young, premenopausal amenorrheic athletes, and may be more effective than an oral estrogen with progestin. Hormonal birth control Contraceptive patches such as norelgestromin/ethinylestradiol are a form of estrogen patch which are used for hormonal birth control. Patches with progestogens Taking a progestogen in addition to an estrogen patch should be considered for women who have not undergone a hysterectomy to regulate the thickness of the endometrial lining and reduce the risk of endometrial cancer. Hysterectomized women rarely need a progestogen, however it may be considered if a history of endometriosis exists. There are different types of delivery systems of progestogens that can be used in addition to an estrogen patch, including pills, injections, and patches, among others. Research has suggested that estrogen plus progestogen therapy may increase the risk of heart attacks, stroke, breast cancer, blot clots, and dementia in postmenopausal women. Taking the lowest effective dose of both estrogen and a progestogen may reduce risks. Administration Depending on the brand, patches are applied to the skin once or twice weekly. Patches should be placed on clean skin where hair and moisture is not present. Preferred areas of application include lower abdomen, hip, and buttocks. Patches should never be applied to the breasts. To reduce the risk of the patch detaching from the skin and skin irritation, skin care products, sun exposure, damaged skin, and tight-fitting clothing should be avoided where the patch is placed. Side effects Headache, breast pain or tenderness, nausea, vomiting, hair loss, vaginal discharge or irritation, and mood changes are some of the common side effects that may occur while using an estrogen patch. More serious side effects may include fever, loss of appetite, joint pain, difficulty breathing or swallowing, and yellowing of the skin or eyes. Seeing a health professional regularly, taking progestin, having pelvic and breast exams, lowering blood pressure, and lowering cholesterol may reduce the likelihood of developing severe side effects while using an estrogen patch. Precautions Women who have experienced vaginal bleeding post menopause, certain cancers, stroke, heart attack, blood clotting, or uncontrollable bleeding, and women who are pregnant or allergic to ingredients in estrogen patches should not use an estrogen patch as serious adverse effects may occur. Society and culture Brand names Estrogen patches are available in multiple brand names in different countries. Some patches are available with a progestin such as levonorgestrel, norethisterone acetate, or norelgestromin. See also Pharmacokinetics of