Megalis 20 mg is a medication used for the treatment of erectile dysfunction (ED) in men. It contains the active ingredient tadalafil, which is a phosphodiesterase type 5 (PDE5) inhibitor. Tadalafil helps improve blood flow to the penis during sexual stimulation, facilitating the ability to achieve and maintain an erection. Tadalafil, the active ingredient in Megalis 20 mg, works by inhibiting the enzyme phosphodiesterase type 5 (PDE5). This inhibition increases the levels of cyclic guanosine monophosphate (cGMP), leading to smooth muscle relaxation in the blood vessels of the penis. This relaxation allows for increased blood flow, facilitating an erection. Megalis 20 mg indicates the strength of the medication. It is a moderate dose of tadalafil. Dosage recommendations should be followed as prescribed by a healthcare provider.