Purple Viagra Pill is used to treat men's premature ejaculation and erectile dysfunction (ED). An element in this medication called sildenafil helps to relax the muscles in the male penile tissue and increases blood flow to it. If this medication is given 30 minutes or an hour before sexual activity, it works well. This medication takes four to six days to take effect. This medication can be used either before or after meals. Follow your doctor's advice when taking this medication.