Tadalafil in Vidalista 40 works by acting on the blood vessels in different regions of the body. It acts by blocking the enzyme Phosphodiesterase (PDE5) which in turn prevents the breakdown of cGMP. This is responsible for the relaxation of blood vessels. When the drug acts on the blood vessels towards the pelvic region, more amount of blood flows through the dilated vessels. The blood vessels in the p*nis are in a relaxed state and hence more blood is pumped in penile tissues, leading to an erection. The erection is sustained for a reasonable time which supports s*xual intercourse. The effects of the drug are visible only when the person has proper s*xual stimulation prior to intercourse. The drug is excreted within 48 hours from the body.