What are steroids?

Steroids are substances that are naturally produced in the body. 

They help to control many of the different ways our bodies work. They regulate:the way the body uses fats, proteins and carbohydrates

  • the immune system
  • the balance of salt and water in our bodies
  • inflammation.

Steroids can also be made in a laboratory as drugs. They can be used in cancer treatment: 

  • to help destroy cancer cells and make chemotherapy more effective
  • to reduce an allergic reaction to certain drugs
  • as anti-sickness drugs
  • to improve appetite
  • to reduce symptoms such as pain caused by swelling (inflammation) around a cancer.

The most commonly used steroids are:

  • hydrocortisone
  • dexamethasone
  • methylprednisolone 
  • prednisolone.

How steroids are given

You usually have steroids as tablets or liquids that you swallow. But you can also have them as an injection. The dose you have and how long you have the treatment for depends on the reason you are taking steroids.

Tablets or liquids

Swallow steroid tablets with plenty of water or milk. You may need to take the tablets at set times each day. You usually have them in short courses. It is important to make sure you know how long you need to take them for. 

If you have difficulty swallowing, your doctor may prescribe steroid tablets that dissolve in water. Some steroids also come as a liquid syrup. 

Things to remember about steroid tablets:

  • Keep the tablets in a safe place and out of the sight and reach of children.
  • If your doctor decides to stop the treatment, return any remaining tablets to the pharmacist. Do not flush them down the toilet or throw them away.
  • Tell your doctor if you are sick just after taking a tablet, as you may need to take another one.
  • If you forget to take your tablet, do not take a double dose. Ask your doctor or nurse for advice. 
  • If you are having a short course of steroids as part of your treatment, do not get more from your GP.


Steroids can be given by injection in the following ways:

  • into a muscle (intramuscularly)
  • under the skin (subcutaneously)
  • into a vein (intravenously).

If steroids are given into a vein, you have them as a quick injection or as a drip which takes up to 30 minutes. They can be given through:

About side effects

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

You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

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

Contact the hospital

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

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.

Side effects while treatment is being given

If the steroid dexamethasone is given into a vein quickly, it can cause a strange sensation in the area just in front of your back passage (the perineal area). This only lasts for a few seconds.

Possible side effects

Tummy pain or indigestion

Steroids can irritate the stomach lining. Let your nurse or doctor know if you have indigestion or pain in your tummy. They can prescribe drugs to help reduce stomach irritation.

You should take your tablets with food to help protect your stomach. Some steroid tablets are coated to help reduce irritation.

Raised blood sugar levels

Steroids can raise your blood sugar levels. Your nurse will check your blood regularly for this. They may also test your urine for sugar. Symptoms of raised blood sugar include:

  • feeling thirsty
  • needing to pass urine more often
  • feeling tired.

Tell your doctor or nurse if you have these symptoms.

If you have diabetes, your blood sugar levels may be higher than usual. Your doctor can talk to you about this. They may adjust your insulin or tablet dose.

Fluid build-up

You may gain weight, or your face, ankles and legs may swell. This improves slowly after your treatment has finished. Your doctor may give you drugs to help reduce the swelling.

Increased appetite

Steroids can make you feel hungrier than usual and you may gain weight. Your appetite will go back to normal when you stop taking them. If you are worried about gaining weight, talk to your doctor or nurse.

Increased risk of infection

If you are taking high-dose steroids, or having steroids and chemotherapy at the same time, you may have an increased  risk of infection. Tell your doctor if you notice signs of infection. This can include a cough, a sore throat or a temperature above 37.5°C. 

There are things you can do to help reduce the risk of getting an infection. These include: 

  • washing your hands thoroughly before eating, and after using the toilet 
  • avoiding people with an infection, such as a cold
  • avoiding crowds or public places where there is a risk of getting an infection.

Changes to your periods

If you have periods, these may become irregular or stop during treatment. Periods usually return to normal once treatment has finished. This also depends on what other cancer treatments you have, such as chemotherapy.

Mood and behaviour changes

Steroids can affect your mood and behaviour. They can cause:

  • feelings of anxiety or restlessness
  • mood swings (moods that go up and down)
  • low mood or depression.

Sometimes, when taken in higher doses, steroids can cause confusion or changes in thinking. This can include having strange or frightening thoughts.

Tell your doctor or nurse if you notice any changes in your mood or behaviour. They may make some changes to your treatment if the side effects are causing you problems.

Difficulty sleeping

Some people find it more difficult to sleep while taking steroids. Taking your steroids in the morning may help. If you take steroids twice daily, you could take them in the morning and early afternoon.

Less common side effects

We have listed some less common side effects that may develop with long-term use of steroids. Long-term use of steroids is when you take steroids for more than a few months.

Eye changes

Steroids can cause eye problems. There is also an increased risk of eye infections. If you notice any changes to your eyes, such as blurred vision, pain or redness, tell your doctor or specialist nurse.

Changes in your appearance

Steroids can cause changes in your appearance. These can include:

  • acne
  • puffiness of the face
  • facial hair in women
  • dark marks on the skin.

Talk to your doctor if you have any of these side effects. They may be reduced by lowering the dose of steroids.

Effects on muscles

Your muscles may become weaker while you are taking steroids. When you stop taking steroids, you may have muscle cramps for a short time as your body adjusts.

Bone thinning (osteoporosis)

If you are at risk of bone thinning, your doctor may prescribe drugs called bisphosphonates to protect your bones. They will also usually advise you to take vitamin D supplements and to eat foods with lots of calcium in them.

You can also help to protect your bones by:

Tell your doctor if you have any pain in your bones, such as in your lower back.

Other information

If you are taking high-dose steroids or steroids for 3 weeks or more

You will be given a steroid card if you are taking high doses of steroids or steroids for longer than 3 weeks. You should always carry this card. This is so that in an emergency, a doctor will know that you are having steroid treatment.

When the body is under stress, for example during a serious illness or after an injury, it naturally makes extra steroids. These help the body cope better. But, if you have been taking high doses of steroids, or steroids for 3 weeks or longer, your body is less able to make them quickly. This means that if you were unwell or were in an accident, you might need to be given a higher dose of steroids for a while.

After you stop taking steroids, your body will begin to make its own natural steroids again. But it can take a few days for this to happen. So if the steroids you have been taking are suddenly stopped, you may have withdrawal effects. These include:

  • a fever
  • aching muscles or bones
  • feeling generally unwell.

To reduce the risk of withdrawal effects, the dose you take will gradually be reduced before being stopped at the end of your treatment. This gives your body a chance to adjust and get used to making its own steroids again.

It is important to take steroids exactly as prescribed by your doctor.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the doctors and nurses you are having cancer treatment. Give them the contact details for your cancer doctor so they can ask for advice.

If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.