What is Fildena? In simple words, Fildena is a drug that men with erectile dysfunction get from their doctor. It has sildenafil citrate in it, which is the same active ingredient that is in Viagra. Fildena is made by Fortune Healthcare in India. Because of its unique color, it is often called the “purple pill.” Sildenafil citrate, which is what Fildena is mostly made of, stops PDE5 from working. In other words, it stops the enzyme phosphodiesterase type 5 (PDE5) from doing its job, which is to cut off blood flow to parts of the body like the penis. Fildena, including versions like Fildena CT 50, helps boost blood flow by blocking PDE5. This makes erections stronger and last longer when sexually stimulated.