Tadacip 20 mg is a medication used to treat erectile dysfunction (ED) in men. It contains Tadalafil as its active ingredient, which is a phosphodiesterase type 5 (PDE5) inhibitor. Tadalafil works by inhibiting the enzyme PDE5, which increases levels of cyclic guanosine monophosphate (cGMP) in the blood vessels of the penis. This leads to relaxation of smooth muscle and increased blood flow, which helps achieve and maintain an erection in response to sexual stimulation.