Viagra (Sildenafil)

Viagra is a medication used to treat erectile dysfunction (sometimes called impotence) in adult men. It contains the active ingredient sildenafil. It’s taken once a day, usually at least 4 hours before sex.

Viagra is for men 18 or older with symptoms of erectile dysfunction. It’s not meant for use in women. It’s also not right for everyone, so you might not be able to take it if you have certain health conditions or you’re already taking certain other medications.

Viagra works by helping to relax the blood vessels in your penis, which lets blood to flow in more easily when you’re sexually excited and can make erections easier to get. Viagra shouldn’t make you get an erection on its own: you need to be sexually aroused for Viagra to work.

Viagra usually begins to work between 30 minutes to 1 hour after taking it. But it can take up to 4 hours to have its full effect.

It will last for different amounts of time for different people, but it can have an effect for up to 5 hours. Most men will find that it will start to wear off 2 to 3 hours after first taking it.

Remember that taking Viagra alone will not cause an erection. Viagra must be taken with some form of sexual stimulation (things that look, feel, or are in some way sexually appealing to you) in order for an erection to occur.

Also consider that how well Viagra works, or how long it lasts for, can depend on a number of extra things including:

• your age
• diet
• your general health
• whether you’ve drunk alcohol
• the dose of Viagra you’ve taken
• any other medication you might be using

When taking Viagra, you should not get an erection that lasts longer than 4 hours. If this happens, it may be a sign of priapism and you should get medical help right away.

Viagra works for about 74% of the men who try it.

Most men experience a stronger and longer-lasting erection when using Viagra as recommended. This means avoiding alcohol and heavy meals before you use it. Viagra can also work better if you combine it with lifestyle changes, or devices like penis pumps or rings.

Viagra may be right for you if you’re a man over 18 years old and you regularly can’t get or keep erections.

Viagra may not be right for some men. Don’t take Viagra if you:

• have had an allergic reaction to sildenafil (Viagra) or any other medications in the past
• are taking medications for chest pain called ‘nitrates’
• have any serious heart, kidney, or liver problems
• have recently had a stroke or a heart attack
• have low blood pressure
• have a rare inherited eye disease, like retinitis pigmentosa

Also, you should check with your doctor before taking Viagra if you:

• have sickle cell anaemia (an abnormality of red blood cells), leukaemia (cancer of blood cells), or multiple myeloma (cancer of bone marrow)
• have an irregular penis shape or Peyronie's disease (a curved penis)
• have a heart problem
• have a stomach ulcer or a bleeding problem like haemophilia

If you’re using Viagra for the first time, as long as you don’t get any side effects, you should usually try the same dose of Viagra up to 4 times before thinking about changing your dose or treatment.

• 50 mg: you are likely to be given the 50 mg dose if this is your first time using Viagra, because it’s the standard starting dose recommended for most men
• 25 mg: this dose is usually given to men who tried the 50 mg first, got the effect they wanted, but got side effects as well
• 100 mg: your doctor would recommend this dose if you didn’t get the results you wanted after taking the 50 mg, but only as long as you also didn’t have side effects.

You should never take more than one tablet of Viagra a day. If you accidentally overdose, get medical help right away.

Taking alcohol before using Viagra can make it more difficult for you to get an erection. To get the most out of Viagra, avoid drinking alcohol before taking Viagra

Recreational drugs like poppers (amyl nitrite), cocaine, and ecstasy can cause damage to your heart, and this risk is higher if you take them with Viagra.

Viagra can react with some medications. You shouldn’t take Viagra if you are taking:

• alpha-blockers for high blood pressure
• other erectile dysfunction medications
• protease inhibitors for HIV treatment (e.g Ritonavir or Indinavir)
• Ketoconazole or Itraconazole antifungal medicines
• medicines for treatment of arrhythmia (irregular heart beat), like Quinidine, Procainamide, Amiodarone, or Sotalol
• Erythromycin, Clarithromycin, or macrolide antibiotics

If your first dose of Viagra doesn’t work and you don’t get side effects, try using it on up to 4 different days before thinking about next steps. If you still don’t get the results you want, and you didn’t have serious side effects, your doctor might suggest a higher dose for you.

If taking a higher dosage of Viagra still doesn’t work, you might want to think about alternative treatments for erectile dysfunction.

Viagra is part of a family of medications called PDE-5 inhibitors. The other medications in this family that are similar to Viagra include:

• Sildenafil
• Viagra Connect
• Cialis
• Cialis Daily
• Tadalafil
• Levitra
• Spedra

There are also other alternatives to Viagra which don’t involve taking medication. These include:

• Counselling or therapy
• Vacuum erection devices (penis pumps)
• Penile implants

You can visit our page for more details on alternatives to Viagra for erectile dysfunction.

Very rarely, some people have had very serious side effects when using Viagra. You should stop taking Viagra and get emergency medical help if you get:

• chest pains during or after sex
• prolonged and sometimes painful erections lasting more than 4 hours (priapism)
• a sudden decrease or loss of vision
• seizures
• symptoms of an allergic reaction such as tightness in your chest, trouble talking or breathing, a red and swollen skin rash, or swelling in your throat, face, lips or mouth

You can check the fact sheet on the right for a list of common side effects of taking Viagra.