Under the brand name Tadarise, the medication tadalafil is used to treat erectile dysfunction (ED) in men. Tadalafil increases blood flow to the penis during sexual stimulation, which helps people achieve and maintain an erection. Tadalafil is an inhibitor of phosphodiesterase type 5 (PDE5). Mechanism of Action: Tadalafil functions by inhibiting the PDE5 enzyme from degrading cyclic guanosine monophosphate (cGMP). Tadarise Reviews smooth muscle cells in the penile blood arteries relax in response to higher amounts of cGMP, which enhances blood flow and promotes erection.