SYNOVEX

Manufacturer
Zoetis Inc.
Effective date
2026-04-06
Label type
OTC ANIMAL DRUG LABEL
Version
5
Source
full-release
Hydrated at
2026-06-01 02:46:47

Label at a glance#

ProductSynovex One
Active ingredienttrenbolone acetate, estradiol benzoate
Label structure15 sections

Dosage and administration

Administer one SYNOVEX® ONE Feedlot implant (eight pellets), containing 200 mg trenbolone acetate and 28 mg estradiol benzoate, to each steer or heifer by subcutaneous implantation in the middle-third of the ear. If using in a reimplantation program, reimplant steers or heifers with a SYNOVEX® ONE Feedlot implant 60 to 120 days after administering a SYNOVEX Choice® implant. Use only a SYNOVEX applicator. Approved ...

Storage and handling

Store unopened product at controlled room temperature 20°-25°C (68°-77°F) with excursions between 15°-30°C (59°-86°F). Avoid excessive heat and humidity. Use product before the expiration date on the label. Once the pouch is opened, unused product may be stored in the end-folded pouch (away from light) for up to six months under refrigerated conditions 2°-8°C (36°-47°F) or at room temperature 20°-25°C (68°-77°F) w...

Label contents#

Full prescribing information#

SPL UNCLASSIFIED SECTION

SYNOVEX® ONE FEEDLOT
(trenbolone acetate and estradiol benzoate extended-release implants)
200 mg trenbolone acetate and 28 mg estradiol benzoate per implant

SUBCUTANEOUS IMPLANTS FOR STEERS AND HEIFERS FED IN CONFINEMENT FOR SLAUGHTER

DESCRIPTION SECTION

SYNOVEX® ONE Feedlot (trenbolone acetate and estradiol benzoate extended-release implants) is a growth promoting implant containing 200 mg of trenbolone acetate and 28 mg of estradiol benzoate per implant with a porous polymer film coating that extends the pay-out period of the final formulation up to 200 days. Each implant consists of 8 pellets. Ten implants are provided in each cartridge.

NOTE: Administration of a single SYNOVEX® ONE Feedlot implant or its use in a reimplantation program with a SYNOVEX Choice® implant may result in decreased marbling scores when compared to non-implanted steers and heifers.

WITHDRAWAL PERIODS AND RESIDUE WARNINGS

SPL UNCLASSIFIED SECTION

No withdrawal period is required when used according to labeling.
Do not use in beef calves less than 2 months of age, dairy calves, and veal calves. A withdrawal period has not been established for this product in pre-ruminating calves.
Do not use in dairy cows or in animals intended for subsequent breeding. Use in these cattle may cause drug residues in milk and/or in calves born to these cows.
Implant pellets subcutaneously in ear only. Any other location is a violation of Federal law. Do not attempt salvage of implanted site for human or animal food.

USER SAFETY WARNINGS

USER SAFETY WARNINGS SECTION

Not for use in humans. Keep out of reach of children.

ANIMAL SAFETY WARNING

SPL UNCLASSIFIED SECTION

Bulling has occasionally been reported in implanted steers and heifers. Vaginal and rectal prolapse, udder development, ventral edema and elevated tailheads have occasionally been reported in heifers administered SYNOVEX® ONE Feedlot implants.

DIRECTIONS

SPL UNCLASSIFIED SECTION

Administer one SYNOVEX® ONE Feedlot implant (eight pellets), containing 200 mg trenbolone acetate and 28 mg estradiol benzoate, to each steer or heifer by subcutaneous implantation in the middle-third of the ear. If using in a reimplantation program, reimplant steers or heifers with a SYNOVEX® ONE Feedlot implant 60 to 120 days after administering a SYNOVEX Choice® implant.

Use only a SYNOVEX applicator. Approved implantation technique is fully described in the fold-out carton section. Never sacrifice careful, clean technique for speed of implantation.

STORAGE

STORAGE AND HANDLING SECTION

Store unopened product at controlled room temperature 20°-25°C (68°-77°F) with excursions between 15°-30°C (59°-86°F). Avoid excessive heat and humidity. Use product before the expiration date on the label.

Once the pouch is opened, unused product may be stored in the end-folded pouch (away from light) for up to six months under refrigerated conditions 2°-8°C (36°-47°F) or at room temperature 20°-25°C (68°-77°F) with excursions between 15°-30°C (59°-86°F) for up to one month.

DISPOSAL

ENVIRONMENTAL WARNING SECTION

SYNOVEX® ONE Feedlot waste materials should be disposed of according to prescribed Federal, State, and Local guidelines.

INDICATIONS FOR USE

SPL UNCLASSIFIED SECTION

•For increased rate of weight gain and improved feed efficiency for up to200 days in growing beef steers and heifers fed in confinement for slaughter.
•For increased rate of weight gain for up to 200 days in growing beef steersand heifers fed in confinement for slaughter in a reimplantation programwhere SYNOVEX Choice® is the first implant and a SYNOVEX® ONEFeedlot implant is administered 60 to 120 days later.
•Other than as described on the labeling, this implant is not approved forrepeated implantation (reimplantation) with any other cattle ear implant ingrowing beef steers and heifers fed in confinement for slaughter as safetyand effectiveness have not been evaluated.

Do not use in beef calves less than 2 months of age, dairy calves, and veal calves because effectiveness and safety have not been established.
Do not use in animals intended for subsequent breeding, or in dairy cows.

QUESTIONS/COMMENTS?

SPL UNCLASSIFIED SECTION

For a copy of the Safety Data Sheet or to report side effects, contact Zoetis Inc. at 1-888-963-8471. For additional informationabout reporting side effects for animaldrugs, contact FDA at 1-888-FDA-VETS orhttp://www.fda.gov/reportanimalae.

SPL UNCLASSIFIED SECTION

SYNOVEX Choice® (trenbolone acetate and estradiol benzoate implants) is owned by Zoetis.

Manufactured By A Non-Sterilizing Process

Restricted Drug (California)—Use Only As Directed.

IMPORTANT

SPL UNCLASSIFIED SECTION

Read ALL sides of carton

SPL UNCLASSIFIED SECTION

Approved by FDA under NADA # 141-348

zoetis

Distributed by:
Zoetis Inc.
Kalamazoo, MI 49007

Revision Date: December 2025

40055853

HOW TO IMPLANT

SPL UNCLASSIFIED SECTION

40055853

How to graphic
How to graphic
steps graphic
steps graphic

PRINCIPAL DISPLAY PANEL - 10 Cartridge Implant Carton

PACKAGE LABEL.PRINCIPAL DISPLAY PANEL

40055853

carton header
carton header

DailyMed RxNorm Mappings#

RxCUI, RxNorm string, TTY table
RxCUIRxNorm stringTTYSPL version
1649908SYNOVEX PLUS 200 MG / 28 MG Drug ImplantPSN5
1549470trenbolone acetate 200 MG / estradiol benzoate 28 MG Drug ImplantPSN5
1649908estradiol 3-benzoate 28 MG / trenbolone acetate 200 MG Drug Implant [Synovex]SBD5
1549470estradiol 3-benzoate 28 MG / trenbolone acetate 200 MG Drug ImplantSCD5
1549470estradiol benzoate 28 MG / trenbolone acetate 200 MG Drug ImplantSY5
1649908SYNOVEX PLUS 200 MG / 28 MG Drug ImplantSY5

Product Linked Resources#

Resource, Code type, Value table
ResourceCode typeValueEquivalent identifiersSource image
Data codeQR Codewww.synovex.comsynovex-one-feedlot-1.jpg

DailyMed Product Concepts#

Product concept, Relation, Version table
Product conceptRelationVersionEffective
5bec24fd-caeb-8b32-1ff0-ca0dd1751379Product name220250618
3fcaf367-cbc2-4d1e-845e-e1ce4b0d86a6Product name220250616
4ca088c7-0c0e-114d-ffaa-d1b94f9eadc1Product name620250311
99d68ea7-fba4-0d7b-b5fa-468e21dd1cbfProduct name220250204
a1c50ef5-9c2c-d846-1ca1-70fabf2428e1Product name320240507
66263a7f-f64d-41c4-90f1-2cee106617ccProduct name120240501
76820076-f087-4073-b1d1-aa04b361335eProduct name220220921
132e7bcf-ca42-94e4-3c78-c44ae7819a94Product name320220126
0a040ba8-1f34-4328-bb07-4f64503daaabProduct name220210513
833edb59-a012-45c2-aff5-2ed74b66fa59Product name120201207
f4d31098-441e-52d3-27f1-49c829f8a3a1Product name520190703
001f367b-fa14-49a0-865b-b395f2553601Product name220190611
3f090665-4687-4bb4-8790-8efb1930ee74Product name120180801
7a549f52-8b99-472c-8b1d-3a70c53c9bf4Product name120160623
3ca8d96e-517a-05ea-5690-f8e1d3726540Product name120140508
5f44c957-835a-ada0-662f-5b1071b7a68bProduct name120140508
7d6c8f26-fe65-2465-c993-66dd6e1c1183Product name120140508
83cac4be-cfee-33c1-5b8e-bb83ae18bce4Product name120140508
c3f7be78-e6d7-47c9-c840-70c566e8d5c4Product name120140508
d6b36b6b-65d6-a810-0fa7-61ddf1a96352Product name120140508

DailyMed Package Descriptions#

Package NDC, Product, Description table
Package NDCProductDescriptionFormQuantityStrengthSPL version
54771-2010-1Synovex One10 in 1 CARTRIDGEIMPLANT105
54771-2010-1Synovex One10 in 1 CARTONIMPLANT105

DailyMed Socrata Ingredients#

Ingredient, Type, UNII table
IngredientTypeUNIISPL versionUploaded
estradiol benzoateACTIVE INGREDIENT1S4CJB5ZGN1
trenbolone acetateACTIVE INGREDIENTRUD5Y4SV0S1
estradiolACTIVE MOIETY4TI98Z838E1
trenboloneACTIVE MOIETYP53R4420TR1

Products#

Every source-derived product name is available through these pages.

DailyMed product names page 1 of 1 · 6 matching rows.

NDC Codes#

Product NDC, Package NDC table
Product NDCPackage NDC
54771-201054771-2010-1

Ingredients#

Every source-derived ingredient row is available through these pages.

DailyMed ingredient rows page 1 of 1 · 2 matching rows.

Name, UNII, Kind table
NameUNIIKind
trenbolone acetateRUD5Y4SV0SACTIB
estradiol benzoate1S4CJB5ZGNACTIB

Source Document#

Source XML · Source PDF

Reported adverse events (FAERS/openFDA)#

Adverse event summaries are temporarily unavailable. Other product information remains available.