purple viagra can be used to treat impotence and erectile dysfunction in men. This medication's ingredient, sildenafil, helps to increase blood flow to men's penile tissue. Take this medication 30 minutes before engaging in any sexual activity. You can take this medication with or without food. Do not chew or crush this medication; instead, take it with water. Cold or fatty foods should not be consumed while taking this medication as they will reduce its effectiveness. You should take this medication as directed by your doctor.