History Sildenafil compound UK, was synthesized by a group of pharmaceutical chemists led by Simon Campbell [55] working at Pfizer’s Sandwich, Kent , research facility in England. Because they are the same class of medications, they have similar side effects and effectiveness. Pfizer Canada Inc. Talk with your healthcare provider about which might be best for you. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. However, it stays in your body for up to 36 hours and can be taken every 24 hours, so it can work for you constantly. Talk with your healthcare provider about your sex life and desired use.Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum . The Savings Offer and Program expire on 12/31/ For further information, call , visit test1.ru, or write: Viatris Inc., P.O. Box , Mission, KS . Typical dosing for Sildenafil (Viagra) The typical dose is to take 50 mg of sildenafil (Viagra) by mouth, about 1 hour before sex, as needed. The maximum .