Sildenafil acts as the active ingredient in Silagra 100mg. Silagra is taken one hour before sex. Which has an effect after taking. The effect lasts for 5-6 hours after taking it. Is the best drug used by men. These pills should be kept away from small children and pets. Silagra 100 Mg is the best drug used only by men. Silagra 100 is widely used by men. It is advisable to use it only once a day.