Estradiol is a form of estrogen. Estrogen is a female sex hormone that is involved in the development and maintenance of the female reproductive system.
Norethindrone is a form of progesterone. Progesterone is a female hormone important for the regulation of ovulation and menstruation.
Together, estradiol and norethindrone are used to treat the symptoms of menopause such as feelings of warmth in the face, neck and chest, or sudden intense spells of heat and sweating (“hot flashes” or “hot flushes”); to treat vulvar and vaginal changes (itching, burning, dryness in or around the vagina, difficulty or burning with urination) caused by menopause; and to replace estrogen in conditions such as hypogonadism, removal of the ovaries, or primary ovarian failure that result in a lack of estrogen. Estradiol and norethindrone is also used to prevent thinning of the bones (osteoporosis).
- an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives);
- shortness of breath or pain in the chest;
- a painful, red, swollen leg;
- abnormal vaginal bleeding;
- pain, swelling, or tenderness in the abdomen;
- severe headache or vomiting, dizziness, faintness or changes in vision or speech;
- yellowing of the skin or eyes; or
- a lump in a breast.
Other, less serious side effects may be more likely to occur. Continue to take estradiol and norethindrone and talk to your doctor if you experience
- nausea and vomiting;
- tenderness or enlargement of the breasts;
- swelling of the hands or feet;
- spotty darkening of the skin, particularly on the face;
- difficulty in wearing contact lenses;
- vaginal irritation or discomfort; or
- changes in menstrual cycle, painful menstruation, or break-through bleeding.
Estradiol increases the risk of developing endometrial hyperplasia, a condition that may lead to cancer of the lining of the uterus. Using a progestin, such as norethindrone, with estradiol lowers the risk of developing this condition. Visit your doctor regularly and report any unusual vaginal bleeding right away.
It is unclear to what extent estrogen and progesterone treatments may affect the risk of breast cancer.
Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.