This chapter highlights the pharmacokinetics and pharmacodynamics of several recombinant products available for use in controlled ovarian stimulation protocol. It summarizes current research regarding follicle-stimulating hormone (FSH), luteinizing hormone (LH), and chorionic gonadotropin (CG) in animal models as these models have important implications in the study and treatment of human infertility. FSH has its action through binding to the FSH receptor (FSHR), a G-protein-coupled receptor. Recombinant human FSH (rhFSH) has been shown to be effective in follicular recruitment in humans and various species of non-human primates including macaques. LH and CG bind with high affinity to the LH receptor (LHR), a glycoprotein G-protein-coupled receptor with seven transmembrane domains. Animal models have been invaluable for the understanding of the activities/actions of LH, FSH, LHR, and FSHR. Recombinant products are effective in follicular recruitment and oocyte maturation and can simulate an endogenous LH surge to induce ovulation.