·Fildena 100 is an online medication used to treat erectile dysfunction (ED). ED is a condition where a man's penile area fails to become firm enough for sexual activity or maintain an erection. Fildena 100 mg works by increasing blood flow to the penile area, which helps in achieving and sustaining an erection without any physical impact. However, it is important to note that taking Fildena may lead to common side effects such as headaches, indigestion, and muscle pain.