What is Caverject?

Caverject is a treatment for erectile dysfunction, administered via an injection to the base of the penis. There are two different versions: Caverject Vials and Caverject Dual Chamber.

How does Caverject work?

In Caverject is a substance called alprostadil, which is the active ingredient.

Erectile dysfunction is caused by constricted blood vessels, hindering the flow of blood to the penis.

When injected into the body, alprostadil helps to widen these blood vessels. This increases blood flow to the penis and helps to produce an erection.

How long does Caverject take to work?

The reaction time from administration to erection is usually between 5 and 20 minutes.

How long does Caverject last for?

In the majority of cases, the effects of Caverject will last for up to an hour.

Who should use Caverject?

Caverject is better suited to patients who are not able to use oral treatments for erectile dysfunction, such as Cialis or Viagra.

It might also be considered as a treatment in patients for whom oral medicines haven't worked.

How are Caverject Vials and Dual Chamber different?

Caverject Dual Chamber comes in one device ready to be mixed; whereas in Caverject Vials, the drug comes as a powder which needs to be mixed with the solution, provided in the pack separately.

Read more about the differences between Caverject Vials and Dual Chamber.

What doses are available?

Caverject Vials are available in 10mcg, 20mcg and 40mcg doses.

Caverject Dual Chamber is available in 10mcg and 20mcg injections.

How often can I use Caverject?

You should never administer more than one dose of Caverject in any 24 hour period, and it shouldn’t be used more than three times in a week.

Who makes Caverject?

Pfizer both manufacture and market Caverject.

Do I need a prescription for Caverject?

Yes. It is not possible to purchase Caverject in the UK over the counter, or without a prescription.

A doctor must first assess the suitability of Caverject before issuing a prescription for it to a patient. Before first use, it is also important for a doctor or nurse to demonstrate in person to the patient how to administer it.

Is Caverject safe?

Yes. Before any medication is approved and made available for use, it is put through rigorous clinical testing to ensure it is safe.

However, like any medicine, it isn’t suitable for everyone.

You should only ever buy Caverject from a registered UK pharmacy, who will undertake the proper checks to make sure it is suitable for you. It’s also absolutely vital to make sure you apply the injection correctly, and to carefully follow the instructions given by your doctor or nurse when they show you how to use it.

Does Caverject have any side effects?

As with any drug, some side effects have been reported with the use of Caverject.

Pain in the penis is listed as the most common. Other common side effects include bruising at the site of the injection, as well as swelling; although these are less likely to happen the more familiar the user becomes with giving themselves the injection.

You can find more information on side effects in the patient information leaflet.

Is there anyone who shouldn’t use Caverject?

Yes. People who have scarring or a deformity of the penis shouldn’t use it. It is also not suitable for patients who have an implant in their penis, or have a condition which puts them at increased risk of priapism (prolonged erections), such as sickle cell anaemia or leukaemia.

It also shouldn’t be used by anyone who has an allergy to any of the ingredients in it.

For more information on who shouldn’t use Caverject, consult the patient information leaflet, or ask your doctor.

Will Caverject interact with other medicines?

Caverject can cause interactions with high blood pressure medicines, treatments used in heart disease, and blood thinning medications like warfarin.

It also shouldn’t be used in conjunction with other treatments for ED, including any prescription medicines or herbal remedies.

Once again, more info is available in the product leaflet.

Can I get Caverject on the NHS?

Some men can, yes.

Patients who have a condition such as Parkinson’s disease, diabetes or multiple sclerosis, are entitled to ED treatment on an NHS prescription.

However, the majority of men will need to obtain a prescription for the treatment privately, and pay for it.

You can read more on our How to buy Caverject page.

Can I get generic Caverject?

No. There is no generic version of Caverject licensed in the UK at present; at time of writing, the patent license on this medicine was still in effect.

There are other treatments, such as Viridal and MUSE, which contain the same active ingredient.

Which other drugs are similar to Caverject?

Viridal is an injectible treatment for ED, which contains the same active ingredient as Caverject and is available in the same dosage integers.

MUSE and Vitaros also contain alprostadil, the functioning agent in Caverject, but are administered differently.

How effective is Caverject?

The efficacy of Caverject has been investigated in clinical trials.

In one study, involving 153 participants, 76 percent responded to the medication; and 73 percent of men who self-administered the treatment achieved an erection sufficient for ‘satisfactory intercourse’.

In another study, involving 683 men, 87 percent of injections resulted in an erection suitable for ‘satisfactory intercourse’.

Does Caverject work better than Viagra?

It’s difficult to give a true comparison of the two, as their clinical efficacy is reported in slightly different ways; the response rates recorded for Viagra are given as ‘improved erections’; while the Caverject results are given as erections suitable for satisfactory intercourse.

The dosing for the two treatments is also a factor to consider. Viagra is usually given as a 25mg or 50mg starting dose, whereas treatment with Caverject is titrated (begun at a low dose and gradually increased).

While these studies give an overall representative view of their efficacy, how they work on an individual basis can depend on a number of factors; so it’s always better to check with your doctor to see which treatment they recommend before drawing any conclusions.

Read more about the advantages of Caverject.

What should I do if Caverject doesn’t work?

Tell your doctor. They will be able to review the dosage you are using and adjust it where necessary; or recommend an alternative treatment where required.

Can I read Caverject reviews online?

It is possible to read online Caverject reviews on forums and drug review sites. However, every patient is different; it's important to remember that what works (or doesn't work) for someone else may not necessarily work (or fail to work) for you, which is why it is important to speak to a doctor if you are not sure. 

Can I get it online?

Yes. Caverject is available to buy online. When you purchase it from Treated.com, you will be asked to complete a short consultation with a doctor, who will issue a prescription if suitable.

If you haven’t used Caverject before, you shouldn’t buy it online without speaking to your doctor in person first. They may suggest trying another medicine for ED first, and if they do decide to prescribe Caverject, they will need to show you how to use the injection.

Page last reviewed:  24/08/2018 | Next review due:  02/07/2020