Gonadotropin-releasing hormone (GnRH) agonist analogs produce an initial release of FSH and LH followed by a suppression of these same hormones.
They have different uses in ovarian stimulation cycles. The most frequent use is at the end of stimulation for ovulatory discharge, also minimizing the risk of ovarian hyperstimulation. The objective of their use during stimulation would be to avoid LH peaks, allowing a more synchronous growth of the follicles and preventing ovulation. In addition, they can be administered before starting an endometrial preparation to extend the implantation window, and they also have their utility in pathologies such as endometriosis.
There are several types of analogs, which differ by small variations of components of the molecule. These would be leuprorelin acetate, triptorelin, nafarelin, buserelin, and goserelin. There are several presentations (daily, monthly, quarterly ...), indicating at each time the most appropriate for the effect you want to achieve. Each type of analog also has its route of administration, which may be subcutaneous, intramuscular, or intranasal.
It has not been demonstrated that any of the agonists marketed is superior to another, although the subcutaneous route provides constant bioavailability and little variation between patients, while intranasal or inhalation absorption may be more variable.