Tadalista 40mg belongs to the class of drugs known as phosphodiesterase-5 (PDE5) inhibitors. Erections are caused by the accumulation of a large amount of blood in the organ. cGMP is responsible for erections. Tadalista 40mg is designed to act solely on cGMP and cause perfect erections. The recommended dosage of generic Tadalista 40 Professional is once a day. However, many practitioners prefer to prescribe this once-a-day dosage to help most patients achieve the desired results.