Medically reviewed by
Dr. IkejiLast reviewed: 12 Sept 2025
Alprostadil for Erectile Dysfunction
Alprostadil is an effective erectile dysfunction treatment that is available as an injection or cream. It is a synthetic prostaglandin E1, which is a potent and short-lasting vasodilator. Alprostadil works for erectile dysfunction because it opens up the blood vessels, increasing blood flow to the penis, enabling you to get and keep an erection.
In this guide, we’ll discuss how alprostadil works for erectile dysfunction, its available forms, typical dose, potential side effects, and how it compares to other ED treatments.
How does alprostadil treat erectile dysfunction?
Alprostadil is a synthetic version of the hormone, prostaglandin E1, which naturally occurs in the body. It’s a vasodilator, which means that it widens blood vessels. Alprostadil works for erectile dysfunction because it widens the blood vessels in the penis by relaxing the smooth muscles to increase blood flow, resulting in an erection that’s good enough for sex.
Alprostadil usually works within 30 minutes and can last for 1 to 2 hours. It’s usually a second-line erectile dysfunction treatment after phosphodiesterase type-5 (PDE-5) inhibitors, like Viagra and Cialis.
Available forms of alprostadil
Alprostadil is available in several forms to treat erectile dysfunction, including as a cream, injection, and a urethral suppository. The best option for you depends on several factors, including how quickly you need it to work and the possibility of side effects.
Injection
Alprostadil injection, also known as Caverject, is an intracavernosal injection which can be injected by yourself into the base of the penis. One study found that alprostadil injections helped 94% of people with ED have sex, and that satisfactory sex was achieved after 87% of injections.
Although effective, research shows that alprostadil injections have a high dropout rate of between 41 and 68%. It is also the most expensive form of alprostadil.
Cream
Alprostadil cream, available under the brand name Vitaros, is an effective non-tablet and non-injection erectile dysfunction treatment. It is effective in 31 to 40% of people.
Alprostadil cream is applied directly into the urethra using an applicator. Although clinical data shows that alprostadil cream is less effective than injection, it may be a preferred and less invasive solution for some people.
Urethral suppository
Alprostadil is also available as a urethral suppository known as MUSE (medicated urethral system for erection). It is available as a pellet, which is applied via an applicator directly in the urethra. Your doctor or nurse should show you how to use the alprostadil suppository for the first time. Clinical trial data shows that MUSE has a success rate of 56%.
The same trial found that in the 44% of people that the treatment failed for:
- 61% was due to a lack of effectiveness
- 39% was due to side effects, including genital pain and bleeding
Dose and administration
The alprostadil dose you’ll require will depend on which form you are given to treat erectile dysfunction. Your doctor will discuss the correct dose for you, and you may need to try several before finding the most effective for you.
The starting dose for each form of alprostadil is as follows:
- injection – 1.25 to 2.5 micrograms (mcg)
- cream – 3mg/g
- MUSE – 250mcg
If you feel that the dose you are prescribed is too strong or not strong enough for you, it is important to let your doctor know. You must not change the dose yourself without consulting your doctor, who will advise you on what to do next.
If you are prescribed the alprostadil injection, your doctor will monitor you every 3 months to see how your body responds and if any dose adjustments are needed.
Side effects and precautions
Like all medications, alprostadil can cause side effects. However, the side effects can differ between the different forms. A very common side effect is pain in the penis, but this usually resolves quickly. However, if the pain is severe or lasts for a long time, you should speak to a doctor or go to A&E in an emergency
The side effects for each form of alprostadil are shown in the table below:
| Common | Uncommon | |
|---|---|---|
| Injection |
|
|
| Cream |
|
|
| Urethral suppository |
|
Because painful erections and anatomical changes in the penis are more likely when taking alprostadil, your doctor will monitor your treatment regularly. They will also monitor your blood pressure and discuss how well you think your treatment is going.
If you get an erection that lasts longer than 4 hours, you should go to A&E immediately to start urgent treatment.
Who should not take alprostadil?
Alprostadil is not suitable for everyone.
Do not take alprostadil if you:
- have been advised not to have sex
- have penile implants
- are taking any other erectile dysfunction medications
- have a condition that increases the chance of a prolonged erection
- have a severe curvature of the penis
Comparing alprostadil to other ED treatments
Alprostadil is not the only erectile dysfunction treatment available, and it’s usually offered when other medications are not suitable or have not worked. Most people find it easier and more comfortable to take oral tablets. The alternative erectile dysfunction medications offered by Superdrug Online Doctor are:
Phosphodiesterase type-5 (PDE-5) inhibitors
PDE-5 inhibitors are a class of medications that relax blood vessels by inhibiting (blocking) the PDE-5 enzyme. In doing so, they increase blood flow to the penis, helping you get and keep an erection that’s good enough for sex. They are mostly available in oral tablet form and are highly effective. At Superdrug Online Doctor, we can provide the following:
- Viagra – probably the most well-known ED treatment that contains the active ingredient sildenafil, and is 74% effective
- Viagra Connect – an over-the-counter version of Viagra that’s available in a standard 50 mg dose and is also available as a generic sildenafil version
- Hezkue spray – an oral sildenafil spray that is equally effective as Viagra, but has a flexible dosage and does not require you to take pills
- Cialis – the longest-lasting ED pill that can remain effective for up to 36 hours and is more than 80% effective, and available as generic tadalafil
- Cialis Together – an over-the-counter form of Cialis that does not require a prescription
- Vardenafil – a generic ED medication that is 80% effective and works similarly to Viagra
- Spedra – a branded version of avanafil that can work in as little as 15 minutes and is effective for up to 59% of people who use it
Other ED treatments
If PDE-5 inhibitors are ineffective for you or you would prefer not to take pills, there are some alternatives available, such as:
A topical gel that is applied directly to the head of the penis and can help 60% of people get an erection within 10 minutes. It works by stimulating blood flow to the penis using a unique warming and cooling effect and does not contain any active ingredients, so has fewer side effects.
Penis pumps are manually operated devices that increase blood flow to the penis to help you get an erection.
Alternatively, if you’re concerned about erectile dysfunction or would like to investigate the possible causes, you can request an at-home erectile dysfunction test kit. The test checks for several common potential underlying causes of ED and can help you get the most appropriate treatment.
FAQs
Is alprostadil available over the counter?
No, alprostadil is a prescription-only medication, which means you need a doctor’s approval before you can obtain it. If you are looking for an over-the-counter erectile dysfunction treatment, there are several available, including Viagra Connect, Cialis Together, and Eroxon Gel.
Can you get alprostadil on the NHS?
Yes, but only if you meet certain criteria. You will need to make an appointment with your GP to find out what treatments are available on the NHS for erectile dysfunction.
What is the average cost of alprostadil?
The cost of alprostadil depends on what form you buy (injection, suppository, or cream), whether the medication is branded or generic, and what dose you need. At Superdrug Online Doctor, we can provide Vitaros cream, whose active ingredient is alprostadil, from £64.00.
How long does it take to work?
Alprostadil generally takes between 5 and 30 minutes to work.
Is alprostadil better than Viagra?
Alprostadil and Viagra are different types of medication, making it difficult to compare. Oral medications, like Viagra, are often recommended as a first-line treatment for erectile dysfunction because they are easy to use and tend to have a lower-risk profile compared to injections. However, alprostadil may be suitable if oral medications have become ineffective or are not suitable for you.
Can you use alprostadil with other ED meds?
No, you should not combine alprostadil with other erectile dysfunction medications because this can increase the risk of serious side effects, including a prolonged erection that lasts for more than 4 hours.
Can you drink alcohol when using alprostadil?
Yes, you can drink alcohol while using alprostadil, as no interactions have been found between alcohol and alprostadil. However, alcohol can increase the chance of erectile dysfunction, so it is recommended that you limit or avoid alcohol to increase the effectiveness of the medication.
Brenda studied medicine at St Georges University of London and has most recently worked in John Radcliffe Oxford University Hospitals, covering acute and general medicine. Before her medical career, Brenda was a medical scientist in microbiology working in several NHS diagnostic laboratories across England. She has also completed her Masters in Public Health and MSc in Genomic Medicine. She is currently a GP registrar.
Last reviewed: 12 Sept 2025
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