For additional improvement in rate of weight gain in steers fed in confinement for slaughter, may be used as part of a re-implant program where an initial Synovex C or S implant is followed at approx 70 days by Synovex S.


Each dose contains 200 mg progesterone and 20 mg estradiol benzoate. 


100 Dose (10 Dose Clips)


Manufacturer: Zoetis US LLC






    Telephone:  269-359-4414
    Customer Service:  888-963-8471
      Every effort has been made to ensure the accuracy of the information published. However, it remains the responsibility of the readers to familiarize themselves with the product information contained on the USA product label or package insert.



    (progesterone and estradiol benzoate implants)

    200 mg progesterone and 20 mg estradiol benzoate per implant


    Increased Rate of Weight Gain and Improved Feed Efficiency

    For additional improvement in rate of weight gain in steers fed in confinement for slaughter, reimplant at approximately 70 days.

    NOTE: Studies have demonstrated that reimplantation of Synovex S can decrease marbling scores when compared to non-implanted controls.

    This product was manufactured by a non-sterilizing process.

    Important: Read ALL sides of carton

    For Steers Only

    Do Not Use In Veal Calves

    Not For Use In Humans

    For Animal Use Only

    For subcutaneous ear implantation only.

    Approved by FDA under NADA # 009-576

    Synovex S Steer Implants contain two pure steroid hormones, progesterone and estradiol benzoate. This formulation provides a complementary amount of each hormone for maximal growth stimulation. Study the enclosed instructions carefully and use this product only as illustrated.


    (progesterone and estradiol benzoate)

    200 mg progesterone and 20 mg estradiol benzoate per implant


    Study the following instructions carefully, then proceed step by step, until the technique becomes routine. Many head can be implanted per hour by an experienced team, one member of which should be assigned to do nothing but the implantation. This person should maintain hand cleanliness and use sanitary instruments only.


    100 Dose

    SYNOVEX® S (progesterone and estradiol benzoate implants)

    200 mg progesterone and 20 mg estradiol benzoate per implant


    Synovex S (progesterone and estradiol benzoate implants) is recommended for use in steers weighing 400 lbs or more.

    When properly administered, Synovex S implants increase rate of weight gain and improve feed efficiency. Do not use in veal calves. Effectiveness and animal safety in veal calves have not been established.

    Store at controlled room temperature 20°-25°C (68°-77°F) with excursions between 15°-30°C (59°-86°F). Avoid excessive heat or humidity.



    Not for use in humans. For animal use only. Implant pellets in the ear only. Any other location is in violation of federal law. Do not attempt salvage of implanted site for human or animal food.

    A withdrawal period has not been established for this product in pre-ruminating calves. Do not use in calves to be processed for veal.



    Bulling, rectal prolapse, ventral edema and elevated tailheads have been occasionally reported in steers administered with Synovex S implants.

    Keep this and all drugs out of the reach of children.

    Restricted Drug (California) - Use Only as Directed.

    DIRECTIONS: Implant complete contents of one cartridge cell per steer. Approved implantation technique is fully described in the package insert.

    NOTE: Never sacrifice careful, clean technique for speed of implantation.

    STEP 1 Loading the Applicator

    Load the applicator following the directions outlined in the instruction manual accompanying each applicator.

    Additional information for the individual applicator user guides can be found at:

    STEP 2 Restraint

    The animal must be confined in a restraint mechanism (squeeze chute or head gate). The implant site on the back of the ear should be prepared by scrubbing with a firm bristled brush that has been soaked in a germicidal solution.

    Note: If implanting horned cattle, greater safety is provided when the head is controlled by the use of a bull lead (nose tongs).

    STEP 3 Implant Site

    Divide the ear into three imaginary sections as illustrated. The implanted pellets should be deposited in the center one-third of the ear as shown. To accomplish this, the applicator needle should be inserted in the outer one-third of the ear as indicated by the “X” in the illustration. Implanting too close to the head may cause abnormal sexual behavior. Care should be taken to avoid severing the major arteries of the ear.

    STEP 4 Insert Needle

    Grasp the ear with one hand. While holding the applicator firmly with the other hand, penetrate the skin at the point shown by the “X”. Thrust the needle under the skin taking care not to penetrate the cartilage. Ease the applicator forward (toward the base of the ear) until the full needle length is beneath the skin.

    STEP 5 Pellet Implantation

    When the needle is completely inserted, activate the instrument by squeezing the trigger completely. Refer to instructions for individual applicator.

    STEP 6 Inspection

    Check the implant site. If properly administered, the implants should lie in a straight line under the skin.

    Re-cock the applicator. Disinfect the applicator needle in a germicidal solution. The applicator is now ready to implant the next animal.

    Distributed by: Zoetis Inc., Kalamazoo, MI 49007



    Each Cartridge Contains 10 Rows of 8 Pellets.


    CPN: 3690414.1