The U.S. Food and Drug Administration has approved two main types of hormone replacement therapy (also known as menopausal hormonal therapy) for symptoms such as hot flashes and night sweats. They are:
- Combination estrogen and progestin therapy. If you haven’t had a hysterectomy, your doctor will prescribe this hormone combination. Estrogen quells symptoms. But because estrogen therapy alone raises the risk of endometrial cancer by causing the uterine lining to grow and thicken, progestin (a synthetic version of the hormone progesterone) is added to counteract that cancer risk. Unfortunately, combined therapy carries a slight risk of breast cancer, which increases after about five years of use—this is why you should use the therapy for only as long as needed.
- Estrogen-only therapy. If you’ve undergone a hysterectomy and no longer have a uterus, you don’t have to be concerned about developing endometrial cancer. In this situation, progestin doesn’t need to be added to estrogen therapy. Also, estrogen-only therapy carries with it a lower breast cancer risk than does combined therapy.
Hormone replacement therapy comes in several forms, including pill, skin patch, gel, cream, lotion, vaginal ring or spray. Although all forms share some common features, each has its own risks and benefits. Topical hormone therapy is considered safer than oral therapy but may be less effective in treating hot flashes.
For example, some evidence suggests that transdermal estrogen has a lower risk of deep vein thrombosis (a blood clot in the leg), stroke and heart attack than oral regimens. No matter what type of hormone replacement therapy you choose, always strive to use the lowest effective dosage for the shortest duration possible.
Other risks associated with combined and estrogen-only therapies include heart attack, pulmonary embolism (blood clots in the lungs) and gallbladder disease. Less serious side effects include breast tenderness, vaginal bleeding, bloating, nausea, and headaches. Lowering the dose may relieve many of these side effects.
If you have a uterus but can’t tolerate progestin, you have a third option. In 2013, the FDA approved Duavee, a conjugated estrogen combined with bazedoxifene, a selective estrogen receptor modulator (SERM), to treat hot flashes and prevent bone loss, or osteoporosis. Duavee’s potential side effects include stomach discomfort, muscle spasms and dizziness. Like other estrogens, it may raise the risk for blood clots.