Zudena 100 mg tablet, which contains the active ingredient udenafil, is used primarily to treat erectile dysfunction (ED) in men. It works by increasing blood flow to the penis during sexual stimulation, helping men achieve and maintain an erection. It can help achieve and sustain an erection firm enough for sexual activity. Many men find that it improves their overall sexual performance and confidence. It's important to use it under the guidance of a healthcare provider, as it may interact with other medications or have contraindications for certain health conditions.