Vardenafil is a prescription medication used to treat erectile dysfunction (ED). By taking Vardenafil, you may Improve your ability to achieve and maintain an erection, Feel more confident in your sexual performance, Experience greater satisfaction with the firmness of your erections. Like all medications, ED treatments can cause some side effects. The most common ones are: headaches, muscle aches, back pain, flushing, low blood pressure, abnormal vision and indigestion. Please speak with your GP or pharmacist if you experience any of these side effects for a prolonged period of time.