Filagra is a drug that specializes in the treatment of impotence or erectile dysfunction in men. The active ingredient of this drug is sildenafil which is responsible for achieving and maintaining an erection by increasing blood flow to the penile region. This medicine is taken 30 minutes or 1 hour before intercourse. The effect of this medicine lasts for 4 to 6 hours. You can take this medicine before or after food. You can take this medicine before or after food. Take this medicine as advised by the doctor.