Viagra in the UK: how it works, how long it lasts and buying it safely

What is Viagra?

Viagra is the brand name for sildenafil, a medicine used to treat erectile dysfunction, which simply means difficulty getting or keeping an erection firm enough for sex. It's very common, especially as men get older, and it's nothing to be embarrassed about. Doctors and pharmacists talk about it every day.

Sildenafil is sold under the Viagra name and also as cheaper unbranded versions, which contain the same active ingredient. In the UK you can get it on prescription from a GP, or buy a version called Viagra Connect from a pharmacy after a short chat with a pharmacist.

This guide is general information, not medical advice. Everyone's health is different, so speak to a pharmacist or your GP about whether sildenafil is right for you.

How does Viagra work?

An erection happens when blood flows into the penis and stays there. Sildenafil works by relaxing the blood vessels in the penis so more blood can flow in when you're aroused. It belongs to a group of medicines called PDE5 inhibitors.

The important thing to know is that it doesn't create desire or cause an erection on its own. You still need to feel aroused for it to work. It also isn't an aphrodisiac and won't change how you feel about a partner. Think of it as removing a physical obstacle rather than flicking a switch.

How long does Viagra take to work, and how long does it last?

Viagra usually takes about 30 to 60 minutes to start working, so most people take it roughly an hour before they expect to have sex. It can take longer after a large or fatty meal, because food slows down how quickly the medicine is absorbed. Taking it on a lighter stomach often helps it work sooner.

Once it's working, the effect lasts for around 4 hours. That doesn't mean a 4 hour erection. It means that during that window you're more likely to get an erection when you're aroused, and it should go down normally afterwards.

Don't take more than one dose in 24 hours, and don't take extra if the first dose seems slow. If it doesn't help after a few tries on different occasions, a pharmacist or GP can talk through other options.

Can you buy Viagra over the counter in the UK?

Yes. Since 2018, Viagra Connect 50mg has been available in UK pharmacies without a prescription for men aged 18 and over. You don't just pick it off the shelf, though. A pharmacist will ask you a few private questions about your health and any medicines you take, to check it's safe for you. You can usually have this chat in a private consultation room.

You can also buy it from online pharmacies, which will ask you to fill in a health questionnaire instead. Only use online pharmacies registered with the General Pharmaceutical Council (GPhC), and check the registration on the GPhC website. Your GP can also prescribe sildenafil, and in some cases other treatments, if it suits you better.

Is Viagra safe? Side effects and who should check first

For most men, sildenafil is a safe and well tested medicine when used as directed. Common side effects include headaches, a flushed face, a blocked nose, indigestion and feeling dizzy. These are usually mild and wear off as the medicine does.

Never take Viagra with medicines called nitrates, which are often prescribed for chest pain, or with recreational poppers (amyl nitrite and similar). Together they can cause a sudden and dangerous drop in blood pressure. If you have heart problems, low or high blood pressure, or you take any blood pressure medicines, talk to a pharmacist or GP before using it.

Get urgent medical help if an erection lasts longer than 4 hours, if you have chest pain, or if you notice a sudden change in your eyesight or hearing. Call 999 in an emergency, or 111 for urgent advice.

Can women take Viagra? And how to avoid fakes

Viagra is not licensed for women in the UK, and Viagra Connect is only sold to men. There has been research into sildenafil for women, but the results have been mixed. If you're a woman worried about low desire or arousal, a GP or a sexual health clinic is the best place to start.

Be wary of cheap Viagra from unregulated websites, social media sellers or anyone offering it without health questions. Counterfeit pills are common and may contain the wrong dose or other substances altogether. The same goes for so called herbal alternatives sold in some adult shops or online, which can contain hidden medicines. Our guide to spotting fakes and scams covers more warning signs.

And whatever helps you feel confident, good sex is always about mutual consent between adults. Our guide to consent and boundaries is worth a read too.