Worst Pills, Best Pills

An expert, independent second opinion on more than 1,800 prescription drugs, over-the-counter medications, and supplements

Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Generic drug name: estradiol [cream; vaginal]
GENERIC: not available
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: conjugated estrogens (CON ju gate ed ES troe jenz)
Brand name(s): PREMARIN
GENERIC: not available FAMILY: Estrogens
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: estradiol [patch] (es TRA di ole trans DER mal)
Brand name(s): CLIMARA
GENERIC: not available FAMILY: Estrogens
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: synthetic conjugated estrogens (sin THE tik CON ju gate ed ES troe jenz)
Brand name(s): CENESTIN
GENERIC: not available FAMILY: Estrogens
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Pregnancy Warning

Because of the potential for serious adverse effects to the fetus, estrogens should not be used by pregnant women.

Breast-feeding Warning

Estrogens are excreted in breast milk and have caused adverse effects on the nursing infant including jaundice and breast enlargement. If possible, the nursing mother should be advised not to use oral contraceptives but to use other forms of contraception until she has completely weaned her child.

Safety Warnings For This Drug [top]



Endometrial Cancer

There is an increased risk of endometrial cancer in a woman with a uterus who uses unopposed estrogens. Adding a progestin to estrogen therapy has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer. Adequate diagnostic measures, including directed or random endometrial sampling when indicated, should be undertaken to rule out malignancy in postmenopausal women with undiagnosed persistent or recurring abnormal genital bleeding.

Cardiovascular Disorders and Probable Dementia

Estrogen-alone therapy should not be used for the prevention of cardiovascular disease or dementia.

The Women's Health Initiative (WHI) estrogen-alone substudy reported increased risks of stroke and deep vein thrombosis (blood clots in large veins, most often in the legs) in postmenopausal women (50 to 79 years of age) during 7.1 years of treatment with daily oral conjugated estrogens (0.625 mg) alone, relative to placebo.

The WHI Memory Study (WHIMS) estrogen-alone ancillary study of WHI reported an increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 5.2 years of treatment with daily conjugated estrogens (0.625 mg) alone, relative to placebo. It is unknown whether this finding applies to younger postmenopausal women.

In the absence of comparable data, these risks should be assumed to be similar for other doses of conjugated estrogens and other dosage forms of estrogens.

Estrogens with or without progestins should be prescribed at the lowest effective doses and for the shortest duration consistent with treatment goals and risks for the individual woman.

Beware of Compounding Pharmacists Selling "Bioidentical" Hormone Replacement Therapies, Claiming That They Are Safe

Pharmacy compound products are not approved by the FDA and their quality is questionable, as they are not produced in facilities meeting good manufacturing practice (GMP) guidelines.

Facts About This Drug [top]

The The oral and vaginal cream estrogen products are approved by the Food and Drug Administration (FDA) to manage the symptoms of menopause. Conjugated estrogens (PREMARIN) and estradiol [patch] (CLIMARA) are also approved to prevent osteoporosis. However, estrogens are not approved by the FDA for the treatment of osteoporosis.

Treatment with Premarin and Climara for the prevention of postmenopausal osteoporosis should be considered only for women at significant risk of osteoporosis and...

The The oral and vaginal cream estrogen products are approved by the Food and Drug Administration (FDA) to manage the symptoms of menopause. Conjugated estrogens (PREMARIN) and estradiol [patch] (CLIMARA) are also approved to prevent osteoporosis. However, estrogens are not approved by the FDA for the treatment of osteoporosis.

Treatment with Premarin and Climara for the prevention of postmenopausal osteoporosis should be considered only for women at significant risk of osteoporosis and for whom non-estrogen medications are not considered to be appropriate.[1],[2]

The mainstays for decreasing the risk of postmenopausal osteoporosis are weight-bearing exercise, adequate calcium and vitamin D intake, and, when needed, treatment with drugs. Postmenopausal women require an average of 1,500 milligrams per day of elemental calcium. Therefore, when not contraindicated, calcium supplementation may be helpful for women with suboptimal dietary intake. Vitamin D supplementation of 400–800 international units per day also may be required to ensure adequate daily intake in postmenopausal women.[1],[2]

The Canadian Task Force on Preventive Health Care recommends “against the use of combined estrogen-progestin therapy and estrogen-only therapy for the primary prevention of chronic diseases in menopausal women.” For the management of the symptoms of menopause, this task force recommends the following: “If the risks are acceptable to the woman and her physician, therapy of as short a duration as possible, and at as low a dose as possible, may be indicated.”[3] We agree.

The North American Menopause Society (NAMS) has issued its position on the management of hot flashes in postmenopausal women. Lifestyle-related strategies such as keeping the core body temperature cool, participating in regular exercise and using paced respiration have shown some effectiveness for mild hot flashes without adverse effects.[4]

The NAMS found that among nonprescription remedies, clinical trial results are insufficient to either support or refute the efficacy of soy foods and isoflavone supplements (from either soy or red clover), black cohosh (AWARENESS FEMALE BALANCE, ESTROVEN, REMIFEMIN) or vitamin E. Single clinical trials have found no benefit for dong quai, evening primrose oil, ginseng, a Chinese herbal mixture, acupuncture or magnet therapy for hot flashes.[4]

There is little evidence to support the effectiveness of topical progesterone cream for hot flashes (see progesterone [PROMETRIUM]). A number of prescription drugs have been tried for hot flashes, but none are approved by the FDA for this use.

For moderate-to-severe hot flashes, the NAMS recommends treatment with oral estrogen, alone or combined with a progestin, or in the form of estrogen-progestin oral contraceptives.[4] These treatments are effective.

Research published in the November 2005 issue of the medical journal Obstetrics & Gynecology found that estrogen plus progestin therapy in postmenopausal women, known as hormone replacement therapy (HRT), increases the risk of urge and stress urinary incontinence within four months of beginning treatment.

Because the risks of HRT outweigh its benefits for most uses, these products now have a black-box warning that appears above their professional product labels. The FDA has also limited the approved uses of HRT to the short-term treatment of moderate-to-severe hot flashes associated with menopause. HRT is no longer approved for the long-term treatment of the symptoms of menopause. The FDA cautions prescribers that women with postmenopausal osteoporosis should use other products, such as alendronate (FOSAMAX), before resorting to HRT. In other words, HRT is the last choice for postmenopausal osteoporosis.[5]

Information from the Women’s Health Initiative trial showed that postmenopausal women who used daily estrogens for several years had an increased risk of endometrial cancer, stroke, deep vein thrombosis (blood clots in large veins, most often in the legs) and probable dementia compared with women receiving a placebo.[6]

Another study, published in the Journal of the American Medical Association, reported that patients on hormone therapy were at an increased risk of ovarian cancer. [7]

The drug product information for estradiol (ESTRADERM) includes postmarketing cases of anaphylaxis reactions requiring emergency medical treatment that occurred during treatment with Estraderm. Concerns about this drug include skin problems (hives; pruritis; and swollen lips, tongue and face) as well as problems with the respiratory tract (respiratory compromise) or the gastrointestinal tract (abdominal pain, vomiting).[8]

An article in the January 2014 issue of Worst Pills, Best Pills News reviewed the risks and benefits of HRT. Two major clinical trials published in 2002 and 2004 revealed a high incidence of breast cancer and stroke with long-term use of HRT. Although HRT use is now much lower than either before or immediately after the 2002 study, the number of prescriptions for HRT remains troublingly high and may be increasing. HRT should therefore be used at the lowest dose and for the shortest duration necessary to meet treatment goals. (To read more, go to Hormone Replacement Therapy: Use at the Lowest Dose for the Shortest Amount of Time, Worst Pills, Best Pills News, January 2014.)[9]

The October 2015 issue of Worst Pills, Best Pills News presented information from a study published in March 2015 in the Cochrane Database of Systematic Reviews showing that hormone therapy does not protect postmenopausal women against cardiovascular disease and can actually result in an increased risk of cardiovascular harm.[10]

In 2019, Lancet published a study showing that the longer the use of all types of hormone therapy (except vaginal estrogen, such as estradiol vaginal cream [ESTRACE]), the higher the risk of invasive breast cancer (breast cancer that spreads into surrounding breast tissue). It also found that combination hormone therapy is associated with a higher breast cancer risk than estrogen-only therapy.[11]

In 2020, JAMA published an article warning that the use of combination estrogen and medroxyprogesterone increased the risk of breast cancer but made no difference in breast cancer death in women with a uterus compared with use of a placebo. Use of estrogen alone had a lower risk of breast cancer and breast cancer death in women who had a hysterectomy compared with use of a placebo.[12]

Before You Use This Drug [top]

Do not use if you have or have had:

  • blood-clotting disorder (does not apply to cream preparations)
  • abnormal and undiagnosed vaginal bleeding
  • cancer
  • allergy to parabens or other components (cream preparations)

Tell your doctor if you have or have had:

  • pregnancy or are breast-feeding
  • allergies to drugs
  • endometriosis
  • gallstones or gallbladder disease (oral; patch)
  • liver disease
  • jaundice (oral; patch)
  • high cholesterol or triglycerides (oral; patch)
  • pancreatitis (oral; patch)
  • high levels of calcium in the blood (oral; patch)
  • uterine fibroids
  • blood-clotting problems
  • vaginal problems (cream)
  • asthma
  • epilepsy
  • cardiac or renal problems
  • migraine
  • diabetes
  • thyroid problems

Tell your doctor about any other drugs you take,  including aspirin, herbs, vitamins, and other nonprescription products.

When You Use This Drug [top]

  • Perform regular breast self-examinations.
  • See your doctor on a regular basis.
  • Stop drug immediately if you think you are pregnant.
  • Do not use latex condoms for up to 72 hours after using this drug because oils in the cream can weaken the condom (cream).
  • Use cream after sexual intercourse, not before (cream).
  • Full therapeutic effect can take three to four months to appear (cream).
  • Have regular dental examinations (oral; patch).
  • Menstrual bleeding may begin again, but if you are on continuous therapy, it will stop by 10 months (oral; patch)
  • Bleeding during a menstrual cycle may occur during the first three months of therapy (oral; patch)
  • May affect lab test results, tell your doctor you are taking this drug

How to Use This Drug [top]

  • If you miss a dose, take it as soon as you remember, but skip it if it is almost time for the next dose. Do not take double doses.
  • Do not share your medication with others.
  • Take the drug at the same time(s) each day.
  • Store at room temperature with lid or cap on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

For oral:

  • Take with food or milk.

For patch:

  • Wash hands immediately before and after administration.
  • Apply patch to clean, dry, nonoily, hairless, intact skin.
  • Follow manufacturer’s instructions as to where on skin to apply patch.
  • Do not apply to breasts.
  • Press patch firmly in place.
  • Reapply patch if it comes loose, or discard and apply a new one.
  • To prevent skin irritation, rotate patch application sites.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

BIAXIN, carbamazepine, clarithromycin, EES, erythromycin, EVISTA, grapefruit juice, Hypericum perforatum, itraconazole, ketoconazole, LUMINAL, NIZORAL, NORVIR, phenobarbital, raloxifene, RIFADIN, rifampin, RIMACTANE, ritonavir, SPORANOX, St. John’s wort, TEGRETOL.

Adverse Effects [top]

Call your doctor immediately if you experience:

  • breast pain or enlargement
  • rapid weight gain (patch; oral)
  • swelling of feet and lower legs (patch; oral)
  • stopping of menstrual bleeding (patch; oral)
  • breakthrough menstrual bleeding (patch; oral)
  • prolonged or heavy menstrual bleeding (patch; oral)
  • breast lumps (patch; oral)
  • breast discharge (patch; oral)
  • stomach, side, or abdominal pain (patch; oral)
  • yellow eyes or skin (patch; oral)

Call your doctor if these symptoms continue:

  • abdominal cramping or bloating (patch; oral)
  • loss of appetite (patch; oral)
  • nausea (patch; oral)
  • skin irritation and redness (patch)
  • mild diarrhea (patch; oral)
  • mild dizziness (patch; oral)
  • mild headache (patch; oral)
  • intolerance to wearing contact lenses (patch; oral)
  • increased sexual response (patch; oral)
  • migraine headaches (patch; oral)
  • vomiting (patch; oral)

Periodic Tests[top]

Ask your doctor which of these tests should be done periodically while you are taking this drug:

  • breast examination
  • mammogram
  • Pap test
  • physical examination
  • endometrial biopsy
  • blood pressure (patch; oral)
  • liver function test (patch; oral)
  • lipid levels (patch; oral)

last reviewed April 30, 2023