<unk> s, also known as androgen antagonists or testosterone blockers, are a class of drugs that prevent androgens like testosterone and dihydrotestosterone (DHT) from mediating their biological effects in the body. They act by blocking the androgen receptor (AR) and/or inhibiting or suppressing androgen production. They can be thought of as the functional opposites of AR agonists, for instance androgens and anabolic steroids (AAS) like testosterone, DHT, and nandrolone and selective androgen receptor modulators (SARMs) like enobosarm.<unk> s are one of three types of sex hormone antagonists, the others being antiestrogens and antiprogestogens.<unk> s are used to treat an assortment of androgen-dependent conditions. In men,<unk> s are used in the treatment of prostate cancer, enlarged prostate, scalp hair loss, overly high sex drive, unusual and problematic sexual urges, and early puberty. In women,<unk> s are used to treat acne, seborrhea, excessive hair growth, scalp hair loss, and high androgen levels, such as those that occur in polycystic ovary syndrome (PCOS).<unk> s are also used as a component of feminizing hormone therapy for transgender women and as puberty blockers in transgender girls. Side effects of<unk> s depend on the type of<unk>  and the specific<unk>  in question. In any case, common side effects of<unk> s in men include breast tenderness, breast enlargement, feminization, hot flashes, sexual dysfunction, infertility, and osteoporosis. In women,<unk> s are much better tolerated, and<unk> s that work only by directly blocking androgens are associated with minimal side effects. However, because estrogens are made from androgens in the body,<unk> s that suppress androgen production can cause low estrogen levels and associated symptoms like hot flashes, menstrual irregularities, and osteoporosis in premenopausal women. There are a few different major types of<unk> s. These include AR antagonists, androgen synthesis inhibitors, and antigonadotropins. AR antagonists work by directly blocking the effects of androgens, while androgen synthesis inhibitors and antigonadotropins work by lowering androgen levels. AR antagonists can be further divided into steroidal<unk> s and nonsteroidal<unk> s; androgen synthesis inhibitors can be further divided mostly into CYP17A1 inhibitors and 5α-reductase inhibitors; and antigonadotropins can be further divided into gonadotropin-releasing hormone modulators (GnRH modulators), progestogens, and estrogens.
Antiandrogen
Antiestrogen
Antiglucocorticoid
Thyroid blocker
Aromatase inhibitor
Nonsteroidal antiandrogen
Antiprogestogen
Phytoestrogen