Suhagra 50 mg works by inhibiting the enzyme phosphodiesterase type 5 (PDE5), which is responsible for the breakdown of cyclic guanosine monophosphate (cGMP). By blocking PDE5, Suhagra 50 mg increases the levels of cGMP, leading to relaxation of smooth muscle in the penile arteries and increased blood flow. This helps in achieving and sustaining an erection in response to sexual stimulation.