Difficulty getting and keeping an erection

Certain prostate cancer treatments can make it difficult to get and keep an erection. Find out why this happens and which treatments can help. 

What causes erection problems?

Certain prostate cancer treatments can damage the nerves that you need to get an erection. Other treatments can affect the levels of hormones needed to get and maintain an erection.  


Surgery to remove the prostate gland (radical prostatectomy) can cause erection problems. Nerve sparing surgery can help lower the risk of this. But not everyone is suitable for this type of surgery. Nerve sparing surgery means that your surgeon is able to remove your cancer without cutting or damaging the nerves that run alongside the prostate gland.

Some men will get back their ability to have erections. But this can take time. It may take anything between 3 months to 3 years to get back your erections after a radical prostatectomy. You might always need help to get an erection.

Hormone therapy

Hormone therapy lowers the amount of testosterone in the body and this affects your ability to have and maintain an erection. If you stop the injections or tablets, the erections may improve.


Radiotherapy to the prostate has a more delayed effect. Men can develop erection problems up to 2 years after finishing treatment.

High Intensity Focused Ultrasound (HIFU) or cryotherapy

Treatments such as High Intensity Focused Ultrasound (HIFU) or cryotherapy may cause fewer erection problems. Researchers are still looking into these treatments and their long term side effects. There is still a risk of erection problems with these treatments. For example, to treat your cancer properly, the doctor may not be able to avoid the nerves. 

Treatments for erection problems and penile rehabilitation

Different treatments work for different people and they can have side effects. Talk through your options with a doctor or nurse with expertise in this area.  Ask them to refer you to your local Erectile Dysfunction Clinic if they are not able to give you this specialist advice.  

As well as causing erection difficulties, surgery and radiotherapy can cause a shortening in the length and width of the penis. So treatments for erection difficulties are part of a programme called penile rehabilitation. This is also called erectile dysfunction rehabilitation.

The aim of penile rehabilitation is to:

  • maintain blood flow to the penis
  • reduce damage to the muscle and tissue in the penis
  • provide a stimulus for erections

Using and stimulating the penis keeps the tissues active and prevents them from becoming inflexible

This can hopefully help you to adapt to changes in your sexual function and relationships.

A penile rehabilitation programme includes:

  • counselling and sex therapy
  • taking tablets
  • using a vacuum pump (vacuum constriction device)
  • trying a cream
  • pellet injections into the shaft of the penis
  • healthy living such as exercise, weight control not smoking and pelvic floor exercises

Why is rehabilitation important?

Whether you are single, or in a relationship, you should have the opportunity to discuss penile rehabilitation with your doctor or specialist nurse. Self pleasuring (masturbation) is important for many people and this can play a part in rehabilitation. This might help to give you confidence and to become aware of the changes that your treatment might have caused.

It might still be worth talking to your doctor even if you are not sexually active, or don’t plan to be. This is because penile rehabilitation has benefits in terms of keeping the penis healthy.

Ideally, rehabilitation should start soon after your prostate cancer treatment, or in some situations before treatment. For example, you should start rehabilitation within 3 to 6 months of starting hormone therapy or radiotherapy. Or within the first 3 months of surgery to remove the prostate gland.  

Talking, counselling and sex therapy

Talking to your partner about your erection difficulties can help. Or it may help to talk to a close friend if you are not in a relationship.

Not talking to those close to you could be one of the main barriers to coping with this side effect. You might then find it easier to consider ways that could help.

Counsellors or therapists can help if you’re worrying about anything to do with your sex life and sexuality. You can be referred by your GP to a counsellor or therapist within the NHS. You might need to go on a waiting list to see them.

Talk to your GP to find out what is available in your area. Your local hospital or your local Erectile Dysfunction Clinic might have this service.

Taking tablets

The drugs used to treat erection problems include:

  • tadalafil (Cialis)
  • sildenafil citrate (Viagra)
  • vardenafil (Levitra)
  • avanafil (Spedra)

These belong to a group of drugs called phosphodiesterase type 5 (PDE 5) inhibitors. They work by increasing blood flow to the penis. For the drugs to work, men need to be aroused and have some sort of sexual stimulation. In other words, the drugs won’t cause an immediate erection, some foreplay is usually needed.

As drugs work best in men who have sexual desire, they might not help some men who are having hormone therapy. There is limited evidence to say these drugs work when having hormone therapy. But some specialists believe that they are still worth a try if you would like to give them a go.

Talk to your doctor about the best PDE 5 drug for you and the best way to take it. Tadalafil works for 24 to 36 hours, whereas the other drugs work for up to 4 to 6 hours. It’s worth knowing that some men need to take 5 to 6 doses before they start to have an effect. You take a daily dose, or when you need them.

Possible side effects of PDE 5 inhibitors include:

  • headaches
  • dizziness
  • temporary problems with vision

These drugs should not be taken with medicines called nitrates. Nitrates are used to treat heart problems such as angina and are in some recreational drugs (poppers). Taking the 2 drugs together could have serious side effects.

Funding for some of these drugs and treatments are limited on the NHS. So your GP might only prescribe a limited amount of these drugs. For example, not enough for a daily dose. Or you may not be able to get a vacuum pump via your GP. If this is the case and you are able to, ask your doctor how you can buy these privately.

Vacuum pumps

Vacuum pumps are also called vacuum constriction devices (VCDs). The pump fits over the penis and draws blood into the penis to form the erection.

You can then put a soft plastic ring called a constriction ring around the base of your penis. The ring keeps the erection firm. The ring should not be left on for more than 30 minutes. As the ring restricts blood flow, using it for a longer period of time could cause damage to the tissues.

Vacuum pumps can work well with practice, but they don't suit everyone. It’s worth knowing that the pump can cause the penis to have a blue tinge, this is normal. You can use a vacuum pump without the ring to exercise the penis as an important part of a penile rehabilitation. 

First of all, your doctor might suggest you try using the vacuum device in combination with the PDE 5 drugs. The exception to this is men who have had a radical prostatectomy and the surgeon has not been able to avoid the nerves (non nerve sparing surgery). PDE 5 drugs do not work so well in this situation. So you might have a vacuum pump alone. Or the pump combination with other treatments described below.  

Your doctor might suggest creams, injections or pellets if PDE 5 drugs and a vacuum device have not worked.


The topical cream is called alprostadil or Vitaros. Topical means a cream that you put on to the skin. You use an applicator to put this cream on to the opening at the end of the penis. If the cream works for you, you get an erection within around 5 to 30 minutes and it can last for 1 to 2 hours. 

Injections or pellets

The injection contains the drug alprostadil, also known as Caverject or Viridal Duo. You put the injection into the shaft of the penis. Or if you have a partner, you might prefer them to do it. You are shown how to do this by your doctor or specialist nurse. If it works, you get an erection within 10 minutes of having the injection.

Pellets containing alprostadil are available and are called MUSE. They are about the size of a grain of rice. You put them in the opening at the end of your penis, using a small plastic device. The pellet is absorbed into the surrounding tissue. It takes about 30 minutes. Again your specialist doctor or nurse can teach you how to use them.


Implant surgery is usually only used if other methods of treating your erection problems haven't worked. Implants are put into the penis during a short operation. Penile implants can be grouped into 2 main types:

  • inflatable implants
  • semi rigid malleable (positional) rods

The most commonly used type of inflatable implant is made up of a pair of hollow cylinders, a pump and a small bag of saline. Your surgeon puts the cylinder part of the implant into the part of your penis that becomes erect. They put the pump into your scrotum. And the small bag of saline is put behind your tummy (abdominal) muscles.

When you want an erection you squeeze the pump, and the saline moves into your penis making it erect. When you no longer want an erection you press a valve and the saline moves back into the bag behind your tummy (abdominal) muscles.

Semi rigid malleable (positional) rods are two flexible rods that your surgeon puts into the part of your penis that becomes erect. Your penis will be erect all the time, but the implant has joints that allow you to position your penis. You can position your penis up for sexual intercourse and down to pass urine.  

Healthy living

Making changes to how you live your life can help you feel better and could improve your sex life. Research has shown that being active and having a healthy weight can improve a man’s interest in sex and help towards achieving an erection. Not smoking can also improve erections in men who have previously smoked.

Pelvic floor muscles are the sling of muscles in between your legs that run from the tail bone at the back to the pubic bone at the front.  These muscles support the bladder and bowel. At the moment, there is no evidence to say that pelvic floor exercises can help erection problems. But some specialists think that they might help. They are worth doing anyway because these exercises can prevent or reduce leakage or urine (urinary incontinence).

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