A nerve block relieves pain by interrupting how pain signals are sent to your brain. It is done by injecting a substance, such as alcohol or phenol, into or around a nerve or into the spine. Nerve blocks may be used for several purposes, such as: 1  To determine the source of pain.
2.5 Stars. Lo Loestrin Fe is the brand name for norethindrone acetate and ethinyl estradiol, a prescription birth control medicine that's used to prevent pregnancy. The drug contains female hormones that prevent ovulation and also causes changes in the cervical mucus and uterine lining, which makes it harder for sperm to reach the uterus and for a fertilized egg to attach to the uterus.
The better you follow the directions, the less chance you have of getting pregnant. 1 Women with a body mass index (BMI) above 35 kg/m 2 were not studied in the clinical trial, so it is not known how well Lo Loestrin Fe protects against pregnancy in such women.