Fildena 100 mg works by inhibiting the enzyme phosphodiesterase type 5 (PDE5) in the body. This inhibition allows for increased levels of cyclic guanosine monophosphate (cGMP), a chemical that promotes relaxation of smooth muscles and vasodilation in the penile arteries. As a result, blood flow to the penis improves, facilitating the achievement and maintenance of an erection during sexual stimulation. Fildena 100 mg enhances the body's natural response to sexual arousal, enabling men with erectile dysfunction to achieve satisfactory erections for sexual intercourse. It's important to note that Fildena 100 mg does not cause spontaneous erections; sexual stimulation is still required for its effectiveness.