Tadfil 20 mg has been shown to be effective in improving erectile function in men with ED. It can help you achieve erections that are firm enough for satisfactory sexual intercourse. Tadfil 20 mg works by increasing blood flow to the penis during sexual stimulation. It inhibits the enzyme PDE5, which is responsible for regulating blood flow in the penile tissues. This improved blood flow helps men achieve and maintain an erection suitable for sexual activity. Common side effects of Tadfil 20 mg may include headache, indigestion, back pain, muscle aches, flushing, nasal congestion, and dizziness. These side effects are usually mild and temporary.