(Pfizer Animal Health) Factrel is indicated for the treatment of ovarian follicular cysts in cattle. Factrel may be used with Lutalyse to synchronize estrus cycles to allow fixed-time artificial insemination in lactating dairy cows. Each ml of Factrel solution contains 50 micrograms of synthetic gonadorelin hydrochloride. Gonadorelin is the gonadotropin releasing hormone (GnRH). Factrel has the identical amino acid sequence as endogenous gonadorelin. For treatment of ovarian follicular cysts, the recommended dosage of Factrel is 2 ml per cow, given IM. For use with Lutalyse to allow fixed-time artificial insemination, administer 2-4 ml Factrel per cow, given IM; administer 5 ml of Lutalyse on day 7; repeat Factrel on day 9, inseminate 24 hours later. Gonadorelin (GnRH) hydrochloride.