What are the potential side effects of Viagra Connect?
Possible side effects of Viagra Connect include:
Nausea
Vomiting
Back pain
Diarrhoea
Allergic rash
These side effects are usually mild and go away on their own. In rare cases, serious side effects can happen, such as:
Chest pain before, during or after sex
An erection that lasts longer than 4 hours, which can sometimes be painful
Sudden worsening or loss of vision
An allergic reaction, such as wheezing, dizziness, difficulty breathing or facial swelling
If you have any of these, get medical help straight away.
Warnings
Don't take Viagra Connect if you:
Don't have erectile dysfunction
Take any medicine containing nitrates
Have low blood pressure
Have a deformed penis
Are allergic to any of its ingredients
ED can also be a sign of other health conditions, such as high blood pressure, cardiovascular (heart and blood vessel) disease, diabetes and high cholesterol. Book a health check-up with your doctor within 6 months of starting Viagra Connect. This helps rule out a serious underlying condition as the cause of your ED.
For a full list of side effects, read the Viagra Connect patient information leaflet.
What are the potential side effects of Viagra Connect?
Possible side effects of Viagra Connect include:
Nausea
Vomiting
Back pain
Diarrhoea
Allergic rash
These side effects are usually mild and go away on their own. In rare cases, serious side effects can happen, such as:
Chest pain before, during or after sex
An erection that lasts longer than 4 hours, which can sometimes be painful
Sudden worsening or loss of vision
An allergic reaction, such as wheezing, dizziness, difficulty breathing or facial swelling
If you have any of these, get medical help straight away.
Warnings
Don't take Viagra Connect if you:
Don't have erectile dysfunction
Take any medicine containing nitrates
Have low blood pressure
Have a deformed penis
Are allergic to any of its ingredients
ED can also be a sign of other health conditions, such as high blood pressure, cardiovascular (heart and blood vessel) disease, diabetes and high cholesterol. Book a health check-up with your doctor within 6 months of starting Viagra Connect. This helps rule out a serious underlying condition as the cause of your ED.
For a full list of side effects, read the Viagra Connect patient information leaflet.
Viagra Connect frequently asked questions
Want to know more about Viagra Connect before you start using it? We've answered some frequently asked questions below.
How does Viagra Connect work?
Like Viagra, Viagra Connect lets more blood flow to the penis. It does this by relaxing the blood vessels in the penis, which helps you get and keep an erection during sex. When you're no longer aroused, the erection goes away. Viagra Connect and other medicines in the same group (known as PDE5 inhibitors) don't cure ED. They only work if you're sexually stimulated.
Is Viagra Connect the same as Viagra?
Viagra and Viagra Connect contain the same active ingredient, so they treat ED in the same way. The main difference is that Viagra Connect doesn't need a prescription.
How effective is Viagra Connect?
Studies have shown that Viagra Connect is effective in 74% of men with ED.
Why is it possible to get Viagra Connect without a prescription?
In November 2017, the MHRA decided to reclassify 50mg coated Sildenafil tablets as a pharmacy (P) medicine. This means you can get them without a prescription. P medicines can only be supplied after you've answered a series of health questions, to check they're suitable for you. It was also expected that making Viagra Connect more widely available would reduce Viagra sales from unlicensed online 'pharmacies'.
Is Viagra Connect suitable for me?
Viagra Connect is only for men over the age of 18 who have erectile dysfunction. Men with coronary artery disease, particularly those who take nitrates or nitroglycerine, should not take Viagra Connect, as it can cause a dangerous drop in blood pressure. If you take any other medicines regularly, talk to your doctor before taking Viagra Connect. Some medicines, like nitrates and alpha-blockers, can interact with Viagra Connect and lower your blood pressure.
How can I maximise the effectiveness of Viagra Connect?
Viagra Connect usually takes 30 to 60 minutes to start working. It won't give you an erection straight away, and it only works if you're sexually aroused. You and your partner should start foreplay about half an hour after you take Viagra Connect. It works for up to 4 hours, so your penis will stay responsive to sexual stimulation throughout that time.
Try to eat very little or nothing before taking Viagra Connect. You can take it with or without food. But if you take it after a high-fat meal, such as pizza or steak, it may take a little longer than usual to start working.
What other treatment options are available for ED besides Viagra Connect?
The most commonly prescribed medicines for erectile dysfunction belong to a group called PDE5 inhibitors. These are Levitra (Vardenafil), Sildenafil, Tadalafil and Spedra (Avanafil). They have been found to work for most men with ED, especially those with mild to moderate ED.
Our Clinical Authors
This page has been written by a registered UK pharmacist and reviewed by our clinical team to ensure it is accurate, clear and reflects current clinical guidance.
Last medically reviewed: 06 November 2026
Last updated: 06 November 2026