Fildena 50 (Sildenafil Citrate) is also known as the "purple pill" because it helps to reduce sexual impotence in men, increases blood flow to the nasal, and helps men maintain a longer erection. Sildenafil and Fildena Salt work together to increase the CGMP (Cyclic Guanosine Monophosphate) level responsible for muscle relaxation and leads to increased blood flow to the penis.