Vilitra 40 should be taken at least 30 minutes before your planned s*xual activity because the starting period of vardenafil is around 10 to 30 minutes. Once the medication is active in your system, it remains effective for up to 5 hours. If you are s*xually stimulated during these hours, you are sure to have successful erections. A single dose of Vilitra 20 mg should be taken within 24 hours to avoid the risk of overdose.