Hormonal (combined estrogen and progestin)
What exactly is "The Patch"?
The patch can be placed on the upper outer arm, abdomen, buttock or back. The patch lasts for a 28-day cycle. They do not protect against STD's. Apply a new patch each week for three weeks (21 total days). Week Four is patch-free. Apply each new patch on the same day of the week. The patch prevents pregnancy by delivering continuous levels of hormones (progestin and estrogen, respectively) into the bloodstream through the skin. Following this process, the Patch works the same way that pills do: by preventing ovulation. They're about 99% effective overall.
It is for female use only, and could potentially cause weight gain, a high risk of arterial or venous thrombotic diseases, Breast cancer or other estrogen- or progestin-sensitive cancer, Liver tumors or liver disease, and undiagnosed abnormal uterine bleeding.