femring
Femring (Estradiol Acetate) is an estrogen used to treat Breast Neoplasms, Hypogonadism, Premature Menopause, Menorrhagia.
Estradiol Acetate · by Millicent Mfg Pr
Key facts
- Active ingredient
- Estradiol Acetate
- Drug class
- Estrogen
- Form
- Ring
- Strength
- Estradiol Acetate EQ 0.05MG BASE/24HR · Estradiol Acetate EQ 0.1MG BASE/24HR
- Type
- Prescription (Rx)
- Brand or generic
- Brand-name
- May treat
- breast neoplasms, hypogonadism, premature menopause
- Manufacturer
- Millicent Mfg Pr
- What the pharmacy pays
- ~$6.55 per gm — not your price
- FDA application
- NDA021367
- FDA boxed warning
- Yes — see the boxed warning
What is Femring?
From the FDA label:Femring (estradiol acetate vaginal ring) is an off-white, soft, flexible ring with a central core containing estradiol acetate. Femring is made of cured silicone elastomer composed of dimethyl polysiloxane silanol, silica (diatomaceous earth), normal propyl orthosilicate, stannous octoate; barium sulfate and estradiol acetate. The rings have the following dimensions: outer diameter 56 mm, cross-sectional diameter 7.6 mm, core diameter 2 mm. Femring is available in two strengths: Femring 0.05 mg/day has a central core that contains 12.4 mg of estradiol acetate, which releases at a rate equivalent to 0.05 mg of estradiol per day for 3 months. Femring 0.10 mg/day has a central core that contains 24.8 mg of estradiol acetate, which releases at a rate equivalent to 0.10 mg of estradiol per day for 3 months. Estradiol acetate is chemically described as estra-1,3,5(10)-triene-3,17β-diol-3-acetate. The molecular formula of estradiol acetate is C 20 H 26 O 3 and the molecular weight of estradiol acetate is 314.42. The Structural formula of Estradiol acetate is chemically described as estra-1,3,5(10)-triene-3,17b-diol-3-acetate
How to use
Generally, when estrogen is prescribed for a postmenopausal woman with a uterus, a progestin should also be considered to reduce the risk of endometrial cancer. A woman without a uterus does not need a progestin. In some cases, however, hysterectomized women with a history of endometriosis may need a progestin [see Warnings and Precautions (5.2 , 5.14 )]. Use of estrogen-alone, or in combination with a progestin, should be with the lowest effective dose and for the shortest duration consistent with treatment goals and risks for the individual woman. Postmenopausal women should be re-evaluated periodically as clinically appropriate to determine if treatment is still necessary. • One ring inserted into the vagina for 3 months. Patients should be started at the lowest dose. ( 2.1 , 2.2 ) 2.1 Treatment of Moderate to Severe Vasomotor Symptoms due to Menopause Start therapy with 0.05 mg/day. Dosage adjustment should be guided by the clinical response. Therapy should be started at the lowest effective dose and the shortest duration consistent with treatment goals. Attempts to taper or discontinue the medication should be made at 3 to 6 month intervals. 2.2 Treatment of Moderate to Severe Vulvar and Vaginal Atrophy due to Menopause. Start therapy with 0.05 mg/day. Dosage adjustment should be guided by the clinical response. Therapy should be started at the lowest effective dose and…
Side effects
The following serious adverse reactions are discussed elsewhere in the labeling: • Cardiovascular Disorders [see Boxed Warning , Warnings and Precautions (5.1) ]. • Malignant Neoplasms [see Boxed Warning , Warnings and Precautions (5.2) ]. Most common adverse reactions (incidence > 5 percent) are vaginal bleeding and breast tenderness. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Millicent at 1-877-810-2101 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. In a 13-week clinical trial that included 225 postmenopausal women treated with Femring and 108 women treated with placebo vaginal rings, adverse reactions that occurred at a rate of ≥ 2 percent are summarized in Table 1 . Table 1. Incidence of Adverse Reactions Occurring in ≥ 2 Percent of Subjects Presented in Descending Frequency of Preferred Term AE = adverse event; NOS = not otherwise specified Adverse Event Placebo (n = 108) Estradiol 0.05 mg/day (n = 113) Estradiol 0.10 mg/day (n = 112) n (percent) n (percent) n (percent) Headache (NOS) 10 (9.3) 8 (7.1) 11 (9.8) Intermenstrual Bleeding 2 (1.9) 9 (8.0) 11 (9.8) Vaginal…
FDA Boxed Warning (the FDA’s most serious warning)
Boxed (black-box) warning — from the FDA label
Estrogen-Alone Therapy 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 [see Warnings and Precautions (5.2) ] . Cardiovascular Disorders and Probable Dementia Estrogen-alone therapy should not be used for the prevention of cardiovascular disease or dementia [see Warnings and Precautions (5.1 , 5.3 ), and Clinical Studies (14.3 , 14.4 )] . The Women’s Health Initiative (WHI) estrogen-alone substudy reported increased risks of stroke and deep vein thrombosis (DVT) in postmenopausal women (50 to 79 years of age) during 7.1 years of treatment with daily oral conjugated estrogens (CE) [0.625 mg]-alone, relative to placebo [see Warnings and Precautions (5.1) , and Clinical Studies (14.3) ]. The WHI Memory Study (WHIMS) estrogen-alone ancillary study of the 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 CE (0.625 mg)-alone, relative to placebo. It is unknown whether this finding applies to younger postmenopausal women [see Warnings and Precautions (5.3) , Use in Specific Populations (8.5) , and Clinical Studies (14.4) ]. In the absence of comparable data, these risks should be assumed to be similar for other doses of CE 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. Estrogen Plus Progestin Therapy Cardiovascular Disorders and Probable Dementia Estrogen plus progestin therapy should not be used for the prevention of cardiovascular disease or dementia [see Warnings and Precautions (5.1 , 5.3 ) and Clinical Studies (14.3 , 14.4 )] . The WHI estrogen plus progestin substudy reported increased risks of DVT, pulmonary embolism (PE), stroke and myocardial infarction (MI) in postmenopausal women (50 to 79 years of age) during 5.6 years of treatment with daily oral CE (0.625 mg) combined with medroxyprogesterone acetate (MPA) [2.5 mg], relative to placebo [see Warnings and Precautions (5.1) , and Clinical Studies (14.3) ] . The WHIMS estrogen plus progestin ancillary study of the WHI reported increased risk of developing probable dementia in postmenopausal women 65 years of age or older during 4 years of treatment with daily CE (0.625 mg) combined with MPA (2.5 mg), relative to placebo. It is unknown whether this finding applies to younger postmenopausal women [see Warnings and Precautions (5.3) , Use in Specific Populations (8.5) and Clinical Studies (14.4) ] . Breast Cancer The WHI estrogen plus progestin substudy also demonstrated an increased risk of invasive breast cancer [see Warnings and Precautions (5.3) , and Clinical Studies (14.3) ]. In the absence of comparable data, these risks should be assumed to be similar for other doses of CE and MPA and other combinations and dosage forms of estrogens and progestins. 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. WARNING: ENDOMETRIAL CANCER, CARDIOVASCULAR DISORDERS, BREAST CANCER, AND PROBABLE DEMENTIA See full prescribing information for complete boxed warning. Estrogen-Alone Therapy • There is an increased risk of endometrial cancer in a woman with a uterus who uses unopposed estrogens ( 5.2 ) • Estrogen-alone therapy should not be used for the prevention of cardiovascular disease or dementia ( 5.1 , 5.3 ) • The Women’s Health Initiative (WHI) estrogen-alone substudy reported increased risks of stroke and deep vein thrombosis (DVT) ( 5.1 ) • The WHI Memory Study (WHIMS) estrogen-alone ancillary study of WHI reported an increased risk of probable dementia in postmenopausal women 65 years of age and older ( 5.3 ) Estrogen Plus Progestin Therapy • Estrogen plus progestin therapy should not be used for the prevention of cardiovascular disease or dementia ( 5.1 , 5.3 ) • The WHI estrogen plus progestin substudy reported increased risks of stroke, DVT, pulmonary embolism (PE), and myocardial infarction (MI) ( 5.1 ) • The WHI estrogen plus progestin substudy reported an increased risk of invasive breast cancer ( 5.2 ) • The WHIMS estrogen plus progestin ancillary study of WHI reported an increased risk of probable dementia in postmenopausal women 65 years of age and older ( 5.3 )
Warnings
Important safety information
Femring is used only in the vagina, however, the risks associated with oral estrogens should be taken into account. • Estrogens increase the risk of gallbladder disease ( 5.4 ) • Discontinue estrogen if severe hypercalcemia, loss of vision, severe hypertriglyceridemia or cholestatic jaundice occurs ( 5.5 , 5.6 , 5.9 , 5.10 ) • Monitor thyroid function in women on thyroid replacement therapy ( 5.11 , 5.18 ) 5.1 Cardiovascular Disorders An increased risk of stroke and DVT has been reported with estrogen-alone therapy. An increased risk of PE, DVT, stroke, and MI has been reported with estrogen plus progestin therapy. Should any of these occur or be suspected, estrogen with or without progestin therapy should be discontinued immediately. Risk factors for arterial vascular disease (for example, hypertension, diabetes mellitus, tobacco use, hypercholesterolemia, and obesity) and/or venous thromboembolism (VTE) (for example, personal history or family history of VTE, obesity, and systemic lupus erythematosus) should be managed appropriately. Stroke In the WHI estrogen-alone substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving daily CE (0.625 mg)-alone compared to women in the same age group receiving placebo (45 versus 33 per 10,000 women-years). The increase in risk was demonstrated in year 1 and persisted [see Clinical Studies (14.3) ] . Should a stroke occur or be suspected, estrogen-alone therapy should be discontinued immediately. Subgroup analyses of women 50 to 59 years of age suggest no increased risk of stroke for those women receiving CE (0.625 mg)-alone versus those receiving placebo (18 versus 21 per 10,000 women-years). 1 In the WHI estrogen plus progestin substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women in the same age group receiving placebo (33 versus 25 per 10,000 women-years) [see Clinical Studies (14.3) ] . The increase in risk was demonstrated after the first year and persisted. 1 Should a stroke occur or be suspected, estrogen plus progestin therapy should be discontinued immediately. Coronary Heart Disease In the WHI estrogen-alone substudy, no overall effect on coronary heart disease (CHD) events (defined as nonfatal MI, silent MI, or CHD death) was reported in women receiving estrogen-alone compared to placebo 2 [see Clinical Studies (14.3) ]. Subgroup analyses of women 50 to 59 years of age suggest a statistically non-significant reduction in CHD events (CE [0.625 mg]-alone compared to placebo) in women with less than 10 years since menopause (8 versus 16 per 10,000 woman-years). 1 In the WHI estrogen plus progestin substudy, there was a statistically non-significant increased risk of CHD events reported in women receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women receiving placebo (41 versus 34 per 10,000 women-years). 1 An increase in relative risk was demonstrated in year 1, and a trend toward decreasing relative risk was reported in years 2 through 5 [see Clinical Studies (14.3) ]. In postmenopausal women with documented heart disease (n = 2,763, average 66.7 years of age), in a controlled clinical trial of secondary prevention of cardiovascular disease (Heart and Estrogen/Progestin Replacement Study; HERS) treatment with daily CE (0.625 mg) plus MPA (2.5 mg) demonstrated no cardiovascular benefit. During an average follow-up of 4.1 years, treatment with CE plus MPA did not reduce the overall rate of CHD events in postmenopausal women with established CHD. There were more CHD events in the CE plus MPA-treated group than in the placebo group in year 1, but not during the subsequent years. Two thousand, three hundred and twenty-one (2,321) women from the original HERS trial agreed to participate in an open label extension of HERS, HERS II. Average follow-up in HERS II was an additional 2.7 years, for a total of 6.8 years overall. Rates of CHD events were comparable among women in the CE plus MPA group and the placebo group in HERS, HERS II, and overall. Venous Thromboembolism In the WHI estrogen-alone substudy, the risk of VTE (DVT and PE), was increased for women receiving daily CE (0.625 mg)-alone compared to placebo (30 versus 22 per 10,000 women-years), although only the increased risk of DVT reached statistical significance (23 versus 15 per 10,000 women-years). The increase in VTE risk was demonstrated during the first 2 years 3 [see Clinical Studies (14.3) ] . Should a VTE occur or be suspected, estrogen-alone therapy should be discontinued immediately. In the WHI estrogen plus progestin substudy, a statistically significant 2-fold greater rate of VTE was reported in women receiving daily CE (0.625 mg) plus MPA (2.5 mg) compared to women receiving placebo (35 versus 17 per 10,000 women-years). Statistically significant increases in risk for both DVT (26 versus 13 per 10,000 women-years) and PE (18 versus 8 per 10,000 women-years) were also demonstrated. The increase in VTE risk was demonstrated during the first year and persisted 4 [see Clinical Studies (14.3) ] . Should a VTE occur or be suspected, estrogen plus progestin therapy should be discontinued immediately. If feasible, estrogens should be discontinued at least 4 to 6 weeks before surgery of the type associated with an increased risk of thromboembolism, or during periods of prolonged immobilization. 5.2 Malignant Neoplasms Endometrial Cancer An increased risk of endometrial cancer has been reported with the use of unopposed estrogen therapy in a woman with a uterus. The reported endometrial cancer risk among unopposed estrogen users is about 2 to 12 times greater than in non-users, and appears dependent on duration of treatment and on estrogen dose. Most studies show no significant increased risk associated with use of estrogens for less than 1 year. The greatest risk appears associated with prolonged use, with increased risks of 15- to 24-fold for 5 to 10 years or more. This risk has been shown to persist for at least 8 to 15 years after estrogen therapy is discontinued. Clinical surveillance of all women using estrogen-alone or estrogen plus progestin therapy is important. 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. There is no evidence that the use of natural estrogens results in a different endometrial risk profile than synthetic estrogens of equivalent estrogen dose. Adding a progestin to estrogen therapy in postmenopausal women has been shown to reduce the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer. Breast Cancer The WHI substudy of daily CE (0.625 mg)-alone provided information about breast cancer in estrogen-alone users. In the WHI estrogen-alone substudy, after an average follow up of 7.1 years, daily CE-alone was not associated with an increased risk of invasive breast cancer (relative risk [RR] 0.80) 5 [see Clinical Studies (14.3) ] . After a mean follow-up of 5.6 years, the estrogen plus progestin substudy reported an increased risk of invasive breast cancer in women who took daily CE plus MPA. In this substudy, prior use of estrogen-alone or estrogen plus progestin therapy was reported by 26 percent of the women. The relative risk of invasive breast cancer was 1.24, and the absolute risk was 41 versus 33 cases per 10,000 women-years for CE plus MPA compared with placebo. Among women who reported prior use of hormone therapy, the relative risk of invasive breast cancer was 1.86 and the absolute risk was 46 versus 25 cases per 10,000 women-years for CE plus MPA compared with placebo. Among women who reported no prior use of hormone therapy, the relative risk of invasive breast cancer was 1.09, and the absolute risk was 40 versus 36…
Who should not take Femring
Femring is contraindicated in women with any of the following conditions: • Undiagnosed abnormal genital bleeding • Known, suspected, or history of breast cancer • Known or suspected estrogen-dependent neoplasia • Active DVT, PE, or history of these conditions • Active arterial thromboembolic disease (for example, stroke and MI), or a history of these conditions • Known anaphylactic reaction or angioedema to Femring • Known liver impairment or disease • Known protein C, protein S, or antithrombin deficiency, or other known thrombophilic disorders • Known or suspected pregnancy • Undiagnosed abnormal genital bleeding ( 4 ) • Known, suspected, or history of breast cancer ( 4 , 5.2 ) • Known or suspected estrogen-dependent neoplasia ( 4 , 5.2 ) • Active DVT, PE, or history of these conditions ( 4 , 5.1 ) • Active arterial thromboembolic disease (for example, stroke and MI), or a history of these conditions ( 4 , 5.1 ) • Known anaphylactic reaction or angioedema to Femring ( 4 ) • Known liver impairment or disease ( 4 , 5.10 ) • Known protein C, protein S, or antithrombin deficiency, or other known thrombophilic disorders ( 4 ) • Known or suspected pregnancy ( 4 , 8.1 )
Overdose — what happens if you take too much
Overdosage of estrogen may cause nausea, vomiting, breast tenderness, dizziness, abdominal pain, drowsiness and fatigue, and withdrawal bleeding may occur in women. Treatment of overdose consists of discontinuation of Femring with institution of appropriate symptomatic care.
U.S. Poison Control: call or text 1-800-222-1222 (free, 24/7). In an emergency call 911. From the FDA label; not medical advice.
Interactions
No drug interaction studies have been conducted for Femring. • Inducers and/or inhibitors of CYP3A4 may affect estrogen drug metabolism ( 7.1 ) 7.1 Metabolic Interactions In vitro and in vivo studies have shown that estrogens are metabolized partially by cytochrome P450 3A4 (CYP3A4). Therefore, inducers or inhibitors of CYP3A4 may affect estrogen drug metabolism. Inducers of CYP3A4 such as St. John’s wort ( Hypericum perforatum ) preparations, phenobarbital, carbamazepine and rifampin may decrease the plasma concentration of estrogens, possibly resulting in a decrease in therapeutic effects and/or changes in the uterine bleeding profile. Inhibitors of CYP3A4 such as erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir and grapefruit juice may increase the plasma concentration of estrogens and may result in side effects.
Drug class
How this class works, per Estrogen - StatPearls - NCBI Bookshelf.
May treat (source: NIH RxClass)
- breast neoplasms
- hypogonadism
- premature menopause
- menorrhagia
- prostatic neoplasms
- primary ovarian insufficiency
See how Femring ranks — best-rated estrogen for:
Dosage forms
Ring
The forms currently marketed in the U.S., per the FDA National Drug Code Directory.
Ways to save
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Request a 90-day supply
Bulk fills usually lower the per-dose price vs monthly refills.
Use copay cards
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Frequently asked questions
- What does Femring treat?
- Femring (Estradiol Acetate) may be used to treat breast neoplasms, hypogonadism, premature menopause, menorrhagia, prostatic neoplasms, primary ovarian insufficiency, based on NIH RxClass drug-classification data (conditions a drug may treat — not a verbatim copy of the FDA-approved label). This is general reference, not medical advice.
- How does Femring work?
- Femring is a estrogen. Estrogen is a sex hormone that enters cells and binds estrogen receptors; the hormone-receptor complex then moves into the nucleus and switches target genes on or off. Through this it thickens the uterine lining, helps protect bone, supports breast and vaginal tissue, and shapes cholesterol levels.
- How much does Femring cost?
- Nobody can tell you what you will pay — your price is set by your insurer's formulary, your deductible and the pharmacy's markup, and none of those are published. What IS published is what the pharmacy paid to acquire it: about $6.55 per gm, per the CMS NADAC survey. Treat that as the floor, not the quote — ask the pharmacist for the cash price as well as your copay, because for cheap generics the cash price often wins.
- Is there a coupon or discount for Femring?
- pharmaranks is an independent ratings site, not a pharmacy — we don't issue coupons or sell Femring. To pay less, ask your prescriber or pharmacist whether a generic equivalent exists, check the manufacturer's copay/savings card and patient-assistance program, and compare a pharmacy discount card against your insurance copay. Prices vary by pharmacy, insurance, and location, so always confirm at the counter. This is general reference, not medical or financial advice.
- Who makes Femring?
- Femring is marketed by Millicent Mfg Pr. You can see Millicent Mfg Pr's full profile, rating, and other products on pharmaranks.
- Is Femring a brand-name or generic drug?
- Femring is a brand-name product with the active ingredient Estradiol Acetate.
- Is Femring available over the counter?
- No. Femring is a prescription (Rx) medication in the US — you need a prescription from a licensed clinician (in person or via telehealth); it isn't sold over the counter. For some conditions there are OTC alternatives — ask your pharmacist.
- What forms does Femring come in?
- Femring is currently marketed as ring, per the FDA's National Drug Code Directory.
- What class of drug is Femring?
- Femring is classified as estrogen, per the FDA's Established Pharmacologic Class.
- Is Femring FDA-registered?
- Femring is on record with the U.S. FDA under application number NDA021367. You can verify this on its official FDA label.
- Is Femring safe?
- There's no single safe-or-not verdict, and we don't yet have a composite recall-safety score for Femring. Review its FDA-label side effects and warnings below, and always consult a licensed professional.
- What are the side effects of Femring?
- Femring's side effects are taken directly from its FDA label. From the label: The following serious adverse reactions are discussed elsewhere in the labeling: • Cardiovascular Disorders [see Boxed Warning , Warnings and Precautions (5.1) ]. • Malignant Neoplasms [see Boxed Warning , Warnings and Precautions (5.2) ].… Both common and serious reactions are documented in full on this page. This is general reference from the FDA, not medical advice — always consult a professional.
Clinical content sourced from the FDA label via openFDA (U.S. FDA). View the FDA label on DailyMed → Provided for general reference only — not medical advice. Always consult a licensed professional and the current prescribing information.
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