Pharmacodynamics The mechanism of action of<unk>  is complex and multifaceted. It shows high affinity for the progesterone receptor (PR), as well as lower affinity for the androgen receptor (AR). The medication has mixed progestogenic and antiprogestogenic activity – that is, it is a partial agonist of the PR or a selective progesterone receptor modulator (SPRM) – and is a weak agonist of the AR, or an anabolic–androgenic steroid (AAS). Similarly to danazol,<unk>  acts as a weak antigonadotropin via activation of the PR and AR in the pituitary gland and suppresses the mid-cycle surge of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) during the menstrual cycle without affecting basal levels of these hormones. It also inhibits ovarian steroidogenesis and, via activation of the AR in the liver, decreases circulating levels of sex hormone-binding globulin (SHBG), thereby resulting in increased levels of free testosterone. In addition to the PR and AR,<unk>  has been found to bind to the estrogen receptor (ER) with relatively "avid" affinity. The medication has functional antiestrogenic activity in the endometrium. Unlike danazol,<unk>  does not appear to bind to SHBG or corticosteroid-binding globulin (CBG). Relative affinities (%) of<unk>  and related steroids Compound Norethisterone 155–156 43–45 <0.1 2.7–2.8 0.2 ? ? Norgestrienone 63–65 70 <0.1 11 1.8 ? ? Levonorgestrel 170 84–87 <0.1 14 0.6–0.9 ? ?<unk>  75–76 83–85 <0.1, 3–10 77 3.2 ? ? Notes: Values are percentages (%). Reference ligands (100%) were progesterone for the , testosterone for the , for the , for the , aldosterone for the , for , and cortisol for . Sources: Pharmacokinetics<unk>  is bound to albumin in the circulation. It is metabolized in the liver mainly by hydroxylation. Four hydroxylated active metabolites with reduced activity relative to<unk>  have been found to be formed. The elimination half-life of<unk>  is 27.3 hours. The medication is excreted in urine and bile.
Gestrinone
Gestodene
Mestanolone
Goserelin
Anastrozole
Oxandrolone
Allenestrol
Hexestrol