Sildenafil is a medication used to treat Erectile Dysfunction (ED). It belongs to a group of medicines called phosphodiesterase type 5 (PDE 5) inhibitors. PDE 5 Inhibitors work by relaxing the blood vessels in the penis in response to sexual stimulation and allowing more blood to flow into the penis and help with getting and maintaining an erection. Sildenafil will only help you to get an erection if you are sexually stimulated.

Generic Sildenafil and Viagra are medically IDENTICAL and have the same active medicine (Sildenafil) and will work in the same way. The only difference is Viagra is considerably more expensive than generic Sildenafil.

Pfizer was the original manufacture for Sildenafil and they sold it under the brand name Viagra. Sildenafil is the active medicine which treats Erectile Dysfunction. It is usually known as the generic name so no matter whether you have the branded Viagra or the generic manufactured Sildenafil – they are exactly the same.

When a drug company discovers a new medicine, they take out a patent which means that no other company can make its newly discovered drug for a period of time. The company which discovered this new drug and has a patent on it will usually sell it under a brand name.