Reported Reactions

Adverse event reports that FDA received

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Fulvestrant adverse event reports that FDA received

Name type
Generic name
Class
Estrogen receptor antagonist
Also reported as
Fulvestrant Injection

What a report is

A report is not proof that the drug was the cause of the event.

FDA says:

Adverse event reports submitted to FDA do not undergo extensive validation or verification. Therefore, a causal relationship cannot be established between product and reactions listed in a report. While a suspected relationship may exist, it is not medically validated and should not be the sole source of information for clinical decision making or other assumptions about the safety or efficacy of a product. Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.

Source: openFDA, Drug Adverse Event Overview, section "Responsible use of the data". The site read the page on . The data have the reports that FDA received through .

FDA also says:

There is no certainty that the reported event (adverse event or medication error) was actually due to the product. FDA does not require that a causal relationship between a product and event be proven, and reports do not always contain enough detail to properly evaluate an event. The information in these reports has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated.

Source: openFDA, Response of the drug event API (meta.disclaimer). The site read the page on .

Not medical advice. This site counts what was reported to FDA. Questions about a medicine or device belong with a pharmacist or clinician.

Drug reports received through . Device reports have a separate cutoff, 30 Sep 2026. Why a report count is not a rate.

Reports on file

From January 2005 to June 2026, FDA received 11,797 adverse event reports that name Fulvestrant. In these reports the drug is a suspect or interacting product.

In the same period, 5,009 further reports name it only as a concomitant medicine. The counts on this page do not include these reports.

FDA received 1,335 reports in the 12 months to June 2026 and 1,524 in the 12 months before. FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

Of the 1,332,454 drug reports that FDA received in the 12 months to June 2026, 1,335 (0.1%) name Fulvestrant. Reports for female patients were 91.4% of the reports that name Fulvestrant and 52.7% of all drug reports.

The number of people who use the product is not in the data. A count is not a rate. A count of reports is not a count of events or of patients, because one event can have more than one report.

There are many instances of duplicative reports and some reports do not contain all the necessary information.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

Suspect product

FDA records each drug in a report as suspect, concomitant or interacting. This page counts the reports in which Fulvestrant is suspect or interacting. FDA says:

Any number of the drugs may be marked as suspect if thought to be responsible for one or more of the reactions, but that information is not validated.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

Data version

openFDA FAERS release of 29 Oct 2026. Reports received through 30 Jun 2026.

Since the last update

FDA says:

Many factors can influence whether or not an event will be reported, such as the time a product has been marketed and publicity about an event.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

The information in these reports cannot be used to estimate the incidence (occurrence rates) of the events reported.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

The latest update of the FDA data, recorded on , changed no count of this page.

  • In April to June 2026, FDA received 306 reports that name Fulvestrant.
  • In January to March 2026, FDA received 258.
  • In April to June 2025, FDA received 447.

April to June 2026 is the latest closed quarter in the data. A closed quarter is a quarter for which the FDA files have most of the reports.

All updatesFeed of updates (RSS)

Reaction lookup

These are the reaction terms that the reports record, with the number of reports for each term. Type a term or a plain word to find its count.

What this list leaves out

The table lists the 1,145 reaction terms that 5 or more reports record. A term with fewer than 5 reports is not in the table.

The site keeps reaction terms for 11,779 of the 11,797 reports (99.8%).

The reports of the other years are not in the counts.

So a count in the table can be lower than the count of FDA.

The table shows the first 50 of 1,145 terms.

Reaction terms in the reports that name Fulvestrant, most reports first
Reaction term (MedDRA) and plain meaningReportsShare of the 11,797 reports
Malignant neoplasm progression2,42220.5%
Metastases to bone1,28710.9%
Neutropenialow neutrophils, a type of white blood cell1,26110.7%
Fatiguetiredness1,22310.4%
Nauseafeeling sick1,1529.8%
Metastases to liver1,0609%
Breast cancer metastatic1,0558.9%
Diarrhoealoose or frequent stools8787.4%
Deaththe patient died; cause not stated by this term8747.4%
Drug ineffectivethe medicine did not work as expected6685.7%
Vomitingbeing sick6475.5%
Dyspnoeashortness of breath6445.5%
Painpain, site not specified6245.3%
Anaemialow red blood cells6225.3%
Astheniaweakness or lack of energy6195.2%
Breast cancer5664.8%
Off label useused for a purpose or in a way not on the label5214.4%
Rashskin rash5104.3%
Disease progressionthe disease advanced5064.3%
Arthralgiajoint pain5034.3%
Neoplasm progression4994.2%
Decreased appetitereduced appetite4964.2%
Metastases to lung4914.2%
Malaisegeneral feeling of being unwell4844.1%
Thrombocytopenialow platelets4633.9%
General physical health deteriorationgeneral decline in health4603.9%
Cough4483.8%
Pyrexiafever4293.6%
Leukopenialow white blood cells3933.3%
Dizzinesslight-headedness or unsteadiness3903.3%
Weight decreasedweight loss3873.3%
Headachehead pain3713.1%
White blood cell count decreasedlow white cell count3703.1%
Alopeciahair loss3613.1%
Pleural effusionfluid around the lung3573%
Pruritusitching3563%
Pain in extremitypain in an arm or leg3362.8%
Back pain3352.8%
Hyperglycaemiahigh blood sugar3252.8%
Drug intolerancethe medicine was not tolerated3082.6%
Constipation2802.4%
Abdominal painstomach or belly pain2632.2%
Metastases to lymph nodes2632.2%
Neutrophil count decreased2562.2%
Tumour marker increased2522.1%
Haemoglobin decreasedlow haemoglobin2492.1%
Platelet count decreasedlow platelet count2412%
Covid-19COVID-19 infection2352%
Decreased immune responsiveness2352%
Hypertensionhigh blood pressure2332%

Download all 1,145 terms of Fulvestrant (CSV)

The counts add to more than 11,797 reports, because one report can record more than one term. FDA says:

No individual drug is connected to any individual reaction. When a report lists multiple drugs and multiple reactions, there is no way to conclude from the data therein that a given drug is responsible for a given reaction.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

The CSV file has the same rows and the same limits. Its last row is a note that says so.

MedDRA term

The person who codes a report selects the preferred term that agrees best with the description of the reporter. The words under a term are the plain meaning that this site gives.

Not the label

The FDA-approved label of a product lists its adverse reactions. See the official pages at the end of this page.

Same ingredient, other names

Reporters write a brand name or a generic name. Each name has its own page and its own count.

Names of Fulvestrant with a page, in the order generic names, brand names, names as reported
NameName typeReports
Fulvestrant (this page)Generic name11,797
FaslodexBrand name8,884

Sum of the separately reported names: 20,681. A report that names two of these names is in the sum two times. The sum is not the number of reports for the ingredient.

FDA says:

Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

Importantly, the AEMS data by themselves are not an indicator of the safety profile of the drug or biologic.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

Outcomes by year

The table gives the outcomes that the reporters gave, in the terms of FDA.

Outcomes in the reports that name Fulvestrant, by the year of the openFDA file that holds the report

The table continues to the right.

Year of the openFDA fileReportsSeriousDeathLife-threateningHospitalization (initial or prolonged)Disability or Permanent DamageCongenital Anomaly/Birth DefectOther Serious (Important Medical Events)Not serious
2005222121000
2006000000000
2007220210000
2008151510400110
2009660130020
2010331020020
201134341821420100
201216165051070
2013212070700131
2014191820120071
201587759325005712
201615012126735208529
2017243212454392016331
201838635034101004028536
201963158474161349047747
20201,3451,28819058334811,06757
20211,3211,2652393640023297356
20221,2521,168250592917087984
20231,9821,904405754881201,58878
20241,3751,29425377395801,09881
20252,1002,0293031266411511,71371
20268077651165625420062342

An outcome in a report is not proof that the drug was the cause. The reporter gives the outcome, and FDA does not verify it. FDA says:

The information in these reports has not been scientifically or otherwise verified as to a cause and effect relationship and cannot be used to estimate the incidence of these events.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

The six headings with the names of FDA are the outcome terms of FDA. A report can have more than one outcome. The columns Serious and Not serious are the two values of the openFDA field serious. For the value serious, openFDA gives this description:

The adverse event resulted in death, a life threatening condition, hospitalization, disability, congenital anomaly, or other serious condition

Source: openFDA, Drug adverse event fields (YAML reference). The site read the page on .

The year is the year of the openFDA file that holds the latest version of the report. It is not always the year in which FDA first received the report. The chart of the next section uses the year of first receipt. The latest year is not complete.

Reports by year and month

Reports that name Fulvestrant, by the year in which FDA received them
02,5005,0002005200920122015201820212024

The column of 2026 has an outline, because the year is not complete. It has the reports that FDA received through June 2026 only.

Show the figures of the chart as a table
Reports that name Fulvestrant, by the year in which FDA received them
YearReports
20052
20072
200816
20095
20105
201136
201221
201319
201425
201596
2016160
2017274
2018417
2019784
20201,551
20211,379
20221,251
20232,179
20241,394
20251,617
2026564
Reports that name Fulvestrant, by month, five years to June 2026
025050020222023202420252026

FDA releases FAERS data every quarter, so the newest months are not complete. They grow in later releases.

Why a count moves

A count moves for many reasons. The guide gives FDA's words about them.

Patients and reporters

Age of the patient in the reports that name Fulvestrant
AgeReportsShareShare as a bar
Under 21under 0.1%
2 to 1100%
12 to 173under 0.1%
18 to 446135.2%
45 to 643,46129.3%
65 to 741,76014.9%
75 and over1,1599.8%
Age not given4,80040.7%
Sex of the patient in the reports that name Fulvestrant
SexReportsShareShare as a bar
Female10,78891.4%
Male1000.8%
Unknown or not given9097.7%
Type of reporter in the reports that name Fulvestrant
ReporterReportsShareShare as a bar
Physician5,88249.9%
Pharmacist3743.2%
Other health professional2,93024.8%
Lawyer1under 0.1%
Consumer or non-health professional2,38820.2%
Not given2221.9%

Age and sex are as the report gives them. The reporter is the primary source in the report. 13.5% of the reports give the United States as the country.

Reason for use

Reason for use (indication) that the reports of Fulvestrant record
Indication as recorded (MedDRA)ReportsShare
Breast cancer metastatic3,11126.4%
Breast cancer2,23018.9%
Hormone receptor positive her2 negative breast cancer7776.6%
Breast cancer female2722.3%
Hormone receptor positive breast cancer1971.7%
Invasive ductal breast carcinoma1131%

The reporter fills in the indication, and the field is often empty. Each share is of all 11,797 reports.

Drugs in the same reports

Other drugs that the reports of Fulvestrant name, in any role, in order of name
DrugReports that name the two
Capecitabine1,157
Denosumab915
Exemestane998
Ibrance1,285
Kisqali2,610
Letrozole2,229
Paclitaxel960
Palbociclib2,307
Ribociclib1,270
Tamoxifen948

The table has the 10 drug names that these reports name most. Two names in one report says only that the report recorded the two. It says nothing about the part of a product in the event.

FDA says:

Additionally, it is important to remember that adverse event reports represent a small percentage of total usage numbers of a product. Common products may have a higher number of adverse events due to the higher total number of people using the product.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

Importantly, the AEMS data by themselves are not an indicator of the safety profile of the drug or biologic.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

Pages near this one

These links are for navigation. No count selected them. The class page lists each drug of the class.

Official pages

The site checked these addresses on . The links open in a new tab.

Cite this page

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Reported Reactions. Fulvestrant: adverse event reports that FDA received. https://reportedreactions.com/drug/fulvestrant/ Source: U.S. Food and Drug Administration, openFDA Drug Adverse Event (FAERS) files, release of . Reports received through .

Where the data come from

The counts come from the openFDA Drug Adverse Event (FAERS) bulk files, release of 29 Oct 2026. The files have the reports that FDA received through 30 Jun 2026. A drug name is the name on the report. The site matches it to a brand name or a generic name of the National Drug Code Directory of 2 Nov 2026. A class is the pharmacologic class (EPC) of the FDA label.

A report is in the count when it names Fulvestrant as a suspect or interacting product. The 5,009 reports that name it only as a concomitant medicine are not in the count. The site does not publish a report narrative, a lot number, a detail of a patient or the identity of a reporter. The record of FDA is the authority. See how the site counts reports, the data sources and the corrections page.

Questions

Do these reports show that Fulvestrant was responsible for the reactions?

No. FDA says:

For any given report, there is no certainty that a suspected drug caused the event.

Source: FDA, FDA Adverse Event Monitoring System (AEMS) Public Dashboard. Content current as of . The site read the page on .

A reaction can relate to the condition that the drug treats, to other medicines, or to something else.

Is this the list of reactions on the label of Fulvestrant?

No. It is a count of what people reported to FDA: 11,797 reports from January 2005 to June 2026. The FDA-approved label of a product lists its adverse reactions. The official pages at the end of this page link to the labels.

Who sent these reports?

Physician (49.9%), other health professional (24.8%) and consumer or non-health professional (20.2%). These are the types of reporter for the reports that name this drug.

If a manufacturer receives an adverse event report, it is normally required to send the report to FDA.

Source: openFDA, Drug Adverse Event Overview. The site read the page on .

How does a person report an adverse event?

FDA runs MedWatch, a program that takes voluntary reports from health professionals, patients and consumers. The guide on how to report has the links.