Drugs by active ingredient › Estradiol + Trenbolone Acetate
Drug · combination of 2 active ingredients
Estradiol + Trenbolone Acetate: adverse event reports
All products with this ingredient combination · 5 FDA-approved applications in the Green Book
- Mostly cattle reports
- Subcutaneous route most often
- Brands masked by FDA
Between January 1995 and December 2025 FDA received 267 adverse event reports listing a drug with the combination estradiol and trenbolone acetate as the recorded active ingredients. The Green Book lists 5 FDA-approved applications with exactly this combination.
openFDA masks the brand and manufacturer in every report, so these figures describe the ingredient combination across all products and cannot be attributed to a brand.
In the 12 months to March 2026, 16 reports named it, up 700% from 2 in the 12 months before. Recent months are provisional: fDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Over its whole reporting history that is about 9 reports a year and 0% of all 1,357,245 reports (0.5% of all cattle reports). How many animals received it is not published, so a count says nothing about how often a problem occurs per dose.
Reporters most often listed death (22.5%), increased sexual interest (14.2%) and underfilling, Package (11.2%). A report can list several signs, so shares add to more than 100%; 152 different terms appear across these reports. Death appears in 22.5% of these reports, about the same share as in the pooled reports for every drug containing trenbolone acetate (19.8%).
61% of reports concern cattle. Not every report describes illness: 36.7% as product or packaging defects. Of reports that state seriousness, 69.1% were classed as serious, and 27.7% of all reports record a death or euthanasia as an outcome, as reported. FDA has not necessarily determined whether any drug played a part.
Monthly reports by species, five years
Reports by the month FDA received them. Each panel has its own scale; the peak month is printed at the top right. The newest months are incomplete because FDA posts reports with a delay of three to six months.
Reports by year received
2025 covers reports received through March 2026 only.
Signs listed in reports
share of estradiol + trenbolone acetate reports listing the termall drugs containing trenbolone acetateall cattle reports
- Death22.5%60
- Increased sexual interest14.2%38
- Underfilling, Package[a product quality report, not a sign in an animal]11.2%30
- Implant, Abnormal10.9%29
- Color, Abnormal[a product quality report, not a sign in an animal]10.1%27
- Anaphylaxis[sudden severe allergic-type reaction]7.5%20
- Respiratory tract disorder NOS[NOS: not otherwise specified]7.5%20
- Dispenser, Abnormal[a product quality report, not a sign in an animal]6.7%18
- Behavioural disorder NOS[behaviour change, type not specified]5.6%15
- Digestive tract disorder NOS[digestive problem, type not specified]5.2%14
- Lack of efficacy - NOS[the product did not have the expected effect]5.2%14
- Pneumonia[lung infection or inflammation]4.5%12
- Death by euthanasia[the animal was euthanized]3.4%9
- Dyspnoea[difficulty breathing]3.4%9
- Lameness3%8
- Bronchopneumonia2.6%7
- Facial oedema[swollen face]2.6%7
- Found dead2.6%7
- Lung oedema2.6%7
- Ruminal bloat2.6%7
- Bloated2.2%6
- Trauma NOS[NOS: not otherwise specified]2.2%6
- Caps, Abnormal[a product quality report, not a sign in an animal]1.9%5
- Containers, Abnormal[a product quality report, not a sign in an animal]1.9%5
- Ineffective, weight inc[legacy FDA term: the product did not have the expected effect (weight inc)]1.9%5
- Injection site abscess[abscess where the injection was given]1.9%5
- Liver abscess1.9%5
- Product Defect, General[a product quality report, not a sign in an animal]1.9%5
- Recumbency[lying down and unable or unwilling to rise]1.9%5
Top 30 of 152 coded terms (VeDDRA, the veterinary reporting dictionary; plain-language gloss in brackets). One report can list several terms. The ticks show how often the same term appears in a wider pool of reports; they describe the reports, and FDA cautions that such figures cannot be used to estimate risk or to compare one product with another. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand.
Outcomes and report types
Outcome recorded in the report
What kind of report it was
Coloured bar: reports naming estradiol + trenbolone acetate. Grey bar: all 1,357,245 reports in the database. Outcomes are the status at the time of the last report, as stated by the reporter; a report covering several animals can carry more than one outcome. FDA has not necessarily determined whether any drug played a part in any outcome.
Species and breeds in the reports
Single-breed animals
Breed shares follow how common each breed is. Crossbred animals and reports with no breed stay in the species figure only.
Age, weight and route
Age of the animal
Weight of the animal
Route of administration stated in reports: subcutaneous (86), other (13), topical (5), intramuscular (2), oral (2), parenteral (1).
In context
| Measure | Estradiol + Trenbolone Acetate | All drugs containing trenbolone acetate | All cattle reports | All reports |
|---|---|---|---|---|
| Reports | 267 | 642 | 31,229 | 1,357,245 |
| Share of that pool's reports naming this drug | — | 41.6% | 0.5% | 0% |
| Classed serious, of reports stating it | 69.1% | 44% | 58.4% | 38.6% |
| Death or euthanasia recorded, per 1,000 reports | 277.2 | 265 | 368 | 63.8 |
| Filed as lack of expected effectiveness (wholly or partly) | 6.4% | — | — | 23% |
| Top term, share of reports | Death 22.5% | 19.8% | 29.4% | — |
The trenbolone acetate pool is every report naming trenbolone acetate alone or in any combination; this combination accounts for 41.6% of it. Shares are of reports, not of animals treated. The number of doses sold is not public, so none of these figures is a rate of occurrence, and differences between columns reflect which animals receive a drug and who reports as much as anything else.
Other ingredient sets sharing an ingredient
| Active ingredients | Reports | Latest 12 months |
|---|---|---|
| Estradiol | 428 | 11 |
| Estradiol Benzoate + Trenbolone Acetate | 342 | 21 |
| Estradiol + Tylosin Tartrate | 74 | 0 |
| Estradiol + Testosterone | 47 | 0 |
| Estradiol + Norgestomet | 44 | 0 |
| Estradiol + Trenbolone Acetate + Tylosin Tartrate | 31 | 4 |
Listed for navigation, ordered by report count. FDA states that these data "cannot be used to estimate the risk associated with the product or compare one drug or device product with another": drugs differ in formulation, in the animals they are given to, in sales volume and in years on the market. A report's ingredient field can be incomplete, so reports about one product may sit under more than one set.
FDA-approved products containing this combination (Green Book)
Reference information, not report statistics. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand. The list below is the FDA Green Book as of 1 Oct 2026; nothing on this page says which of these products, if any, a report concerned.
| Trade name | Active ingredients | Sponsor | Approved for | Application |
|---|---|---|---|---|
| Revalor-G; Revalor-IS; Revalor-S | Estradiol, Trenbolone Acetate | Intervet, Inc. | Cattle | NADA 140-897 |
| Revalor-200; Revalor-H; Revalor-IH | Estradiol, Trenbolone Acetate | Intervet, Inc. | Cattle | NADA 140-992 |
| Revalor-XH; Revalor-XS | Estradiol, Trenbolone Acetate | Intervet, Inc. | Cattle | NADA 141-269 |
| Revalor-XR | Estradiol, Trenbolone Acetate | Intervet, Inc. | Cattle | NADA 141-445 |
| Synovex T120; Synovex T40; Synovex T80 | Estradiol, Trenbolone Acetate | Zoetis Inc. | Cattle | ANADA 200-367 |
Species are the major species the Green Book search lists for the application ("—" where it lists another species or none). Approval dates are not part of the Green Book listing files and are not shown. Pioneer applications (NADA) come first, then generics (ANADA).
Questions about estradiol + trenbolone acetate reports
How many adverse event reports has FDA received for the combination estradiol and trenbolone acetate?
267 reports record a drug with the combination estradiol and trenbolone acetate as its active ingredients in the openFDA release of 28 Sep 2026, covering reports received through March 2026. 16 of them arrived in the latest 12 months.
Which brand do these reports concern?
That cannot be known from the public data. openFDA masks brand and manufacturer names in adverse event records, so the reports counted here cannot be attributed to a particular brand. The Green Book lists 5 approved applications with this combination; the reference list on this page names them without any counts.
What signs are reported most often?
death (22.5%), increased sexual interest (14.2%), underfilling, Package (11.2%), implant, Abnormal (10.9%) and color, Abnormal (10.1%). These are the coded terms listed in reports; several can appear in one report, and a term's presence is not a finding that the drug was responsible.
Which species and breeds appear in these reports?
cattle (61%), human exposure (1.5%) and dog (0.4%). Among single-breed animals the most frequent labels are Holstein-Friesian, Aberdeen Angus, Beefmaster and Charolais; popular breeds appear often in any drug's reports because there are more of them.
Are reports rising?
16 reports in the 12 months to March 2026, up 700% from 2 in the 12 months before. FDA posts reports quarterly with a delay of three to six months, so the newest months are incomplete and usually grow in later releases. Counts also move with sales, publicity and time on the market.
Do these reports show that estradiol + trenbolone acetate harms pets?
Report counts cannot show that. FDA states that "there is no certainty that the reported drug or device caused the adverse event" and that the event "may have been related to an underlying disease, other drugs used at the same time or other non-drug related sources." FDA also notes that commonly used products may have more reports simply because more animals receive them.
Are these the side effects of estradiol + trenbolone acetate?
They are signs listed in reports, not an established list of side effects. The adverse reactions observed in studies are printed on each product's FDA-approved label, which a veterinarian can go through with you. This page is a record of what was reported to FDA.
How do I report a problem with an animal drug?
FDA asks owners and veterinarians to call the drug company first (the number is on the label); companies must pass reports to FDA. Reports can also go directly to FDA on Form FDA 1932a. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Animal & Veterinary adverse event bulk files released 28 Sep 2026, which hold reports FDA's Center for Veterinary Medicine received through 31 Mar 2026. openFDA masks brand and manufacturer names in these files, so drugs are counted by the active ingredients each record discloses and no figure is attributed to a brand, application or company. Ingredient names, and the separate reference lists of approved products, follow the FDA Green Book as of 1 Oct 2026. Drug entries are grouped by the active ingredients their unmasked ingredient field discloses; the application number that records also carry is not used. No report text, lot numbers or reporter details are published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.