Contact your medical provider if you experience any side effects during treatment. An erection results from an increase in blood flow to the penis. Those with a history of blood pressure or heart issues, hormonal imbalances, mental health issues, and diabetes should consult their doctor before trying PDE5 inhibitors. Follow-up support: Make sure you can get the help you need if questions or concerns arise after ordering. Read our editorial process. This increase in blood flow results in a firmer, longer-lasting erection.mg, 5 mg, 10 mg, 20 mg: 5 mg, 10 mg, 20 mg: 50 mg, mg, mg: Usual dose you take: 50 mg: 10 mg (when used as needed); mg (when used daily) 10 mg; 5 mg (for men 65 years old and. The typical starting dose is 10 mg by mouth about 1 hour before sexual activity. Your provider will adjust your dose based on your response. The maximum dose is 20 mg. Vardenafil shouldn’t be taken more than once a day at any dose. The typical starting dose is 10 mg by mouth about 1 hour before sexual activity. Your provider will adjust your dose based on your response. The maximum dose is 20 mg. .