Filagra is used to treat sexual problems in men. The main ingredient in this medicine is Sildenafil Citrate. This drug dilates the blood in the penile arteries and relaxes the muscles. The time it takes for this drug to work varies from person to person, but it usually takes between 30 minutes and an hour. With the use of this medicine, you can enjoy sex with your partner for a long time. This medicine can be taken only once a day. The effect of this medicine lasts for about 4 hours. This medicine should be used as per the doctor's advice. Using this medicine improves your sex life.