Taking an erectile dysfunction medication like Viagra? It’s important to be aware that, like all prescription treatments, it can cause some unwanted symptoms. The good news is, the majority of the side effects from Viagra patients experience are mild and temporary. 

What is Viagra and how does it treat erectile dysfunction?

The active ingredient in Viagra is sildenafil, which belongs to a class of medications called phosphodiesterase type 5 inhibitors (PDE5 inhibitors). Its primary function is to help relax the blood vessels, allowing more blood to flow to the penis during sexual activity. This makes it easier to both maintain and achieve an erection.

One important aspect to remember is that Viagra only works in response to sexual stimulation — in other words, it’s essential to be aroused for the treatment to cause an erection.

The time it takes for Viagra to take effect can vary between individuals, but it usually starts between 30 minutes to an hour. Keep in mind that taking Viagra with a heavy meal might delay the time it takes to start working.

Who can use Viagra?

Viagra and other PDE5 inhibitors are prescribed to adults dealing with erectile dysfunction (ED), also known as impotence. This condition is characterised by difficulty in achieving or maintaining an erection suitable for sexual activity. Although Viagra is safe, approved by doctors and well-researched, there are some health facts you should be aware of before taking it.

Allergies
Don’t take Viagra if you’re allergic to sildenafil or any of its ingredients.

Health conditions
Certain health concerns like severe liver or heart conditions, such as a recent stroke or heart attack, and specific inherited eye diseases (for example, retinitis pigmentosa) can make Viagra unsafe. Also, if you have ever experienced vision loss due to non-arteritic anterior ischaemic optic neuropathy (NAION), it’s not recommended that you use this medication.

Check with a GP first if you have sickle cell anaemia, leukaemia, or multiple myeloma, a deformity of the penis or Peyronie’s Disease, heart problems or a history of stomach ulcers or bleeding issues, as these conditions can have risks of complications.

Other medications
Avoid Viagra if you’re taking nitrates, nitric oxide donors like amyl nitrite (“poppers”), riociguat, or any recreational drugs. Combining these can lead to a dangerous decrease in blood pressure, which can lead to dizziness, fainting, or even a heart attack.

Side effects of Viagra

Let’s talk about the side effects people are most likely to experience when taking Viagra. These effects impact between one in 10 and one in 100 people: headaches, feeling faint, nausea, upset stomach, nasal congestion, visual disturbances and hot flushes.

Less commonly, (only affecting between 1 in 100 and 1 in 10,000 people using Viagra), some experience side effects including: vomiting, indigestion, abdominal pain, rashes, eye irritation (pain, blurred vision, double vision, bloodshot eyes), tinnitus, vertigo, nose bleeds, increased heart rate, fainting, muscle ache, fatigue, chest pain, numbness, or hypersensitivity to pain, and blood in the urine.

How to minimise side effects of Viagra

The majority of common side effects are temporary and should not last for long after taking the pill. The side effects should also stop entirely when discontinuing the medication at any time. If side effects are prolonged, stop using the medication and seek medical attention.

Stand up slowly

To help lower the possibility of dizziness by standing up more gradually from a seated or laying position to avoid getting a head rush.

Limit alcohol intake
The intake of alcohol can influence the time Viagra takes to have an effect, and can also make it more difficult to achieve an erection.

Lower the dose
Discuss taking a lower dosage of Viagra with a clinical expert or doctor if side effects are intolerable.The outcome of the treatment will still help with getting an erection, but you should have less side effects on a lower dose.

Have it with food
Typically, Viagra is taken on an empty stomach, but taking it with a meal can help reduce any unwanted side effects, including an upset stomach and nausea. This may slightly reduce the efficiency of the drug or mean that it takes longer for the medication to kick in, but most people find a balance that works for them.

Take the medication correctly
Always follow the prescriber’s instructions on how to use it to reduce the risk of unwanted side effects. Viagra should be taken with water about one hour before sexual activity, and should only be taken once a day. The average dose to start with is 50mg, but it’s best to follow personalised medical advice from your prescriber. It’s important to adhere to the dosage prescribed  — taking more than the recommended amount can increase the likelihood and severity of side effects without improving effectiveness. If you accidentally take more than you should, contact a GP immediately or call 111.

Rare Viagra side effects

Although extremely rare, there have been cases where people have experienced severe side effects and reactions to Viagra, including:

• Heart attack or heart failure
• Severe allergic reactions (difficulty breathing, rash, swelling of the face, throat and tongue)
• Sudden drop in blood pressure
• Eye issues such as double vision, reduced sharpness, swelling, or seeing halos around lights
• Swelling inside the nose
• Sudden hearing loss or irritation

Some serious side effects require immediate medical attention:

• Allergic reactions: Symptoms include wheezing, difficulty breathing, shortness of breath, and swelling.
• Chest pain: Especially if it occurs during or after sex. Sit in a semi-sitting position and relax, but do not take nitrates.
• Prolonged erections: If an erection lasts more than 4 hours, seek medical help immediately.
• Vision problems: Abnormal vision, such as sudden decrease or loss of vision.
• Skin reactions and seizures: Severe skin reactions or seizures also need urgent attention.

If you have any questions or experience any side effects or adverse reactions not listed, contact your doctor, pharmacist, or nurse. Reporting side effects helps improve the safety of medications.

For more detailed information, always refer to the official leaflet or consult with healthcare professionals. Your health and safety are paramount when considering treatments like Viagra.

What to do if Viagra doesn’t work

If you find that Viagra isn’t helping you achieve an erection or if your erection doesn’t last long enough for sexual intercourse, it’s essential to speak with a clinical expert of your GP. They can provide guidance and adjust your treatment plan if necessary.

Starting an erectile dysfunction treatment

Viagra can significantly improve the quality of life for many people, but it’s essential to use it responsibly and under medical guidance. 

Find out what treatment is suitable for you on our website.