Cialis is approved for the treatment of men who experience difficulty having and maintaining an erection (impotence).

Cialis works by enhancing the effects of one of the chemicals the body normally releases into the penis during sexual arousal. This allows an increase of blood flow into the penis. An erection is the result of an increase in blood flow into certain internal areas of the penis.

Cialis is different from other currently approved products for ED in that it stays in the body longer. However, there were no studies that directly compared the clinical efficacy and safety of Cialis to other products.

Cialis is taken orally before sexual activity, not more than once daily.

Cialis may be taken with or without food. In some patients, the dose strength and maximum frequency of use may be adjusted.