Fulvestrant: adverse event reports filed with FDA

11,797

reports as suspect product

0.1% of all reports · about 549 a year

1,335

reports, 12 months to June 2026

1,524 in the 12 months before

94.7%

marked serious by the reporter

72.9% across the class

16.8%

record death among outcomes, as reported

1,980 reports · not verified by FDA

Reports by month, five years

Reports by the month FDA received them. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

By year received

2026 covers reports received through June 2026 only.

Reactions recorded in the reports

share of Fulvestrant reports recording the termmedian drug in estrogen receptor antagonist

1. Malignant neoplasm progression20.5%2,422
2. Metastases to bone10.9%1,287
3. Neutropenialow neutrophils, a type of white blood cell10.7%1,261
4. Fatiguetiredness10.4%1,223
5. Nauseafeeling sick9.8%1,152
6. Metastases to liver9%1,060
7. Breast cancer metastatic8.9%1,055
8. Diarrhoealoose or frequent stools7.4%878
9. Deaththe patient died; cause not stated by this term7.4%874
10. Drug ineffectivethe medicine did not work as expected5.7%668
11. Vomitingbeing sick5.5%647
12. Dyspnoeashortness of breath5.5%644
13. Painpain, site not specified5.3%624
14. Anaemialow red blood cells5.3%622
15. Astheniaweakness or lack of energy5.2%619
16. Breast cancerbreast cancer4.8%566
17. Off label useused for a purpose or in a way not on the label4.4%521
18. Rashskin rash4.3%510
19. Disease progressionthe disease advanced4.3%506
20. Arthralgiajoint pain4.3%503
21. Neoplasm progression4.2%499
22. Decreased appetitereduced appetite4.2%496
23. Metastases to lung4.2%491
24. Malaisegeneral feeling of being unwell4.1%484
25. Thrombocytopenialow platelets3.9%463
26. General physical health deteriorationgeneral decline in health3.9%460
27. Coughcough3.8%448
28. Pyrexiafever3.6%429
29. Leukopenialow white blood cells3.3%393
30. Dizzinesslight-headedness or unsteadiness3.3%390

Top 30 of 1,889 MedDRA preferred terms recorded across these reports, with a plain-language gloss where one is available. One report can record several terms. The hollow bar is the median share across the 3 drugs in the estrogen receptor antagonist class; it describes the reports, not the patients. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Outcomes recorded

Outcome flags as the reporter set them; a report can carry several, and "other serious" is FDA's own category for serious reports outside the named outcomes. Grey bar: all 27,672 reports in the class. FDA has not verified any outcome and states that the reports "cannot be used to estimate the incidence of these events."

Patients and reporters

Age and sex as stated in the report; the reporter's qualification is the primary source recorded by FDA. 13.5% of reports give the United States as the country of the event or reporter.

Reason for use recorded

The indication field is filled in by the reporter and is often blank; shares are of all 11,797 reports.

Drugs most often listed in the same reports

Other products listed in reports where Fulvestrant is a suspect product, whatever their own role. Co-listing means the two were recorded together; it says nothing about either product's part in the event. Only the 2,500 most-reported names are counted here.

In context

Shares are of reports, not of patients treated. The number of people taking a product is not in the data, so none of these figures is a rate, and differences between columns reflect who takes a product, who reports and how long it has been sold. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Other drugs in the estrogen receptor antagonist class

Ordered by report count for navigation only. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic." A brand and its generic are separate rows because reporters name them separately.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. A report counts here when it lists Fulvestrant as a suspect or interacting product; reports listing it only as a concomitant medication (5,009) are excluded. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.