If Vidalista CT 20 contains tadalafil, it affects blood flow by inhibiting PDE5, an enzyme that breaks down cGMP. This allows cGMP levels to remain higher during ***** stimulation, relaxing the smooth muscle in the penile blood vessels and increasing blood flow into the *****. In practical terms: ***** stimulation is still required for an erection; tadalafil does not cause an automatic erection. The increased blood flow can help a man achieve and maintain an erection suitable for ***** activity. Tadalafil can also cause some blood-vessel relaxation elsewhere in the body, which can contribute to effects such as lowered blood pressure. It should not be combined with nitrate medicines, because excessive blood-pressure lowering can occur. The specific Vidalista CT brand/formulation should be verified from its packaging and regulatory information; the mechanism above describes tadalafil itself.