Take one tablet one hour before you plan to have sex. Viagra pills should be swallowed whole and taken with water. It should stay active in the body for up to five hours, so you don’t need to rush having sex.

You shouldn’t take more than one Viagra tablet in any 24 hour period. If you take one and find it doesn’t work as well as you would like it to, speak to your doctor.

Viagra isn’t an aphrodisiac. You’ll need to be sexually stimulated for it to work.

Tell your doctor if you get any side effects. It’s rare, but some men who take ED medication get an erection that won’t go down. If this happens, and you have an erection that doesn’t go away after four hours, go straight to your nearest emergency room for medical advice.

It can take longer for Viagra to work if you take it after eating a large meal. Drinking grapefruit juice can increase the metabolism of some medicines (including Viagra) and make the effects of them stronger, so you should avoid this when taking Viagra.

Viagra and alcohol aren’t thought to interact with each other. But alcohol is known to have a negative effect on erectile potency. So you should avoid drinking excessive amounts of alcohol if you have ED.

Your doctor will help you settle on the right dose of Viagra.

50mg tends to be the best option for men taking Viagra for the first time. If someone finds this works well, but gets mild side effects, a doctor may advise reducing the dose to 25mg.

100mg is recommended when someone takes the 50mg dose but finds it doesn’t work well enough.

It’s important not to try and change your dose yourself. If you get any side effects when taking Viagra, or if it doesn’t feel like the dose you’re on is strong enough, let your doctor know. They can prescribe a dose (or drug) that’s likely to be better for you.

For the majority of men who take Viagra it works either the first or second time. Those who find 25mg or 50mg isn’t quite strong enough can often benefit from being prescribed a higher dose.

The effectiveness of different Viagra doses has been assessed in clinical trials. These found that:

• 62% of men taking the 25mg dose found it improved erections
• 74% of men taking the 50mg dose had improved erections
• and 82% of men using the 100mg dose reported improved erections.

Headache is the side effect reported most commonly in men taking Viagra (affecting more than 1 in 10 users), followed by nausea, hot facial flushing, stuffy nose, dizziness or mild visual disturbances (all common, affecting less than 1 in 10 users).

Following the instructions carefully can help to reduce the likelihood of these.

Mild side effects will sometimes only occur the first couple of times you take a medicine. You can do things yourself to alleviate some mild side effects, like takin acetaminophen for a headache and making sure you drink plenty of water. If you get a stuffy nose, taking a lozenge may help.

If you get side effects that are more uncomfortable or persist, it may be better to speak to your doctor about changing your dose.

Let your doctor know if you get any side effects that cause you concern.

Seek medical attention urgently or go to the emergency room if you get: any signs of an allergic reaction, like swelling around the face or throat, or hives; pain or tightness in the chest; loss of hearing or vision problems; an erection that won’t go away for four hours or more; or any other side effects that feel serious.

Yes. For men concerned about how much Viagra costs, Sildenafil is the same drug and much cheaper a lot of the time. It’s a generic medicine so it isn’t always made by Pfizer, but it should work just as well.

Sildenafil or ‘Generic Viagra’ was released in 2013, after the 15 year patent on Viagra expired.

The generic does the same job as the branded treatment, though the tablets may look different and come in different packaging. So if you’re looking for ED treatment and thinking about whether to buy Viagra, you may want to consider Sildenafil. For many men it’s a more affordable option.

Let your doctor know. They can discuss different doses with you to see if these work better, or recommend a different drug.

They’re similar drugs with minor differences, so it depends on your preference. Cialis is a tablet that lasts for up to 36 hours. There’s also another version you can take every day.

Viagra only lasts for up to five hours, but this may be enough for some men. Per tablet, it’s cheaper than the weekend pill version of Cialis. Some men may also find that a specific brand just works better for them.

No. There is a treatment called Addyi which is sometimes called ‘female Viagra’ but in truth, it has very little in common with Sildenafil. It’s a treatment for HSDD (hypoactive sexual desire disorder) or low libido. Viagra for men doesn’t have the equivalent effect: it treats erectile dysfunction, but not low sex drive.

Viagra pills are for men only, and aren’t safe (or at all beneficial) for use by women.