Vidalista 10 mg contains tadalafil, a PDE-5 inhibitor used for erectile dysfunction. It improves penile blood flow like this: Sexual stimulation causes your body to release nitric oxide in penile tissue. Nitric oxide increases cGMP, a chemical signal that relaxes the smooth muscle in the penis. Vidalista 10 mg allows the penile blood vessels to dilate and fill with blood, producing an erection. Tadalafil blocks PDE-5, the enzyme that breaks down cGMP. This helps the blood-flow signal last longer and makes it easier to achieve and maintain an erection. Tadalafil doesn't create an erection by itself—sexual stimulation is still needed. Its effect can last considerably longer than sildenafil, with tadalafil's effects potentially lasting up to about 36 hours. Also, tadalafil can lower blood pressure, so it must not be combined with nitrate medicines such as nitroglycerin.