Pharmacologic class (EPC) · 25 drug pages

Estrogen: adverse event reports filed with FDA

127,523 reports list a drug in this class as a suspect or interacting product, 2004–2026.

Read first · FDA's statement on these data

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. openFDA, FDA

FDA adds: "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 "cannot be used to estimate the incidence of these events."

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.

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

127,523
reports across the class: 0.6% of all reports; 5,726
reports, 12 months to June 2026: 4,342 in the 12 months before; 57.2%
marked serious by the reporter: 57.4% across all reports; 25
drugs with a page: brand and generic names counted separately

Estrogen is a pharmacologic class (an FDA Established Pharmacologic Class) with 25 drug pages on this site. Together those drugs are listed as a suspect or interacting product in 127,523 adverse event reports received by FDA, 0.6% of the database, from January 2004 to June 2026.

5,726 reports arrived in the 12 months to June 2026, up 32% from 4,342 in the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. 57.2% of the class's reports are marked serious, 1.7% record death among the outcomes and 10.5% record hospitalisation, as reported.

Across the class the reactions recorded most often are breast cancer (16%), breast cancer female (14.4%) and product adhesion issue (6.6%). The class median share shown beside each term is the middle value across the member drugs; it is the comparison used on every drug page in this class.

The members table is 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."

Drugs in the class

Drug	Name type	Reports	Latest 12 months	Marked serious	Top term recorded
PremarinConjugated estrogens	brand	34,401	158	77.8%	Breast cancer
PremproConjugated estrogens and medroxyprogesterone acetate	brand	19,832	36	90.4%	Breast cancer
NuvaringEtonogestrel and ethinyl estradiol	brand	18,643	55	49.2%	Pulmonary embolism
Estradiol	generic	15,479	2,777	43%	Breast cancer female
Estradiol Transdermal SystemEstradiol	brand	5,989	1,308	3.2%	Product adhesion issue
EstraceEstradiol	brand	4,649	25	58.9%	Breast cancer
EstringEstradiol	brand	3,813	115	30.5%	Drug ineffective
CombiPatch (estradiol/norethindrone acetate transdermal system)Estradiol/norethindrone acetate transdermal system	brand	3,608	384	19.5%	Product adhesion issue
ClimaraEstradiol	brand	3,146	37	25.9%	Product adhesion issue
MinivelleEstradiol	brand	2,823	33	4%	No adverse event
Climara ProEstradiol and levonorgestrel	brand	1,949	115	11%	Product adhesion issue
XulaneNorelgestromin and ethinyl estradiol	brand	1,537	65	10.3%	Product adhesion issue
Vivelle-DotEstradiol	brand	1,488	62	32.1%	Drug ineffective
EstroGelEstradiol	brand	1,312	94	74.9%	Drug ineffective
Conjugated estrogens	generic	1,167	12	98.7%	Breast cancer female
TwirlaLevonorgestrel/ethinyl estradiol	brand	1,014	96	2.1%	Product adhesion issue
ActivellaEstradiol/norethindrone acetate	brand	875	4	88%	Breast cancer
VagifemEstradiol	brand	865	33	82.3%	Breast cancer female
DuaveeConjugated estrogens/bazedoxifene	brand	845	4	20.6%	Drug ineffective
EstrogensEstradiol, folliculinum, oophorinum (suis)	brand	738	57	90.1%	Breast cancer
Estradiol VaginalEstradiol	brand	727	97	4.7%	Product quality issue
EluRyngEtonogestrel and ethinyl estradiol	brand	722	75	9.4%	Device breakage
Estrogen	generic	673	3	90.6%	Breast cancer
PremphaseConjugated estrogens and medroxyprogesterone acetate	brand	627	0	89.8%	Breast cancer female
FemringEstradiol acetate	brand	601	81	14.3%	Drug ineffective

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."

Reports by month, five years

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Reactions recorded across the class

share of class reports recording the termmedian drug in the class

Breast cancerbreast cancer16%20,403
Breast cancer female14.4%18,332
Product adhesion issue6.6%8,371
Drug ineffectivethe medicine did not work as expected5.6%7,155
Off label useused for a purpose or in a way not on the label4.1%5,270
Pulmonary embolisma blood clot in the lung3.8%4,792
Hot flusha hot flush3.7%4,667
No adverse eventno adverse event was reported3.4%4,310
Breast cancer metastatic2.8%3,553
Deep vein thrombosisa blood clot in a deep vein2.8%3,533
Product quality issuea problem with the product itself2.7%3,503
Headachehead pain2.7%3,419
Wrong technique in product usage processthe product was used in the wrong way2.4%3,057
Inappropriate schedule of drug administrationthe medicine was taken at the wrong times2%2,580
Application site pruritusitching where the product was applied1.8%2,353
Application site erythemaredness where the product was applied1.8%2,315
Anxietyanxiety1.8%2,297
Nauseafeeling sick1.7%2,229
Painpain, site not specified1.6%2,028
Depressionlow mood1.6%2,020
Vaginal haemorrhagevaginal bleeding1.6%2,012
Insomniadifficulty sleeping1.5%1,973
Feeling abnormalfeeling odd or not right1.4%1,802
Application site rash1.4%1,773
Fatiguetiredness1.4%1,765

Solid bar: share of all class reports. Hollow bar: the median share across the 25 member drugs, the reference used on each member's page. One report can record several terms.

Outcomes, patients and reporters

Outcomes recorded

Death1.7%2,171

Life-threatening1.2%1,578

Hospitalisation (initial or prolonged)10.5%13,354

Disability2.1%2,644

Congenital anomaly0.1%110

Other serious52.8%67,349

Not serious42.8%54,620

Patient age

Under 20.1%76

2 to 110.1%83

12 to 170.4%514

18 to 449%11,496

45 to 6420.6%26,308

65 to 746.8%8,624

75 and over3.2%4,116

Age not given59.8%76,306

Who reported

Physician7.4%9,493

Pharmacist3.7%4,669

Other health professional5.9%7,524

Lawyer17.5%22,282

Consumer or non-health professional49%62,532

Not given16.5%21,023

Grey bar: all 20,646,523 reports in the database. Outcome flags are as the reporter set them and are not verified by FDA.

Questions about Estrogen reports

Which drugs are in the Estrogen class on this site?

Premarin, Prempro, Nuvaring, Estradiol, Estradiol Transdermal System and Estrace and 19 more. Class membership comes from the pharmacologic class (EPC) on the drug's FDA label.

How many reports does the class have?

127,523 reports through June 2026, 5,726 of them in the latest 12 months. A report listing two drugs of the class counts once for each.

What reactions are recorded most often?

breast cancer (16%), breast cancer female (14.4%), product adhesion issue (6.6%), drug ineffective (5.6%) and off label use (4.1%).

Can the members table be used to rank the drugs?

No. 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." Drugs differ in how many people take them, in the conditions they treat, in time on the market and in how diligently reports are collected.

How do I report an adverse event?

Through FDA MedWatch (Form FDA 3500, or 1-800-FDA-1088) or to the manufacturer. See the guide on how to report.

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 class is the Established Pharmacologic Class most often attached to a drug's reports by openFDA's label harmonisation, or from the NDC Directory where reports carry none. 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.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.