Most people look for the generic name when it comes to purchasing medicines. Aside from the fact that generics have the same composition with the brand name; it also has a cheaper price. The generic name for Cialis is Tadalafil, which is a PDE5 inhibitor that is used to treat erectile dysfunction, which was then named Cialis. It was ICOS who initially developed Tadalafil.  It was then further developed and opened to the worldwide market by the joint venture of ICOS Corporation and Eli Lilly Company.

It was Glaxo Wellcome, which is now known as GlaxoSmithKline who discovered Cialis in  August 1991 together with the  partnership of  biotechnology company ICOS Corporation. In 1993, ICOS began to study phosphodiesterase type5 (PDE5) enzyme inhibitor, a compound of IC351.  They discovered the potential usefulness of the compound for treating Erectile Dysfunction.   The patent for compound IC351 was received by ICOS in 1994.  Clinical studies were then initiated studying men with Erectile Dysfunctions that was then approved by FDA (Food and Drugs Administration) on November 21, 2003. This FDA approval aided ICOS to progress to Phase 3 clinical studies and trials.

It was in 1998 that ICOS Corporation formed a joint venture with Eli Lilly Company that was formed to be Lilly ICOS, LLC with an aim to further develop and commercialize Tadalafil as a discovered treatment for men with Erectile dysfunctions.  Lilly ICOS, LLC filed a New Drug Application 2 years after for the compound IC351 with the FDA, having Cialis as the brand name and Tadalafil as the generic name. They continued to conduct clinical studies observing thousands of men with erectile Dysfunctions that will prove the efficiency of Tadalafil. Food and Drugs Administration (FDA) approved the use of Tadafil, generic name for Cialis, one year after. Now, Eli Lilly and Company continue to mark the worldwide market with the most effective Cialis that proudly to stand out in the market.