, you may need to take your iron supplements with food.
  • Don’t take iron supplements with antacids. Antacids can interfere with the absorption of iron. You should wait a few hours after taking an antacid to take your iron supplement.
  • Take iron supplements with vitamin C. Vitamin C can improve iron absorption. Your doctor might recommend drinking a glass of orange juice when you take your supplement or a vitamin C supplement.
  • Iron supplements can lead to constipation, so your doctor might recommend a stool softener. Other side effects like black stools are usually harmless.

You will need to take iron supplements for many months to increase your iron levels. You might start to feel better after a couple of weeks of treating with iron supplements but don’t stop taking the supplements until your doctor has checked your iron levels and confirmed they are within a normal range. 

Treating Underlying Causes             

When iron supplements don’t improve blood iron levels, iron deficiency is likely related to bleeding or an iron absorption problem. Your doctor will work towards investigating the source and treating it.

Depending on the source, your doctor will prescribe appropriate treatments. For example, if heavy menstrual bleeding leads to anemia, medications, such as oral contraceptives, can lessen blood flow.

If the source is a peptic ulcer, antibiotics and other medicines may be prescribed. Your doctor might recommend surgery for other problems, such as a bleeding tumor, polyp, or fibroid.


Changes to your diet can help treat iron deficiency anemia.

Some foods that can help to improve iron levels are: 

  • Red meat
  • Dark green leafy vegetables
  • Dried fruit
  • Nuts
  • Iron-fortified cereal

Blood Transfusion 

In very severe cases of anemia, doctors recommend a blood transfusion. This is the quickest way to replace iron and blood loss.


Injectafer is an intravenous infusion used to treat iron deficiency anemia. It is usually administered in a clinic setting in two sessions at least seven days apart, but a single-dose option has been approved by the FDA. Most side effects are mild. Iron toxicity or anaphylactic shock are seen rarely. Your doctor may recommend other forms of treatment in addition to Injectafer.

A Word From Verywell

Even in the most severe cases, the outlook for iron deficiency anemia is good if a person receives appropriate treatment. Left untreated, iron deficiency anemia can have dangerous complications, including infection, heart problems, and pregnancy complications.

You can reduce your risk for complications by following your doctor’s treatment plan. You should reach out to your doctor right away if you feel you cannot take your treatments due to side effects, costs, or for any other reason.  

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Bregman DB, Goodnough LT. Experience with intravenous ferric carboxymaltose in patients with iron deficiency anemia. Ther Adv Hematol. 2014;5(2):48-60. doi:10.1177/2040620714521127

  2. Food and Drug Administration. Highlights of prescribing information. INJECTAFER® (ferric carboxymaltose injection), for intravenous use.

  3. Daiichi Sankyo, Inc. Injectafer® (ferric carboxymaltose injection) receives FDA approval for single dose option for the treatment of adult patients with iron deficiency anemia.

  4. Macdougall IC. Intravenous iron therapy in patients with chronic kidney disease: recent evidence and future directions. Clin Kidney J. 2017;10(Suppl 1):i16-i24. doi:10.1093/ckj/sfx043

  5. Cleveland Clinic. Oral iron supplementation.

  6. Cortés Buelvas A. Anemia and transfusion of red blood cellsColomb Med (Cali). 44(4):236-242.

By Lana Barhum
Lana Barhum has been a freelance medical writer since 2009. She shares advice on living well with chronic disease.