Denosumab

Denosumab (also known as Prolia®) is a drug treatment for osteoporosis. It can help to strengthen bones, making them less likely to break. It is given as an injection every six months.

Denosumab isn’t usually given as a first treatment for osteoporosis. It’ll probably only be an option if you’ve already tried one of the more common drug treatments, or if other treatments aren’t suitable for you.

What does denosumab do and how does it work?

Denosumab can help to make your bones stronger and reduce your risk of broken bones, including hip and spinal fractures.

Bones are made up of living tissue. The inside of our bones is constantly being broken down and rebuilt by specialist bone cells. As long as this process is in balance, your bones should stay healthy and strong.

But if the process becomes out of balance, our bodies can start to break down more bone than we build. This can cause the bones to become weaker and more likely to break easily.
Denosumab works by blocking the formation and activity of cells that break down bone. This helps to restore the balance and make your bones stronger.

You may still break a bone while taking denosumab. If this happens, it doesn’t necessarily mean the drug isn’t working. No medication can stop all fractures, but taking denosumab will make them much less likely.

Denosumab is not a pain-relieving medicine, so it won’t reduce the pain caused by broken bones. But there are other drug treatments and ways to manage pain.

Who can have denosumab?

Denosumab may be suitable if you have osteoporosis, or if your risk of breaking a bone is high enough to need a drug treatment. You might be offered it as a first treatment. But it will usually only be an option if you’ve already tried a different drug treatment for your bones, or if other drugs aren’t suitable for you.

It is licensed for use in women who have been through the menopause, and for men. Doctors will occasionally offer denosumab to younger women.

Who is denosumab not suitable for?

Denosumab may not be suitable if you:

• have a low blood calcium level (hypocalcaemia) –you’ll need to increase your intake of calcium and vitamin D before you can start denosumab
• have an intolerance to sorbitol (a type of sugar)
• are pregnant or breast-feeding.

How is denosumab given?

You’ll have an injection every six months, usually at the hospital or GP surgery. The injection will be given through a needle just under the skin in either:

• tummy
• the top of your thigh
• your upper arm.

The needle is thin and people often say they feel very little pain.

It’s important to have the injection every six months. This is because the effects of the drug wear off very quickly. You can have injections up to four weeks early or late, if you need to.

You should get a patient reminder card, but it’s a good idea to make a note in your diary or set a reminder on your phone, to help you remember.

Important information - before you start denosumab 

Before you start having denosumab, it’s very important to plan ahead with your doctor. You will need to have another drug treatment if you stop taking it. This is because denosumab wears off quickly.

Some people have had several spinal fractures in the following months after they've stopped denosumab. This is known as the 'rebound effect'. 

To stop the effect, you’ll need to take another drug treatment around the time you were due to have your denosumab injection.

You should have an arrangement with your doctor to make sure you get the other drug treatment in time.

Your doctor will need to refer you to a hospital specialist if they can’t find a suitable drug treatment for you. It’s important to see the specialist with enough time to find a treatment.

You may not need to take another treatment after denosumab if you have been on it for less than two years. But you should make this decision with a specialist, who can talk to you about your options. 

Sometimes your doctor may advise you to stay on denosumab without stopping it. But for most people, if you can’t – or are not willing to – take another drug treatment after denosumab, it probably isn’t the right treatment for you.

How will my treatment be monitored?

You’ll have an appointment every six months to receive your injection. Contact your healthcare professional if you have any problems in between your appointments. They may be able to suggest ways to help manage any side effects (see below).

You should have a blood test before each injection, unless your doctor decides you don’t need one. This is to check your calcium levels, how well your kidneys are working, and sometimes your vitamin D levels. Some people will also have a blood test two weeks after each injection – for example if their kidneys aren’t working as well as they should.

If you break a bone while taking denosumab, speak to your GP. Breaking a bone doesn’t necessarily mean your treatment isn’t working. But it may be a good idea to have a bone health assessment.

After about five years on denosumab you should have a formal treatment review. At this review, your doctor will check if denosumab is still the right treatment for you.

You may have a bone density scan, which will give your doctor some information about your bone strength. But they will need to consider other things as well, such as whether you’ve broken any bones since starting on denosumab.

While there’s no clear way to prove for certain that your treatment is working, research has shown that denosumab does lower the risk of broken bones.

After your review, your doctor may advise you to:

• stay on denosumab for another five years
• change to a different drug treatment – usually a type of drug called a bisphosphonate
• see a specialist if you want to stop denosumab and need advice on what to do next.

How long can I have denosumab?

There is no formal guidance about how long people should have denosumab for. But most people stay on it for several years before moving to a different drug treatment. Your doctor can advise you on what’s best for you, based on your own situation.

Can I stop having denosumab for a while?

No. Denosumab wears off quickly and stops helping your bones when you stop taking it. 

You may have heard the term ‘treatment pause’ when talking about drug treatments. This is where you stop treatment for a year or two, if this is right for you.

It is sometimes an option for people taking a bisphosphonate, such as alendronate or zoledronate. Those drugs keep helping your bones for a while after you stop taking them. But denosumab does not work in this way, so a treatment pause won’t be an option.

What are the possible side effects of denosumab?

As with any drug, denosumab can sometimes cause side effects. The most common side effects are listed below, along with some rare problems that might very occasionally happen after several years of treatment.

It is important to remember that side effects are less common than people think. Most people on denosumab don’t have any problems. Even if you do get side effects at first, they usually improve quickly and there are ways to manage them.

For a full list of possible side effects, look at the patient information leaflet that comes with your treatment. If you don’t have a copy, ask your doctor or pharmacist for one.

It’s important to understand that many of these problems aren’t actually caused by the drug. When a medicine is first tested, the people taking it have to report anything unusual to the researchers. The problems they report are often just as common in people who aren’t taking the drug.

The problems listed in the table below are the main side effects that were seen more often in people on denosumab, rather than a dummy drug. For example, fewer than 1 person in every 100 people who have denosumab will get a severe skin infection. The other 99 in every 100 people who use the drug will not have this problem 

Rare health risks:

If you do get any side effects that don’t go away, it may help to:

• make sure the problem isn’t caused by any other medication you are taking
• tell your doctor or pharmacist, who may be able to help find out what is causing the problem
• ask your doctor or pharmacist about other treatments that may suit you better.

Making a decision about treatment

As with any treatment, there are advantages and disadvantages to using denosumab. You should think about these when deciding whether to have denosumab, and about what’s important to you. Here are some of the main things to consider.

Advantages

• It can help to reduce your risk of broken bones, including in your hips and spine.
• It’s given as an injection, which is helpful if tablets are a problem for you.
• You’ll only have one injection every six months.
• It starts to work quickly and is effective for at least 10 years of use.

Disadvantages

• As with all medications, some people get side effects.
• There are some possible health risks after several years of use, but these are rare.
• The benefits of the drug wear off very quickly if you stop having it.
• Some people don’t like the idea of injections.
• You’ll need to visit the hospital or GP surgery every six months for an injection.

If you've thought carefully about the advantages and disadvantages but still feel unsure, we have more information to help guide you through deciding whether or not to have a drug treatment.

Content reviewed: April 2023 (updated October 2023)