How do birth control patches (patch, ortho evra) work?
The hormones in the birth control patches work by preventing a woman’s ovaries from ovulating or releasing eggs. Hormones thicken the cervical mucus which prevents sperm from joining with an egg. Hormones also thin the lining of the uterus. Contraceptive patches applied to the skin get hormones into the blood stream and are removed from the body differently than hormones from birth control pills taken orally. The birth control hormone patch works optimally when it is changed on the same day of the week for three weeks in a row. Pregnancy can happen if an error is made in using the birth control contraceptive patch especially if it becomes loose or falls off for more than 24 hours and/or the same patch is left on the skin for more than one week, therefore, losing its effectiveness.
