The desire to have sex is common among all living things animals and plants. In general use in many languages, the term sex is often used to mean sexual activity. In order to have a satisfying sexual experience both male and female must be sexually healthy. However, with the advancement of medical science, it is proven that male is more to blame than female in an unsatisfying sex.

Erectile dysfunction (E D) is a common ailment in most adult males. Erectile Dysfunction is the inability of the penis to become rigid (hard), or to stay rigid long enough to finish having sex.

The success of Viagra as a treatment for ED, in spite of its price being beyond the reach of ordinary folks, is a proof in itself. . An estimated 30 million men in the US and 175 million worldwide suffer from erectile dysfunction, and only a fraction is currently using Viagra. The current Viagra market of around $1.5bn a year could rise to total impotence drug sales of around $6bn over the next eight years, split between Viagra, Cialis, Levitra and other second-generation treatments.

A strong contender which could displace Viagra from its number one position is Cialis. As with Viagra, Cialis is likely to be used as a performance enhancer, rather than just as treatment for an ailment. All these impotence drugs block an enzyme called phosphodiesterase 5 (PDE-5), which relaxes smooth some kinds of muscle cells and allows increased blood flow into the penis.

Cialis starts working faster than Viagra, sometimes in 16 minutes, and lasts 24 hours or more. In contrast, Viagra usually works for only four hours after an hour's delay.

As with Viagra, 80% of men with erectile function are able to achieve an erection when on Cialis use and three out of four are able to achieve sexual intercourse. But in one Cialis study, 59% of previously impotent men were still able to have sex 36 hours after taking it. The reason is that the body takes four times as long to get rid of Cialis than to eliminate Viagra.

Like any other drug Cialis too is not without its side effects. Cialis can cause your blood pressure to drop suddenly to an unsafe level if it is taken with certain other medicines. You could get dizzy, faint, or have a heart attack or stroke. If you are over 65 years of age, you may be more likely to experience side effects from Cialis. Your doctor may prescribe a lower dose of this medication.