Viagra can cause changes in blood pressure for some men, and both high and low blood pressure are listed as uncommon side effects of taking Viagra.

Studies show that Viagra does drop blood pressure in men who take it, whether they already have blood pressure problems or not. This drop is considered to be ‘clinically insignificant’, which means it’s not going to cause health problems for most men. This effect Viagra has on blood pressure is not surprising since it was discovered by accident when scientists were looking for new blood pressure treatments. This change in blood pressure is related to how Viagra works and is part of the reason why Viagra makes it easier to get erections.

Most men find their side effects go away after 1 hour, and after 12 hours almost all side effects go away. The table below shows what percentage of men still have side effects after a certain amount of time after taking a dose of Viagra.

Looking at the long-term effects of Sildenafil, research shows that the number of men stopping treatment because of side effects remains very low – less than 1%. Men appear to be able to take Sildenafil long term without serious risk to their health, and without an increased chance of getting side effects.

Plus, evidence shows that men who take Sildenafil long term still find their treatment effective and don’t become resistant to it. This means that it’s safe to take Viagra for as long as you need it.

There’s a small increase in your chance of getting side effects as the dose of Viagra goes up. Still, there’s only a less than 2% chance of side effects across all doses.

This table shows the percentage of men who get certain side effects from Viagra, based on the dose they take. This shows that of the small percentage of men who get side effects, 16% of them will get a headache when taking 25mg of Viagra.

The side effects of Viagra and over the counter Viagra Connect are the same. This is because they share the same active ingredient, sildenafil citrate.

This is also the case with sildenafil, the generic version of Viagra, which also has exactly the same active ingredient and dosages as Viagra, the possible side effects. And your chance of getting them, will be the same.

But, since different manufacturers put slightly different ingredients in their tablets, you could see some difference in side effects between Viagra and sildenafil from different companies. For example, some manufacturers use lactose in their tablets and some don’t, which might cause a reaction for people with lactose intolerance.

There isn’t a lot of difference in the side effects experienced by older men compared to younger men. Research shows even most men over 70 can tolerate Viagra treatment without any serious problems.

As you get older, your chance of getting other health conditions that could make Viagra unsafe does go up, so some older men may need to take lower doses of Viagra. Also as you get older your body may get less efficient at removing Viagra from your system, so side effects may last a little longer than they would for younger men.

Alcohol doesn’t have a serious reaction with Viagra so you can drink in moderation and use Viagra safely. But, alcohol does make it more likely that you will get side effects from Viagra. Alcohol also makes it harder for you to get and keep erections, so drinking alcohol can make Viagra less effective.

Does Viagra give women side effects?

Studies on women using Viagra show that they get similar side effects to men taking Viagra, and don’t get any extra serious side effects. One instance of female genital bleeding was recorded, similar to the rare side effect of penile bleeding in men.

Even if some research suggests Viagra might be able to help with female sexual disorders, there isn’t enough evidence to support treatment. Because of this, and the risk of side effects that comes with Viagra, doctors can’t prescribe Viagra to women with sexual disorders.

Since women in the UK can’t get approved for Viagra treatment, it means they can’t be sure it’s safe for them to take it. Even if many women would only get mild side effects, if a doctor hasn’t made sure it’s safe, taking Viagra could come with a risk of serious or even life-threatening side effects.

See our page on Viagra for Women for more information.

Does fake/herbal Viagra cause side effects?

There’s a wide range of different products marketed as a herbal alternative to Viagra, so it’s hard to say exactly what side effects they might cause.

Many of these kinds of products aren’t properly regulated, and it’s hard to be certain of what ingredients are in them or how they are made. This means that they could have ingredients that cause side effects, possibly even serious ones. Some of these products may also contain unsafe amounts of actual medication, or combinations of medications, which could put you at risk of serious side effects.

Rather than put your health and your wallet at risk with potentially ineffective and unsafe products, it’s better to get authentic treatment, either online or from your GP or pharmacist.

How to avoid them

The best way to avoid getting side effects from Viagra is to take your medication as your doctor suggests. The tips below may also help you keep the risk low, and get the most out of your treatment:

• Be as accurate as possible with the information you give your doctor when getting Viagra treatment
• Read the patient information leaflet that comes with your Viagra
• Only take one tablet every 24 hours
• Don’t take Viagra with other erectile dysfunction medication
• Don’t drink alcohol
• Avoid grapefruit juice
• Avoid drug use, particularly amyl nitrates (poppers)

Taking the lower 25mg dose of Viagra will also give you a lower risk of side effects but it also has less chance of working. We recommend only moving down to 25mg with the help of a doctor once you’ve already tried 50mg.

How to get rid of them

Since most men find their side effects go away after just one hour, you might not need to do anything. If your side effects last for a long time, or happen every time you take Viagra, you should get in touch with a doctor. They’ll be able to make sure that it’s still safe for you to take Viagra, or whether there’s something else causing these side effects.

To stop side effects coming back next time you use Viagra, you could:

• Follow the advice above on how to avoid side effects
• Switch to a lower dosage with the help of a doctor
• Switch to a different erectile dysfunction treatment

Viagra is a safe and effective medication for most men. Less than 2% of men get side effects from Viagra and most people who do get side effects don’t get serious ones. As long as a doctor has approved treatment for you, you can be sure it’s safe for you to use.

Viagra can react with other medications but as long as you’ve told your doctor what medications you’re taking and they still approve treatment, it shouldn’t be a problem. Tell your doctor if you are taking any of the following:

• nitrates
• nitric oxide donors (“poppers”)
• protease inhibitors (used to treat HIV)
• alpha-blocker therapy
• riociguat used for pulmonary hypertension