Filgrastim
Say it: fil-GRAH-stim · Brand names: Neupogen, Zarxio, Nivestym, Releuko, Nypozi
Filgrastim is a shot that helps your body make more white blood cells to fight infection.
What it is
Chemotherapy can lower your white blood cells, which fight germs. Filgrastim is a man-made copy of a natural protein that tells your bone marrow to make more of these cells. This helps your white blood cell count come back faster.
Often used for
- lowering the chance of infection after chemotherapy
- helping blood counts recover after a bone marrow or stem cell transplant
- moving stem cells into the blood so they can be collected
- some types of leukemia treatment
- long-term low white blood cell counts
- radiation sickness after very high radiation exposure
How you get it
It is usually a shot under the skin, and sometimes a drip into a vein. It is often given once a day for several days after chemotherapy, until your counts come back up. Your schedule may be different.
Common side effects and what helps
- Bone pain, often in the back, hips, or legs. Ask your team which pain medicine is safe for you.
- Muscle or joint aches. A warm shower or heating pad may help.
- Headache. Rest and drink fluids.
- Feeling tired. Plan rest breaks during the day.
- Redness or soreness where the shot goes in. Change spots each time.
- Fever. Always check your temperature and call if it is 100.4 degrees Fahrenheit or higher.
Call your care team right away if you have
- Pain in the upper left belly or the tip of the left shoulder. This can be a sign of a spleen problem.
- Trouble breathing, fast breathing, or a cough that is new
- Signs of an allergic reaction, like a rash all over, swelling of the face or throat, or wheezing
- A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher
- Swelling or puffiness, peeing less than usual, or feeling dizzy or faint
- Very bad pain in the back, chest, or belly with a fever
Before you start, tell your team
- If you have sickle cell disease or sickle cell trait
- If you have ever had a reaction to filgrastim, pegfilgrastim, or similar medicines
- If you have kidney problems
- If you are allergic to latex. Some needle covers contain latex.
- If you are pregnant, may become pregnant, or are breastfeeding
Good to know
- Rarely, the spleen can get bigger and break open. Call right away for pain in the upper left belly or left shoulder.
- Rare but serious problems can affect the lungs, kidneys, and blood vessels. Your team will watch for these.
- People with sickle cell disease can have a serious sickle cell crisis.
- You will have blood tests to check your white blood cell count.
- In some people with breast or lung cancer, this medicine has been linked to a small risk of later blood cancers. Ask your team what this means for you.
At home
- Your team will show you or a family member how to give the shot.
- Keep it in the refrigerator. Do not freeze or shake it. Let it sit out for about 30 minutes before the shot.
- Use the belly, thighs, or back of the upper arms, and change spots each time.
- Put used needles in a hard sharps container.
- If you miss a dose, ask your team what to do.
Questions to ask
- How many days will I need these shots?
- What can I take for bone pain?
- Who will teach me to give the shot?
- When will my blood counts be checked?
Part of these treatment plans
Side effect guides
Sources
Quick answers
- What is Filgrastim?
- Filgrastim is a shot that helps your body make more white blood cells to fight infection. Brand names: Neupogen, Zarxio, Nivestym, Releuko, Nypozi.
- What is Filgrastim used for?
- lowering the chance of infection after chemotherapy; helping blood counts recover after a bone marrow or stem cell transplant; moving stem cells into the blood so they can be collected; some types of leukemia treatment; long-term low white blood cell counts; radiation sickness after very high radiation exposure.
- How is Filgrastim given?
- It is usually a shot under the skin, and sometimes a drip into a vein. It is often given once a day for several days after chemotherapy, until your counts come back up. Your schedule may be different.
- What are the common side effects of Filgrastim?
- Bone pain, often in the back, hips, or legs. Muscle or joint aches. Headache. Feeling tired. Redness or soreness where the shot goes in. Fever.
- When should I call my care team while taking Filgrastim?
- Pain in the upper left belly or the tip of the left shoulder. This can be a sign of a spleen problem; Trouble breathing, fast breathing, or a cough that is new; Signs of an allergic reaction, like a rash all over, swelling of the face or throat, or wheezing; A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher; Swelling or puffiness, peeing less than usual, or feeling dizzy or faint; Very bad pain in the back, chest, or belly with a fever.
- Which chemotherapy plans include Filgrastim?
- CLAG-M, DA-EPOCH-R, FLAG-IDA.
Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.