Fildena Double 200 is a medication used primarily for treating erectile dysfunction. Its active ingredient is Sildenafil Citrate, which is a potent phosphodiesterase type 5 (PDE5) inhibitor. Sildenafil works by relaxing the blood vessels in the penis, which helps increase blood flow and achieve an erection in response to sexual stimulation. It's important to use this medication under the guidance of a healthcare professional, as it has potential side effects and interactions with other medications.