Malegra 25 mg is a medication used to treat erectile dysfunction (ED). It contains sildenafil citrate, a phosphodiesterase type 5 (PDE5) inhibitor, which helps improve blood flow to the penis and facilitates the ability to achieve and maintain an erection. This medication works by inhibiting the PDE5 enzyme, which breaks down cyclic GMP. Increased levels of cyclic GMP result in the relaxation of smooth muscle and dilation of blood vessels in the penis, leading to improved erectile function.