Sildenafil works by relaxing the blood vessels of lungs, which allows easy blood flow. This site is intended only for U. More serious side effects to watch out for include an erection lasting four hours or longer or a painful erection that lasts six or more hours, called priapism. The market research data included in this report is analysed and forecasted using market statistical and coherent models. In addition, only the Sildenafil Cream treatment group in this subset, and not the placebo group, demonstrated clinically meaningful improvement at the end of the week period.Both 50mg and mg of Sildenafil (Viagra) work exactly the same way and last the same amount of time. A key difference is their effectiveness. In clinical studies, 82% of men taking mg of Sildenafil (Viagra) were able to achieve and maintain an erection as opposed to 74% taking 50mg. However, regardless of your prescribed dosage, it’s. Sildenafil is available through Roman by prescription in , , mg pills and ranging in price from $4–$10 per dose. Brand-name Viagra is also available through Roman in ,  · Print Save Sildenafil Dosage Medically reviewed by Last updated on Applies to the following strengths: 10 mg/mL; 10 mg/ mL; 20 mg; 25 mg; 50 mg; mg Usual Adult Dose for: Erectile Dysfunction Pulmonary Hypertension Usual Geriatric Dose for: Erectile Dysfunction Additional dosage .