FDA-filed SPL labeling · retrieved through openFDA

Conjugated Estrogens / Medroxyprogesterone

Conjugated estrogens combined with medroxyprogesterone is a hormone therapy used in women with a uterus to treat moderate to severe menopausal symptoms, vaginal and vulvar changes due to menopause, and to help prevent postmenopausal osteoporosis.

Brand names PremproPremphase
Drug class Estrogen
Rx Form 1 Route Oral
Dr. Brian Staiger, PharmD, BCPS
Reviewed by Last reviewed Jul 10, 2026
🧬 Where this information comes from Click to expand

The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →

At a glance
Linked label effectiveApr 28, 2026
AvailabilityRx
Earliest approval/marketing year 2003
FDA-listed product records 20
Boxed warningYes
How we combine label and product data →
No current FDA shortage listed · checked Sep 22, 2026
Conjugated Estrogens / Medroxyprogesterone at a glance The quick version — the full detail is in the Patient Information Guide below.
💊
HelloPharmacist Editorial Team Bottom Line
Prempro is an effective option for managing moderate to severe menopausal symptoms and preventing postmenopausal osteoporosis in women with a uterus, but it carries real risks including blood clots, stroke, breast cancer, and probable dementia in older women. It is not intended to prevent heart disease or dementia, and it should be used at the lowest effective dose for the shortest time your treatment goals require. Regular check-ins with your doctor — along with yearly breast exams and mammograms — are essential while you're on it.
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert

This medication carries serious FDA boxed warnings — the highest-level safety alert. Clinical studies found that women taking estrogen plus progestin (like this combination) had increased risks of stroke, blood clots (DVT and pulmonary embolism), heart attack, invasive breast cancer, and probable dementia. Women 65 and older had a roughly doubled risk of developing probable dementia. This medication should not be used to prevent heart disease or dementia. Separately, estrogen used alone (without a progestin) in women who still have a uterus raises the risk of endometrial cancer (cancer of the uterine lining) — this is why the progestin is included in this combination product. Any unexplained vaginal bleeding should be reported to a doctor right away. Always use the lowest effective dose for the shortest time possible.

Read the full warning on DailyMed →

📖 Conjugated Estrogens / Medroxyprogesterone: Patient Information Guide

A plain-language walkthrough of Conjugated Estrogens / Medroxyprogesterone — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.

🎯What it's used for

Conjugated estrogens / medroxyprogesterone is a combination hormone therapy approved for use in postmenopausal women who have a uterus. Supported uses include:

  • Prempro (oral tablet): Treatment of moderate to severe vasomotor symptoms (hot flashes, night sweats) due to menopause
  • Prempro (oral tablet): Treatment of moderate to severe vulvar and vaginal atrophy (dryness, irritation, tissue thinning) due to menopause — when treating vaginal symptoms only, topical vaginal products should be considered first
  • Prempro (oral tablet): Prevention of postmenopausal osteoporosis — reserved for women at significant risk; non-estrogen medications should be carefully considered first
⚙️How it works

After menopause, estrogen levels fall sharply because the ovaries no longer produce it in meaningful amounts. The conjugated estrogens in this medication attach to estrogen receptors in tissues throughout the body — including the brain, blood vessels, bones, and vaginal lining — helping to restore the signals estrogen normally provides. This helps reduce hot flashes, prevents bone loss, and restores moisture and tissue health in the vaginal area. Medroxyprogesterone acetate (the progestin) is paired with estrogen because estrogen alone can cause the uterine lining to overgrow; the progestin counteracts this by reducing estrogen-receptor activity in the uterine lining, lowering the risk of endometrial hyperplasia (uterine lining overgrowth) and endometrial cancer.

💊How it's taken

Prempro is taken as one tablet by mouth once daily. Food affects absorption — a high-fat meal can significantly raise the peak blood level of the progestin component — so try to take it consistently either always with food or always without. There is no specific missed-dose instruction in the label; follow your pharmacist's or prescriber's guidance. Your prescriber should periodically reassess whether you still need this therapy, aiming for the lowest effective dose for the shortest duration.

🤒Side effects — in detail

The most commonly reported side effects include:

  • Abdominal pain or stomach discomfort
  • Headache
  • Back pain
  • Nausea and gas (flatulence)
  • Breast pain or tenderness
  • Fatigue or weakness
  • Vaginal discharge (leukorrhea)
  • Painful periods (dysmenorrhea)
  • Depression or mood changes
  • Itching (pruritus)

Seek immediate medical attention for serious symptoms such as sudden chest pain, leg swelling, shortness of breath, sudden vision loss, or signs of stroke (face drooping, arm weakness, speech difficulty) — these could signal a dangerous blood clot or cardiovascular event.

⚠️Warnings & precautions
  • Blood clots, stroke, and heart attack: Studies found increased rates of deep vein thrombosis, pulmonary embolism, stroke, and heart attack in women using estrogen plus progestin. Stop the medication and call 911 if these symptoms occur. Stop at least 4–6 weeks before major surgery or prolonged bed rest.
  • Breast cancer: The WHI study found an increased risk of invasive breast cancer with estrogen plus progestin use. Tumors were detected at a more advanced stage. Get yearly breast exams and mammograms.
  • Probable dementia: Women 65 and older had roughly double the risk of probable dementia in one large study. This medication should not be used to prevent dementia.
  • Ovarian and endometrial cancer: There is a possible increased risk of ovarian cancer. Adding the progestin reduces — but does not eliminate — the risk of endometrial (uterine lining) cancer. Report any unexplained vaginal bleeding promptly.
  • Gallbladder disease: A 2- to 4-fold increased risk of gallbladder disease requiring surgery has been reported with estrogen use.
  • Vision problems: Retinal blood clots have been reported. Discontinue and seek care immediately for sudden vision loss, double vision, or eye bulging.
  • Liver disease: Do not use if you have liver impairment or disease. Stop if jaundice (yellowing of the skin or eyes) develops.
🔀What it interacts with

This medication is processed partly by a liver enzyme called CYP3A4, so drugs that affect that enzyme can change how much estrogen ends up in your bloodstream:

  • St. John's Wort, phenobarbital, carbamazepine, rifampin — these speed up estrogen metabolism, lowering blood levels and possibly making the medication less effective or changing your bleeding pattern
  • Erythromycin, clarithromycin, ketoconazole, itraconazole, ritonavir — these slow estrogen breakdown, raising blood levels and increasing the risk of side effects
  • Grapefruit juice — can raise estrogen levels in the blood, potentially increasing side effects
  • Aminoglutethimide (a cancer treatment) — can significantly reduce the absorption of the medroxyprogesterone component, making it less effective

This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.

📋Before taking it
  • Do not use if you have or have had breast cancer, or any cancer that is fueled by estrogen
  • Do not use if you have or have had blood clots (DVT or pulmonary embolism), stroke, or heart attack
  • Do not use if you have unexplained abnormal vaginal bleeding — the cause must be identified first
  • Do not use if you have liver disease or liver impairment
  • Do not use if you have inherited clotting disorders such as protein C, protein S, or antithrombin deficiency
  • Do not use if you have had a severe allergic reaction (anaphylaxis or angioedema) to Prempro
  • Pregnancy: This medication is not for use during pregnancy
  • Breastfeeding: Estrogens pass into breast milk and can reduce its quantity and quality; discuss with your doctor before use
  • Children: Not indicated for use in children
  • Women over 65: Face higher risks of stroke, invasive breast cancer, and probable dementia — weigh benefits and risks carefully with your doctor
  • Thyroid replacement therapy: Tell your doctor if you take thyroid medication — estrogens can affect thyroid hormone levels and your dose may need monitoring
  • Kidney or liver impairment: The effects of kidney or liver disease on how this medication is processed have not been fully studied; discuss your history with your prescriber
🚑If you take too much

Taking too much of this medication may cause nausea, vomiting, breast tenderness, abdominal pain, drowsiness, and fatigue. Withdrawal bleeding can also occur. If you think you or someone else has taken too much, stop the medication and contact your healthcare provider or poison control right away for guidance on next steps.

🔬Pharmacokinetics — how your body processes it

Both ingredients in Prempro are well absorbed from the gastrointestinal tract after you take it by mouth — the medroxyprogesterone component is released immediately, while the conjugated estrogens are released more slowly over several hours. Eating a high-fat meal can significantly increase peak blood levels of the progestin and modestly affect estrogen levels, so consistency around mealtimes matters. Estrogens circulate in the blood largely bound to proteins (SHBG and albumin), and medroxyprogesterone is about 90% protein-bound as well. Both components are processed in the liver and ultimately cleared from the body, with the estrogen components having half-lives (the time for blood levels to drop by half) ranging from roughly 10 to 37 hours depending on the specific estrogen fraction.

📦How to store it

Store at 20° to 25°C (68° to 77°F); excursions permitted to 15° to 30°C (59° to 86°F) .

📄 Written from Conjugated Estrogens / Medroxyprogesterone’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →

🩺 Pharmacist Counseling Corner

Quick, plain-English answers to the questions patients ask most about Conjugated Estrogens / Medroxyprogesterone — the kind of thing our pharmacy team would talk through with you at the counter.

Why do I need to take a progestin with the estrogen — can't I just take estrogen alone?
If you still have your uterus, estrogen used on its own can cause the uterine lining to grow too thick over time — a condition called endometrial hyperplasia — which can lead to uterine cancer. The medroxyprogesterone in Prempro protects the uterine lining and significantly reduces that risk. Women who have had a hysterectomy (uterus removed) typically don't need the progestin, but since you have a uterus, the combination is the right choice for you.
How long will I need to stay on this medication?
The goal is always to use the lowest effective dose for the shortest time that manages your symptoms. There's no fixed time limit that applies to everyone, but your doctor should check in with you regularly to see whether you still need it. The risks — especially for blood clots, breast cancer, and dementia — are part of the ongoing conversation, and the benefit-risk balance can shift over time, so don't skip those follow-up appointments.
What warning signs should make me stop the medication and call for help right away?
Call 911 immediately for sudden chest pain, shortness of breath, or coughing up blood — those could be a blood clot. Do the same for sudden weakness or numbness on one side, trouble speaking, or a severe sudden headache, which could be a stroke. For sudden vision loss or double vision, stop the medication and see a doctor urgently. Report any new breast lump, unexplained vaginal bleeding, or yellowing of your skin or eyes to your doctor promptly — don't wait.
Does it matter whether I take Prempro with food or on an empty stomach?
It can. Taking Prempro with a high-fat meal roughly doubles the peak blood level of the progestin component. The label doesn't say you must avoid food, but the key is consistency — take it the same way every day, either always with a meal or always without, so your body gets a steady, predictable amount. Your pharmacist or doctor can help you decide which routine works best for you.
I've heard estrogen therapy raises the risk of breast cancer — should I be worried?
It's a real concern worth knowing about. Studies showed that women taking estrogen plus progestin (the combination you're taking) had a modestly increased risk of invasive breast cancer compared to women not taking hormone therapy. That's why yearly breast exams with your doctor and regular mammograms are especially important while you're on this medication. The risk is part of why your doctor should regularly reassess whether you still need the treatment — and why using the lowest effective dose matters.
Are there any common medications or supplements I should avoid while taking Prempro?
Yes — a few things can interfere. St. John's Wort is a common one people don't think of as a 'real' medication, but it can lower estrogen levels in your blood and make Prempro less effective. Antibiotics like erythromycin or clarithromycin, and antifungals like ketoconazole, can have the opposite effect — raising estrogen levels and increasing side effects. Grapefruit juice can also raise estrogen levels. And if you take medication for seizures like carbamazepine or phenobarbital, let your doctor know. Always share your full medication and supplement list, including herbals, with your prescriber and pharmacist.
Is Conjugated Estrogens / Medroxyprogesterone available over the counter?
Conjugated Estrogens / Medroxyprogesterone is dispensed by prescription according to its FDA labeling, so it isn't sold over the counter. Your prescriber and pharmacist will determine if it's appropriate for you.
When was Conjugated Estrogens / Medroxyprogesterone first available?
Conjugated Estrogens / Medroxyprogesterone has been available in the United States since at least 2003, based on FDA approval history (Drugs@FDA) and product marketing records.
Who makes Conjugated Estrogens / Medroxyprogesterone?
Conjugated Estrogens / Medroxyprogesterone is supplied by 3 manufacturers listed in the FDA NDC Directory, including Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc., Pfizer Ireland Pharmaceuticals Unlimited Company, A-S Medication Solutions.

💬 Answers drafted from Conjugated Estrogens / Medroxyprogesterone’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →

🧰 Keep exploring

💊 How Conjugated Estrogens / Medroxyprogesterone comes

Conjugated Estrogens / Medroxyprogesterone is available in 1 form. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.

Tablet

By mouth
Brands Prempro
How this form is used
What it may be used for
  • Prempro is used to treat moderate to severe hot flashes and night sweats (vasomotor symptoms) due to menopause
  • Prempro is used to treat moderate to severe vulvar and vaginal dryness and atrophy due to menopause
  • Prempro is used to help prevent postmenopausal osteoporosis in women at significant risk
Important instructions
  • Prempro is taken as one tablet by mouth once daily
  • Taking Prempro with a high-fat meal can significantly increase the peak blood level of the progestin component — take it consistently the same way each day
  • Use the lowest effective dose for the shortest duration that meets your treatment goals, as directed by your prescriber
  • Your prescriber should periodically re-evaluate whether you still need this treatment
Available strengths 8 strengths
Show 2 more strengths Show fewer strengths
17 FDA-listed product records

📊 Conjugated Estrogens / Medroxyprogesterone across the U.S. market

How Conjugated Estrogens / Medroxyprogesterone appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.

1
Dose forms
3
Manufacturers
2
Brand names
20
FDA-listed product records
2003
First marketed

Also listed with the FDA, not a patient dose form: Kit (3) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.

Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc.75%
Pfizer Ireland Pharmaceuticals Unlimited Company20%
A-S Medication Solutions5%

Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.

📈 How widely Conjugated Estrogens / Medroxyprogesterone is used

A general measure of how commonly Conjugated Estrogens / Medroxyprogesterone is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.

Think of this as a proxy for how widely Conjugated Estrogens / Medroxyprogesterone is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.

48,214
Medicaid prescriptions filled (Q1–Q4 2025)
$14.9M gross Medicaid reimbursement (before mandatory rebates — net cost is lower)

How commonly is Conjugated Estrogens / Medroxyprogesterone prescribed? Of the 1,596 medications we measure, Conjugated Estrogens / Medroxyprogesterone ranks #640 by Medicaid prescriptions — more than 60% of them.

Where Conjugated Estrogens / Medroxyprogesterone ranks among the drugs we measure · Q1–Q4 2025 · neighbors ±5

Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Conjugated Estrogens / Medroxyprogesterone, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 5 of 9 listed Conjugated Estrogens / Medroxyprogesterone NDCs with Medicaid activity.

🔍 Compare Conjugated Estrogens / Medroxyprogesterone products

A representative set of FDA-listed product records for Conjugated Estrogens / Medroxyprogesterone — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)

Showing 20 of 20 products — FDA National Drug Code Directory. See every product, package size and price: browse all 20 Conjugated Estrogens / Medroxyprogesterone NDCs →

🏷️ Sold under these brand names

Prempro Premphase

🏭 Manufacturers & labelers

Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc. 15 Pfizer Ireland Pharmaceuticals Unlimited Company 4 A-S Medication Solutions 1

RxNorm drug class

Conjugated Estrogens / Medroxyprogesterone belongs to the Estrogen class.

Pharmacologic class Estrogen
Drug family (ATC) Natural and semisynthetic estrogens, plain
How it works Estrogen Receptor Agonists

Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.

🔬 Where this comes from

Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.

📄
FDA-filed drug labels (SPL) Uses, dosing, warnings & side effects from SPL records retrieved through openFDA; the linked representative set can be verified on DailyMed. ✓ Linked label effective Apr 28, 2026
🏭
Forms, brands & labelersAggregated from ingredient-matched FDA National Drug Code Directory product records for Conjugated Estrogens / Medroxyprogesterone.
📈
Real-world reportsThe FDA Adverse Event Reporting System (FAERS), served through openFDA.
🚨
Recalls & shortagesopenFDA drug-enforcement reports and the FDA drug-shortage database.
🧾 Clinical label set — FDA-filed SPL labels retained for Conjugated Estrogens / Medroxyprogesterone after exact ingredient or ingredient-combination matching and applicable route/form matching
Clinical labels in scope
1
NDC products indexed
20
Distinct labelers/manufacturers represented
3
Linked representative label
Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc.
Linked label effective
Apr 28, 2026
Composite sections available
24
Linked SPL Set ID
fd0c0836-5d23-2183-da81-9dc7f4287052
Linked SPL Document ID
cce04608-5f9f-434f-b4ab-d5c19847095a
Open the linked representative label on DailyMed ↗

How we combine label and product data

HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 1 FDA-filed SPL label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.

For canonical ingredient pages, bounded product-attributed indication and administration excerpts may be added to the AI evidence, and the generator is instructed to preserve available product, brand, route, and form qualifiers instead of treating one label as universal. Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Wyeth Pharmaceuticals LLC, a subsidiary of Pfizer Inc. is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.

This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.