Sildenafil comes in usually three dosages, 25 mg, 50mg, and 100mg doses. You can never take more than 100ms sildenafil in a day. This medication is prescribed for the treatment of erectile dysfunction in men. It is usually taken an hour before indulging in sexual intercourse for better and more sustained erection, during sexual intercourse. However, sildenafil works well only if you have had a...