Fildena 100 purple pill is a medication that contains sildenafil, primarily used to treat erectile dysfunction (ED) in men. Fildena 100 works by inhibiting the enzyme phosphodiesterase type 5 (PDE5). This enzyme breaks down a substance called cyclic guanosine monophosphate (cGMP), which is essential for maintaining an erection. Fildena 100 is primarily prescribed for men who have difficulty achieving or maintaining an erection sufficient for sexual intercourse. It is typically taken about 30 minutes to 1 hour before sexual activity.