ATC G03 — Sex hormones and modulators of the genital system

Drospirenone is a fourth-generation progestogen with anti-mineralocorticoid and anti-androgen activity. It is widely used in combined oral contraceptives (Yaz, Yasmin) and in a progestogen-only pill (Slynd), often preferred for premenstrual symptoms and acne.

Levonorgestrel is a synthetic progestin used as emergency contraception (single 1.5mg dose), in combined oral contraceptives, hormonal IUDs and progestin-only pills. Most effective for emergency use within 72 hours of unprotected intercourse.

Testosterone is the principal androgen in men, used clinically as replacement therapy for confirmed hypogonadism. It is available as topical gels, injectable esters, transdermal patches and subcutaneous pellets, with selection driven by patient preference and monitoring needs.

Ethinyl estradiol is the synthetic estrogen used in nearly all combined hormonal contraceptives — pills, patches and vaginal rings. Its high oral potency and long duration make it suitable for once-daily contraceptive dosing combined with a progestin. It is on the WHO Essential Medicines List.

Estradiol is the principal natural estrogen in women, used as bioidentical hormone replacement therapy for menopausal symptoms and prevention of osteoporosis. It is available as oral tablets, transdermal patches and gels, vaginal creams, rings and tablets, allowing dose and route to be tailored.

Estriol is the weakest of the three natural estrogens, used primarily as topical vaginal therapy (Ovestin cream, pessaries) for postmenopausal urogenital atrophy. Its weak systemic effect and short half-life make it suited for local relief with minimal systemic exposure.

Conjugated estrogens are a mixture of estrogen sulfates derived from pregnant mare urine, used in postmenopausal hormone replacement therapy. Available as oral tablets and topical formulations, marketed primarily as Premarin.

Tibolone is a synthetic steroid for postmenopausal HRT with tissue-selective estrogenic, progestogenic and weak androgenic activity. It is widely available in Europe (Livial) but not approved in the United States; one tablet daily covers combined HRT in a single molecule.

Medroxyprogesterone acetate (MPA) is a synthetic progestin used as oral therapy (Provera) for menstrual cycle disorders and as part of menopausal HRT, and as a long-acting injectable contraceptive (Depo-Provera) given every 12 weeks. It has anti-estrogenic and anti-gonadotrophic effects.

Progesterone is a natural female sex hormone used as bioidentical replacement in menopausal hormone therapy (in combination with estradiol), in luteal-phase support during IVF, and in selected gynaecological indications. Available as oral micronised capsules and vaginal gels, capsules or inserts.

Norethindrone is a first-generation oral progestin in clinical use since 1957. It is used in progestin-only contraceptive 'mini-pills', combined with ethinyl estradiol in many combined oral contraceptives, and as monotherapy at higher dose for abnormal uterine bleeding and endometriosis.

Clomiphene is a selective estrogen receptor modulator used to induce ovulation in selected women with anovulatory infertility. Taken as a 5-day course early in the menstrual cycle, typically under fertility specialist supervision.

Raloxifene is a selective estrogen receptor modulator (SERM) used for prevention of postmenopausal osteoporosis and reduction of invasive breast cancer risk. It activates estrogen receptors in bone while blocking them in breast and uterus, offering targeted benefit without HRT estrogenic effects.