Most men nowadays suffer from erectile dysfunction, impotence, or premature ejaculation, which prevents them from performing adequately in bed. Levitra 20mg might help you renew your intimate relationships with your companion. Levitra 20mg is an effective drug for treating erectile dysfunction, impotence, and premature ejaculation in men. This medication takes 30–60 minutes to take effect and can last up to 4-5 hours. However, you should take this medication exactly as prescribed by your doctor.