Synovex

**Synovex** is a brand of growth-promoting subcutaneous ear implants for beef cattle, developed by Zoetis, primarily used to increase rate of weight gain and improve feed efficiency in growing steers and heifers fed in confinement or dry lot for slaughter. Different formulations contain combinations of **trenbolone acetate** (an anabolic steroid acting as an androgen receptor agonist), **estradiol benzoate** (an estrogen mimicking hormone), or **progesterone** (a progestin), with dosages varying by product (e.g., Synovex S: 200 mg progesterone + 20 mg estradiol benzoate; Synovex Plus: 200 mg trenbolone acetate + 28 mg estradiol benzoate; Synovex Primer: 50 mg trenbolone acetate + 7 mg estradiol benzoate). Administered via specialized applicators, these implants provide effects for 70-200 days depending on the variant, but may reduce marbling scores upon reimplantation and are not approved for veal calves, dairy cows, or breeding animals.[1][2][3][4][7]

Brand names

Synovex

Other names

Synovex SSynovex PlusSynovex ChoiceSynovex PrimerSynovex ONE Grower