G-CSF (Granulocyte-colony stimulating factor)

G-CSF is a type of protein called a growth factor. It is used to increase the number of white blood cells in the blood.

What is G-CSF?

G-CSF (granulocyte-colony stimulating factor) is a type of protein called a growth factor. 

G-CSF stimulates the bone marrow to make more blood cells, and increases the number of some types of white blood cells in the blood. It can be used with, or after, chemotherapy. It can also be used before and after a stem cell transplant.

G-CSF is made naturally in the body, but it can also be made as a drug. Treatments include:

  • lenograstim (Granocyte®)
  • filgrastim (Accofil®, Neupogen®, Nivestim®, and Zarzio®) 
  • lipegfilgastrim (Lonquex®) 
  • pegfilgrastim (Neulasta®, Pelgraz®, Pelmeg®, and Ziextenzo®).

It is best to read this information with our general information about the type of cancer you have and the treatment you are having.

Your doctor will talk to you about G-CSF and its possible side effects before you agree (consent) to have treatment.

More information about this treatment

This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.

You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.

When G-CSF is used

Chemotherapy

G-CSF is often given with chemotherapy. Chemotherapy can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is sometimes called neutropenia.

The number of white blood cells usually goes back up naturally between the cycles of chemotherapy. But some people need G-CSF to help increase their white blood cell count. This can reduce their risk of infection and mean that chemotherapy can be given on time and at the planned dose.

Collecting stem cells for treatment

A stem cell transplant is sometimes used to treat blood cancers

Stem cells are blood cells at the earliest stage of their development. 

You have a course of G-CSF injections for a few days. This stimulates your bone marrow to make more stem cells. These are then collected, stored and given when the transplant is needed.

How G-CSF is given

G-CSF is usually given as an injection under the skin (subcutaneously). It is usually given into your thigh or tummy area. You, or someone who looks after you, may be shown how to give the injections. Or they can be given by a nurse at home or at the GP surgery.

Some people have G-CSF as a drip into a vein, which takes about 30 minutes. You have this at the hospital or clinic.

During your treatment, you will have regular blood tests to check the number of white blood cells in your body. Your doctor or nurse will explain how often you need the injections. 

Storing G-CSF

Follow any storage instructions given by your pharmacist. Some G-CSF injections should be stored in the fridge. Take the injection out of the fridge 30 minutes before you use it, so it can come up to room temperature.

About side effects

We explain the most common side effects of this treatment here. We also include some that are less common. 

You may get some of the side effects we mention, but you are unlikely to get all of them. And you may have some side effects, including rarer ones, that we have not listed here. 

Other cancer treatments may cause different side effects. If you are also having other cancer treatment, you may have other side effects.

Always tell your doctor, nurse or pharmacist about any side effects you have. They can give you: 

  • drugs to help control some side effects 
  • advice about managing side effects. 

It is important to take any drugs exactly as explained. This means they will be more likely to work for you.

Serious and life-threatening side effects

Some cancer treatments can cause serious side effects. Sometimes, these may be life-threatening. Your doctor, nurse or pharmacist can explain the risk of these side effects to you.

Contact the hospital

Your doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Side effects while treatment is being given

Some people may have side effects while they are being given this treatment or shortly after they have it.

Allergic reaction

This treatment might cause an allergic reaction. But this is not common. Signs of a reaction can include: 

  • a skin rash or itching
  • feeling breathless or wheezy
  • swelling of your face, mouth or throat.

If you feel unwell or have any of these signs, contact the hospital straight away on the 24-hour number. Do not take any more of this treatment until you have checked with them.

Injection site

You may get pain, itching or redness where the injections are given. Having the injection in a different place each time can help with this.

Common side effects

Bone pain

This is caused by your bone marrow making blood cells. You might feel a dull ache in your pelvis (between your hips), your back, arms or legs. Tell your doctor or nurse if you have this. They may suggest medicines to help.

Headaches

This treatment may cause headaches. If you have headaches, tell your doctor, nurse or pharmacist. They can give you advice about painkillers that may help. Tell them if the headache does not get better, or gets worse.

Bruising and bleeding

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot.

If the number of platelets is low, you may bruise or bleed easily. You may have:

  • nosebleeds
  • bleeding gums
  • heavy periods
  • blood in your urine (pee) or stools (poo)
  • tiny red, brown or purple spots that may look like a rash – these spots can be harder to see if you have black or brown skin. 

If you have any unexplained bruising or bleeding, contact the hospital straight away on the 24-hour number. You may need a drip to give you extra platelets. This is called a platelet transfusion.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may feel:

  • very low in energy
  • breathless 
  • dizzy and light-headed. 

If you have these symptoms, contact the hospital straight away on the 24-hour number. You may need treatment for anaemia. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Fever and chills

You may get fever and chills as a side effect of G-CSF. If you notice this, tell your doctor or nurse. They may suggest medicines to help.

If you are having chemotherapy

G-CSF is often given with chemotherapy. Chemotherapy can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is sometimes called neutropenia.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. Contact the hospital straight away on the 24-hour contact number you have been given if:

  • your temperature goes over 37.5°C (99.5°F) 
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection
  • your temperature goes below 36°C (96.8°F). 

Symptoms of an infection include:

  • feeling shivery and shaking
  • a sore throat
  • a cough 
  • breathlessness
  • diarrhoea
  • needing to pass urine (pee) a lot, or discomfort when you pass urine.

It is important to follow any specific advice your cancer treatment team gives you.

Feeling sick and loss of appetite

You may feel sick or not feel like eating while having G-CSF treatment. If this happens, talk to your doctor or nurse. They can give you anti-sickness drugs to help.

Constipation

This treatment can cause constipation. Constipation means that you are not able to pass stools (poo) as often as you normally do. It can become difficult or painful. Here are some tips that may help:

  • Drink at least 2 litres (3½ pints) of fluids each day.
  • Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
  • Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital on the 24-hour number for advice. They can give you drugs called laxatives to help. 

If you have not been able to pass stools for over 2 days and are being sick, contact the 24-hour number straight away. 

Diarrhoea

This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is normal for you, or having watery or loose stools. You may also have stomach cramps. If you have a stoma, it may be more active than usual. 

If you are passing loose stools 3 or more times a day and this is not normal for you, contact the hospital as soon as possible on the 24-hour number. Follow the advice they give you about:

  • taking anti-diarrhoea medicines 
  • drinking enough fluids to keep you hydrated and to replace lost salts and minerals
  • any changes to your diet that might help. 

They might also ask you for a specimen of your stool to check for infection.

Tummy pain

You may get mild pain or discomfort in your tummy (abdomen). Tell your doctor or nurse if you have this. They may give you medicines to help.

Pain in left side of tummy or shoulder

The spleen is on the left side of the tummy (abdomen), just under the ribs. The spleen helps fight infection and also stores and breaks down blood cells.

G-CSF can cause your spleen to grow bigger. This is usually mild and goes away after you stop treatment. Symptoms of an enlarged spleen include discomfort on the left side of the tummy or shoulder, and feeling full quickly when eating. If you notice this, tell your doctor or nurse.

Skin changes

This treatment may affect your skin. It may cause a rash, which might be itchy. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day.

Always tell your doctor or nurse about any changes to your skin. They can give you advice and may prescribe creams or medicines to help. Skin changes usually improve when treatment finishes.

Very rarely, this treatment may cause a more serious skin condition. You may have a skin rash which then blisters and your skin can peel. You may also feel unwell with flu-like symptoms such as a high temperature and joint pain. If this happens, contact the hospital straight away.

Less common side effects

Effects on the liver

This treatment may affect how your liver works. This is usually mild. You will have blood tests to check how well your liver is working.

Effects on the kidneys

This treatment can affect how your kidneys work. This is usually mild and goes back to normal after treatment finishes. You will have blood tests to check how well your kidneys are working. You may also have urine tests. Tell your doctor or nurse if you have blood in your urine (pee) or you are passing urine less than usual.

It is important to drink at least 2 litres (3½ pints) of non-alcoholic fluid each day to help protect your kidneys. 

Build-up of fluid

This may lead to swelling of the ankles or feeling breathless. Talk to your doctor or nurse if you notice this. They may give you medicines to help.

Effects on the lungs

This treatment can cause changes to the lungs. Tell your doctor, nurse or pharmacist if you develop: 

  • a cough that does not go away
  • wheezing
  • breathlessness.

You should also tell them if any existing breathing problems get worse. You may have tests to check your lungs.

Dizziness

This treatment may cause you to feel dizzy (light-headed). If you notice this, do not drive or operate any machinery

Sleep problems

This treatment may cause sleep problems. If you notice this, tell your doctor or nurse. They can suggest things to help.

Other information

G-CSF is a growth factor. This means that in some people, it may cause cancer to progress or grow. Your doctor will consider the benefits and risks of this treatment before deciding whether it is suitable for you. Your doctor will talk to you about this. If you have any concerns or questions, always talk to your doctor or nurse.

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

  • throbbing pain or swelling in a leg or arm
  • reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
  • suddenly feeling breathless or coughing.

Always call 999 if you have:

  • chest pain
  • difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

Other medicines

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

Sorbitol

Some G-CSF injections contain a sugar called sorbitol. If you have an intolerance to some sugars, talk to your doctor before taking G-CSF.

Contraception

Your doctor, nurse or pharmacist will advise you not to get pregnant or make someone pregnant while having this treatment and for some time afterwards. The drugs may harm a developing baby. It is important to use contraception to prevent pregnancy. Follow their advice about:

  • what types of contraception to use 
  • how long after treatment you should continue to use contraception. 

Breastfeeding

You are advised not to breastfeed while having this treatment, or for some time after treatment ends. This is because the drugs could be passed to the baby through breast milk. 

Your doctor, nurse or pharmacist can give you more information.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

  • use plain English
  • explain medical words
  • use short sentences
  • use illustrations to explain text
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We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.

Date reviewed

Reviewed: 01 October 2022
|
Next review: 01 April 2025
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.