Elacestrant
Elacestrant is an estrogen receptor antagonist used to treat a specific type of advanced or metastatic breast cancer in postmenopausal women and adult men.
🧬 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 →
📖 Elacestrant: Patient Information Guide
A plain-language walkthrough of Elacestrant — 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▾
Elacestrant is approved for one specific type of advanced breast cancer. Here's what the evidence supports:
- Orserdu is approved to treat postmenopausal women or adult men with estrogen receptor (ER)-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer, where the cancer has continued to grow after at least one prior endocrine (hormone-based) therapy
- Before starting Orserdu, an FDA-authorized test must confirm that the cancer carries an ESR1 mutation — this is detected from a blood (plasma) sample
- This is not a general breast cancer treatment; it targets a specific molecular profile that your oncologist will verify through testing
⚙️How it works▾
Elacestrant is an estrogen receptor antagonist — it works by attaching to estrogen receptor-alpha (ERα), a protein found on the surface of many breast cancer cells. Instead of just blocking estrogen from binding, elacestrant also triggers the breakdown of the ERα protein itself through a process called proteasomal degradation. Without this receptor, cancer cells lose a key signal that drives their growth.
Importantly, elacestrant has shown activity against cancers that have become resistant to other hormonal therapies — including those resistant to fulvestrant and CDK4/6 inhibitors (drugs that block proteins involved in cell division), and those with ESR1 gene mutations that often develop after prior endocrine treatments.
💊How it's taken▾
Orserdu is taken as a tablet by mouth, once daily, with food. Eating with the dose is important — it helps reduce nausea and vomiting, and it also increases how much of the drug your body absorbs. Swallow the tablet whole; do not chew, crush, or split it.
- Take it at roughly the same time each day
- If you miss a dose by more than 6 hours, or vomit after taking it, skip that dose — take your next dose the following day as usual; do not double up
- If side effects become difficult to tolerate, your doctor may reduce your dose or pause treatment temporarily — do not adjust the dose on your own
- If you have moderate liver impairment, your dose will be lower; Orserdu should be avoided in severe liver impairment
🤒Side effects — in detail▾
The most common side effects seen in clinical trials (occurring in more than 10% of patients) included:
- Musculoskeletal pain — muscle, joint, or bone pain (the most common, affecting about 4 in 10 patients)
- Nausea (about 1 in 3 patients) and vomiting
- Fatigue
- Decreased appetite
- Diarrhea and constipation
- Headache
- Abdominal pain
- Hot flushes
- Indigestion (dyspepsia)
- Lab changes: elevated cholesterol, triglycerides, and liver enzymes; low hemoglobin (anemia) and low sodium
Serious reactions — including severe musculoskeletal pain or severe nausea leading to stopping treatment — occurred in a small number of patients. Contact your doctor promptly if side effects feel unmanageable or worsen quickly.
⚠️Warnings & precautions▾
- Dyslipidemia (high cholesterol and triglycerides): Elevated cholesterol occurred in about 30% of patients and elevated triglycerides in about 27%. These changes are usually monitored through routine blood tests before and during treatment. Rarely, they can reach serious (Grade 3–4) levels that require medical management.
- Embryo-fetal toxicity (harm to an unborn baby): Elacestrant can cause fetal death and birth defects based on animal studies and its mechanism of action. Women who could become pregnant must have a negative pregnancy test before starting, use effective contraception throughout treatment and for 1 week after the last dose, and must not breastfeed during this time. Male patients with female partners who could become pregnant should also use contraception during treatment and for 1 week after stopping. Elacestrant may also impair fertility in both males and females.
🔀What it interacts with▾
Elacestrant is processed mainly by a liver enzyme called CYP3A4, and it also affects how some other drugs are handled. Key interactions to know:
- Strong or moderate CYP3A4 inhibitors (e.g., itraconazole, fluconazole, certain antifungals): Raise elacestrant levels significantly — avoid combining these with Orserdu
- Strong or moderate CYP3A4 inducers (e.g., rifampin, efavirenz, certain antibiotics and antivirals): Dramatically lower elacestrant levels, potentially making it ineffective — avoid these as well
- P-gp substrates (e.g., digoxin): Elacestrant can increase blood levels of these drugs — your doctor may need to adjust their doses
- BCRP substrates (e.g., rosuvastatin): Elacestrant can increase blood levels of these drugs — dose adjustments may be needed
- Drugs such as omeprazole (acid reducers) and warfarin (a blood thinner) did not show significant interactions in clinical studies
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▾
- Pregnancy: Do not take Orserdu if you are pregnant — it can cause serious harm or death to a fetus. A pregnancy test is required before starting.
- Breastfeeding: Do not breastfeed while taking Orserdu or for 1 week after your last dose.
- Contraception: Both women of childbearing potential and men with female partners who could become pregnant must use effective contraception during treatment and for 1 week after stopping.
- Fertility: This drug may impair fertility in both men and women — discuss this with your doctor before starting if fertility is a concern.
- Liver disease: Dose adjustment is required for moderate liver impairment; Orserdu should be avoided entirely in severe liver impairment. Mild liver impairment does not require a dose change.
- Children: Safety and effectiveness in pediatric patients have not been established.
- Older adults: No significant differences in safety or effectiveness were seen in patients 65 years and older compared to younger patients in clinical trials.
- Other medications: Tell your doctor and pharmacist about everything you take — several commonly used drugs (antifungals, antibiotics, antivirals, certain heart and cholesterol medications) can interact with elacestrant.
📡Pharmacodynamics — effects in the body▾
Elacestrant does not meaningfully affect the heart's electrical rhythm — specifically, it does not cause a clinically significant increase in the QTc interval (the part of the heart's rhythm measured on an ECG) at the approved dose. The full relationship between elacestrant blood levels and its effects on tumor response has not yet been completely characterized.
🔬Pharmacokinetics — how your body processes it▾
After you take Orserdu by mouth, peak blood levels are reached within 1 to 4 hours. Taking it with a high-fat meal increases absorption noticeably, which is why food is recommended. The drug stays in your system for a while — its half-life (the time it takes for the body to clear half the drug) is 30 to 50 hours, and steady levels in the blood are reached by about day 6 of daily dosing.
Elacestrant is broken down primarily by a liver enzyme called CYP3A4, and most of it leaves the body through the stool (about 82%), with a small amount exiting in the urine. Age, sex, and body weight do not significantly affect how the drug behaves, but moderate or severe liver disease does increase drug exposure, which is why dose adjustments are needed in those situations.
📦How to store it▾
Store at 20°C to 25°C (68°F to 77°F).
📄 Written from Elacestrant’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 Elacestrant — the kind of thing our pharmacy team would talk through with you at the counter.
What exactly is Orserdu, and why did my doctor choose it for me? ▾
Do I have to take it with food? What if I forget? ▾
What side effects should I expect, and which ones should make me call my doctor? ▾
Are there any medications I should avoid while taking this? ▾
Is it safe to get pregnant or breastfeed while on Orserdu? ▾
Do I need to swallow the tablet whole, or can I crush it? ▾
Is Elacestrant available over the counter? ▾
When was Elacestrant first available? ▾
Who makes Elacestrant? ▾
💬 Answers drafted from Elacestrant’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 Elacestrant comes
Elacestrant 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
How this form is used
- Orserdu tablets are used to treat postmenopausal women or adult men with ER-positive, HER2-negative, ESR1-mutated advanced or metastatic breast cancer that has progressed after at least one prior endocrine therapy
- Orserdu is only appropriate when an FDA-authorized test has confirmed the presence of ESR1 mutation(s) in a plasma specimen
- Orserdu tablets are taken orally once daily with food to help reduce nausea and vomiting
- Swallow Orserdu tablets whole — do not chew, crush, or split them, and do not use tablets that appear broken, cracked, or damaged
- Take Orserdu at approximately the same time each day; if a dose is missed by more than 6 hours or vomiting occurs, skip that dose and resume the next day
- Orserdu should be continued until disease progression or unacceptable side effects occur, as directed by your prescriber
📊 Elacestrant across the U.S. market
How Elacestrant 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.
Also listed with the FDA, not a patient dose form: Powder (1) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Elacestrant is used
A general measure of how commonly Elacestrant 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 Elacestrant 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.
How commonly is Elacestrant prescribed? Of the 1,596 medications we measure, Elacestrant ranks #1,293 by Medicaid prescriptions — more than 19% of them.
Utilization by Elacestrant product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
Other Elacestrant products — combination packs and listings not yet matched to a specific clinical product (kept visible so every prescription is accounted for)
Summed across the 1 of 4 listed NDC products with Medicaid activity.
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Elacestrant, 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 1 of 4 listed Elacestrant NDCs with Medicaid activity.
🔍 Compare Elacestrant products
A representative set of FDA-listed product records for Elacestrant — 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.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Tablet | ||||
| 86 mg | — | Catalent Pharma Solutions, LLC | DRUG FOR FURTHER PROCESSING | View NDC → |
| 345 mg | — | Catalent Pharma Solutions, LLC | DRUG FOR FURTHER PROCESSING | View NDC → |
| 86 mg | Oral | Stemline Therapeutics, Inc. × 3 listings | NDA | View NDC → |
| 345 mg | Oral | Stemline Therapeutics, Inc. × 3 listings | NDA | View NDC → |
| 💊Bulk drug substance | ||||
| 1 kg/kg | — | Granules India Limited | BULK INGREDIENT | View NDC → |
Showing 9 of 9 products — FDA National Drug Code Directory. See every product, package size and price: browse all 9 Elacestrant NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Elacestrant — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Elacestrant in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Elacestrant went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 2628469 1 dose form · 2 strengths
-
Dose form (SCDF) Oral Tablet RxCUI 2628477In current FDA listingsClinical drug / strength (SCD) 86 MGRxCUI 2628478345 MGRxCUI 2628487
Look up RxCUI 2628469 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Elacestrant is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
RxNorm drug class
Elacestrant belongs to the Estrogen Receptor Antagonist class.
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.
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. Stemline Therapeutics, 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.