Pregnyl is an injectable, highly purified preparation of human chorionic gonadotropin. It mimics the normal surge of luteinizing hormone (LH) that occurs mid-way through a normal menstrual cycle, and causes ovulation to begin.
It is the next step after follicle stimulation with Follistim AQ Cartridge (follitropin beta injection). Although follitropin beta in the Follistim AQ Cartridge causes the follicles to mature, it does not induce ovulation. Pregnyl helps to induce ovulation and release the mature egg from the follicle.