Kamagra contains the active ingredient sildenafil, which works by inhibiting the enzyme phosphodiesterase type 5 (PDE5). Kamagra inhibition increases levels of cyclic guanosine monophosphate (cGMP), leading to relaxation of the smooth muscles in the blood vessels of the penis. As a result, blood flow to the area increases, facilitating an erection when sexual stimulation occurs. It's primarily used to treat erectile dysfunction. However, it's important to use it under medical supervision, as there can be side effects and interactions with other medications.