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Granulocyte colony stimulating factor (G-CSF)

Find out what G-CSF (granulocyte colony stimulating factor) is, how you have it and other important information about having G-CSF.

G-CSF is a type of growth factor.

Growth factors are proteins made in the body and some of them make the bone marrow produce blood cells. G-CSF makes the bone marrow produce white blood cells to reduce the risk of infection after some types of cancer treatment. 

G-CSF also makes some stem cells move from the bone marrow into the blood. Stem cells are the cells in the bone marrow that make red blood cells, white cells and platelets.

There are different types of G-CSF, including:

  • lenograstim (Granocyte)
  • filgrastim (Neupogen, Zarzio, Nivestim, Ratiograstim)
  • long acting (pegylated) filgrastim (pegfilgrastim, Neulasta) and lipegfilgrastim (Longquex)

Pegylated G-CSF stays in the body for longer so you have treatment less often than with the other types of G-CSF.

When you might have G-CSF

You might have G-CSF after chemotherapy to help your white blood cells recover after treatment.

Or you might have G-CSF before and after a stem cell transplant.

Before the treatment you have G-CSF to stimulate the bone marrow to produce stem cells and release them into the blood. The stem cells are collected and then you have high dose chemotherapy.

The chemo stops your bone marrow producing blood cells. So you have the stem cells back into your blood stream. They go into the bone marrow and start making the different types of blood cells again. 

How you have G-CSF

You can have G-CSF as an injection under the skin or into your bloodstream.

G-CSF as an injection under the skin 

Most people have G-CSF as an injection just under their skin (subcutaneously). You usually have this daily. Your nurse can teach you, or a family member or friend, how to give this yourself. It comes as a ready filled syringe so it is simple to give.

Into your bloodstream

You have the treatment through a drip into your arm. A nurse puts a small tube (a cannula) into one of your veins and connects the drip to it.

You might need a central line. This is a long plastic tube that gives the drugs into a large vein, either in your chest or through a vein in your arm. It stays in while you’re having treatment, which may be for a few months.

Tests during treatment

You have blood tests before starting treatment and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

Side effects

Find out about possible side effects of G-CSF and what to do if you have them.

Important information

Other medicines, foods and drink

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.

Pregnancy and contraception

This treatment might harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment and for a few months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.


Don’t breastfeed during this treatment because the drug may come through in your breast milk.

Treatment for other conditions

Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment if you need treatment for anything else, including teeth problems.


Don’t have immunisations with live vaccines while you’re having treatment and for at least 6 months afterwards.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and shingles vaccine (Zostavax).

You can:

  • have other vaccines, but they might not give you as much protection as usual
  • have the flu vaccine
  • be in contact with other people who've had live vaccines as injections

Avoid contact with people who’ve had live vaccines taken by mouth (oral vaccines). This includes the rotavirus vaccine given to babies. The virus is in the baby’s urine for up to 2 weeks and can make you ill. So, avoid changing their nappies for 2 weeks after their vaccination if possible. Or wear disposable gloves and wash your hands well afterwards.

You also need to avoid anyone who has had oral polio or typhoid vaccination recently.

Storing G-CSF

You need to keep your ready-filled syringes in the fridge between 2 and 8°C, except for lenograstim, which is stored at room temperature.

More information about this treatment

For further information about this treatment go to the electronic Medicines Compendium (eMC) website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

Information and help

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