Oncology Certified Nurse Practitioner and freelance healthcare writer with over a decade of medical oncology and hematology experience.

David Snyder, PharmD, BCPP, is a board-certified clinical pharmacist and psychopharmacology expert at McLean Hospital in Belmont, Massachusetts.

Zejula has the potential to cause harm to an unborn fetus and should not be taken during pregnancy.

It also carries the risk of causing bone marrow disorders such as myelodysplastic syndrome or a type of leukemia called acute myeloid leukemia.

Zejula (niraparib ) is an oral cancer medication called a poly (ADP-ribose) polymerase (PARP) inhibitor. It is used in adults to treat certain types of cancer that affect the ovaries and fallopian tubes.

PARP is an enzyme that repairs DNA damage in cells. By blocking PARP from working in cancer cells, they are prevented from repairing the DNA, which causes the cancer cell to die.  

Zejula comes in capsule form.

Brand Name(s): Zejula

Therapeutic Classification: Antineoplastic agent

Controlled Substance: N/A

The Food and Drug Administration (FDA) approved Zejula to treat ovarian cancer, which can also include cancer in the fallopian tubes and the pelvis area called the peritoneum. It is used as maintenance therapy, usually following an initial round of treatment for cancer.

Zejula can be used to:

Evidence supports the use of Zejula as first-line maintenance therapy for advanced ovarian cancer to help prevent a recurrence. For example, a recent placebo-controlled phase 3 trial in people with newly diagnosed advanced ovarian cancer found that the drug significantly reduced the risk of disease progression or death when used as first-line maintenance therapy in people who responded to platinum-based chemotherapy.

Zejula should be taken once a day, around the same time every day. It can be taken with or without food. Only swallow the capsules whole; do not open or crush them.

Zejula can sometimes cause nausea as a side effect. Taking your dose at bedtime can help reduce nausea symptoms.

Store Zejula at room temperature (between 68 and 77 degrees F) and keep it in its original container. It is important to keep your medication away from the reach of children.

Zejula may be given for a few months to allow it time to work before the oncologist orders any imaging studies to check the progression of your cancer and how well the medication is working.

This is not a complete list of side effects and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your healthcare provider. You may report side effects to the FDA at fda.gov/medwatch or 1-800-FDA-1088.

As with most medications, side effects can occur while taking Zejula.

The most common side effects of Zejula include:

Call your healthcare provider right away if you experience any serious side effects from Zejula. Call 911 if you feel your symptoms are life-threatening. Serious side effects and their symptoms can include the following:

Taking Zejula can potentially increase the risk of developing a bone marrow disorder, myelodysplastic syndrome, or acute myeloid leukemia. 

Signs and symptoms of these conditions can include:

Zejula may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

You may need a dose modification of Zejula if you experience side effects that aren’t well controlled or if you have liver disease.

If you miss your dose of Zejula, take it at the next scheduled time. Do not double up on doses to make up for the missed dose.

Zejula can sometimes cause nausea as a side effect. If you vomit after taking a dose, do not take an extra dose. Take your next dose at the scheduled time.

Contact your cancer care team immediately if you take more than the prescribed amount of Zejula. 

If you think you or someone else may have overdosed on Zejula, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses, has a seizure, has trouble breathing, or can’t wake up after taking too much Zejula, call 911 immediately.

It is very important that your doctor check your progress at regular visits. This will allow your doctor to see if the medicine is working properly and to decide if you should continue to take it. Blood tests may be needed to check for unwanted effects.

Using this medicine while you are pregnant can harm your unborn baby. If you are a woman who can get pregnant, your doctor may do tests to make sure you are not pregnant before starting treatment. Use an effective form of birth control to keep from getting pregnant during treatment and for at least 6 months after the last dose of this medicine. If you think you have become pregnant while using the medicine, tell your doctor right away.

This medicine may cause bone marrow problems, including myelodysplastic syndrome or acute myeloid leukemia. Check with your doctor right away if you have a fever, blood in the urine or stool, chills, unusual bleeding, bruising, tiredness, or weakness, or weight loss.

Niraparib can temporarily lower the number of white blood cells in your blood, increasing the chance of getting an infection. It can also lower the number of platelets, which are necessary for proper blood clotting. If this occurs, there are certain precautions you can take, especially when your blood count is low, to reduce the risk of infection or bleeding:

If you plan to have children, talk with your doctor before using this medicine. Some men using this medicine have become infertile (unable to have children).

Your doctor will check your blood pressure on a regular basis while you are using this medicine. You might need to monitor your blood pressure at home. Tell your doctor right away if you have a severe headache, lightheadedness, or changes in your vision.

Check with your doctor right away if you have agitation, back pain, blurred vision, change in consciousness, confusion, dizziness, drowsiness, fever, hallucinations, headache, irritability, loss of consciousness, mood or mental changes, seizures, stiff neck, unusual tiredness or weakness, or vomiting. These may be symptoms of a serious nervous system problem called posterior reversible encephalopathy syndrome (PRES).

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

Do not take Zejula during pregnancy, as it can cause harm or death to the unborn fetus. Avoid taking Zejula while breastfeeding, as well.

People who are allergic to FD&C Yellow No. 5 (an artificial food coloring commonly used to dye tablets and capsules) should not take Zejula.

No studies specifically looking at drug interactions with Zejula have been done. 

However, any medication that could cause similar serious side effects as Zejula may need to be reviewed by your healthcare provider.

In addition to Zejula, other PARP inhibitor medications include:

These medications should not be taken along with Zejula. 

Zejula is used to treat advanced ovarian cancer in people who have previously received a type of chemotherapy called platinum chemotherapy. It is typically used to prevent cancer from recurring after a person has responded to chemotherapy.

Zejula is a PARP inhibitor. It blocks the action of the PARP enzyme in cancer cells. The PARP enzyme repairs the DNA in a cell, and by blocking it, the cancer cell dies.

Some side effects from Zejula can include the following:

Do not stop taking Zejula unless instructed by your oncologist.

Zejula can be an effective part of your cancer medication plan. It can help treat ovarian cancer and keep it from returning when used as maintenance therapy. 

When starting your cancer treatment, it is important to communicate with your cancer care team about any questions, concerns, or feelings you have. They can help you navigate your cancer journey. 

Talk to your healthcare providers if you’re experiencing any side effects from the medication. They can help provide you with tips to manage your symptoms. 

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

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Food and Drug Administration. Zejula label.

National Cancer Institute. PARP inhibitor.

Lee A. Niraparib. A review in first-line maintenance therapy in advanced ovarian cancer. Targeted Oncology. 2021. doi:10.1007/s11523-021-00841-2

Food and Drug Administration. Lynparza label.

Food and Drug Administration. Rubraca label.

Food and Drug Administration. Talzenna label.

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