PLOD1 and central precocious puberty: Monthly and 3-monthly depot leuprolide [2-5] and the annual histrelin implant [6,7] are the most commonly used therapies in the U.S. Serum LH response to GnRH or GnRHa stimulation, typically using aqueous leuprolide acetate as the stimulating agent, is the conventional test used to diagnose CPP [8-15] in conjunction with sex steroid levels and characteristic clinical features.