Fildena 100 mg is a prescription medication used to treat erectile dysfunction (ED), a common sexual health condition in men. The active ingredient in Fildena 100 mg is Sildenafil Citrate, which is also the active ingredient in Viagra, a well-known ED medication. Sildenafil Citrate works by increasing blood flow to the penis, which helps men achieve and maintain an erection when sexually aroused. You should take Fildena 100 mg approximately 30 minutes to 1 hour before sexual activity. It should be taken with a glass of water, and it can be taken with or without food.