What is Cialis?
Last week our Molecule Monday was the popular Viagra. This week our Molecule Monday is another erectile dysfunction treatment drug named Cialis (Tadalafil). Like Viagra, Cialis is a PDE5 inhibitor (inhibits the degradation of cGMP, increasing blood flow to the penis during sexual stimulation). The Cialis molecule was approved by the FDA in 2003, roughly 5 years after Viagra was. It was developed by ICOS, a small biotech firm in the US.