Also known as

• sildenafil
• sildenafil citrate

Very similar drugs made by different companies include:

• Cialis (aka tadalafil)
• Levitra (aka vardenafil).

‘Generic Viagra/Cialis’ means an almost identical version of the drug but one that's not sold under the well-known brand names. A common generic version is sold under the name Kamagra.

‘Herbal viagra’ has no relation to the drugs mentioned here. For more about this see lower down this page.

What is Viagra?

First approved for sale in 1998, Viagra is a prescription drug for treating erectile dysfunction (impotence). It is also widely available over the internet or from drug dealers. It's sold as blue diamond-shaped pills, with the maker's name (Pfizer) on one side and the dose on the other: 25, 50, 100 (milligrams).

Rival companies have since marketed similar drugs that work the same way, such as Cialis (yellow almond-shaped pills) and Levitra (orange pills).

Herbal viagra or cialis is marketed as a ‘natural’ alternative to the drug of the same name but does not contain the active ingredient (such as sildenafil), has no links to the makers of these brand name drugs and is not subject to the same strict testing and quality control as prescription drugs.

Herbal viagra may contain substances that relax blood vessels, and so increase blood flow, but these won't be effective specifically in the penis and may cause low blood pressure, depriving body organs of the blood supply they need. These ‘natural’ products may not be safe and might interact with other drugs.

What's the attraction?

For men with genuine erection difficulties, Viagra and its rivals offer a quick fix solution that is effective for most (but not all) men. It is also far more acceptable than earlier treatments, such as injections into the penis, penis implants, lengthy sexual counselling and impotence therapies.

These drugs are used by men to boost their sexual performance, including young men with no medical need for help. The drugs are also used to counteract recreational drugs that cause loss of hard-ons.

By increasing blood flow into the penis, Viagra and similar drugs help men to get erections and make erections harder and longer lasting. During the time the drug is in a man's body, it can increase how often he can get hard and come.

Viagra and sex

These drugs are not aphrodisiacs. They don't make you horny or cause instant erections, although they can boost sexual confidence. They only start to work after a man has become sexually aroused.

With these drugs some men report erections that are harder but with less sensation, and coming is more difficult. They can allow men to get another hard-on in a shorter time after they've come. For some the effects last a few days.