Pegfilgrastim
Say it: peg-fil-GRAH-stim · Brand names: Neulasta, Fulphila, Udenyca, Ziextenzo, Nyvepria, Fylnetra, Stimufend
Pegfilgrastim is a long-acting 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. Pegfilgrastim tells your bone marrow to make more of these cells. It lasts longer in the body than filgrastim, so one shot covers a whole chemotherapy cycle.
Often used for
- lowering the chance of infection after chemotherapy
- radiation sickness after very high radiation exposure
How you get it
It is one shot under the skin, usually given once each chemotherapy cycle, at least 24 hours after chemotherapy ends. Some people get an on-body device that sticks to the skin and gives the dose by itself about a day later. 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.
- Pain in the arms or legs. 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 or where the device was.
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
- If you have the on-body device, keep it away from hot tubs, saunas, and X-rays and other medical scans until the dose is done.
- Check the device light as your team showed you. Call if it blinks red, falls off, or leaks.
- If you give the shot yourself, keep it in the refrigerator. Do not freeze or shake it.
- Put used needles or devices in a hard sharps container.
- If you miss a dose or the device fails, call your team.
Questions to ask
- Will I get the shot in clinic or the on-body device?
- What can I take for bone pain?
- What do I do if the device does not work?
- Do I need this with every cycle?
Part of these treatment plans
Side effect guides
Sources
Quick answers
- What is Pegfilgrastim?
- Pegfilgrastim is a long-acting shot that helps your body make more white blood cells to fight infection. Brand names: Neulasta, Fulphila, Udenyca, Ziextenzo, Nyvepria, Fylnetra, Stimufend.
- What is Pegfilgrastim used for?
- lowering the chance of infection after chemotherapy; radiation sickness after very high radiation exposure.
- How is Pegfilgrastim given?
- It is one shot under the skin, usually given once each chemotherapy cycle, at least 24 hours after chemotherapy ends. Some people get an on-body device that sticks to the skin and gives the dose by itself about a day later. Your schedule may be different.
- What are the common side effects of Pegfilgrastim?
- Bone pain, often in the back, hips, or legs. Pain in the arms or legs. Headache. Feeling tired. Redness or soreness where the shot goes in or where the device was.
- When should I call my care team while taking Pegfilgrastim?
- 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 Pegfilgrastim?
- AC and dose-dense AC, Dose-dense MVAC, FOLFOXIRI, TC.
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.