Relugolix-d6 is a deuterated compound of Relugolix. Relugolix has a CAS number of 737789-87-6. Relugolix is an orally available, non-peptide gonadotropin-releasing hormone (GnRH or luteinizing hormone-releasing hormone (LHRH)) antagonist, with potential antineoplastic activity. Relugolix competitively binds to and blocks the GnRH receptor in the anterior pituitary gland, which both prevents GnRH binding to the GnRH receptor and inhibits the secretion and release of both luteinizing hormone (LH) and follicle stimulating hormone (FSH). In males, the inhibition of LH secretion prevents the release of testosterone from Leydig cells in the testes. Since testosterone is required to sustain prostate growth, reducing testosterone levels may inhibit hormone-dependent prostate cancer cell proliferation.