Insufficient blood flow in the penis is the root cause of Erectile Dysfunction. Tadalafil is the medicine's active ingredient which inhibits the Phosphodiesterase (PDE5) enzyme. These enzymes break down cyclic Guanosine Monophosphate (cGMP). Vidalista suppresses PDE5, resulting in maintained levels of cGMP and increased penile blood flow, which is necessary for maintaining an erection. However, this medicine only works when the person is sexually stimulated.