Estradioli

Estradioli is the plural form used in some languages to refer to estradiol, the primary endogenous estrogen in humans. The principal natural form is estradiol-17β, a steroid hormone produced mainly by ovarian granulosa cells in the follicles, with smaller amounts synthesized by theadrenal glands and adipose tissue. In premenopausal people, estrogen levels rise and fall with the menstrual cycle, peaking before ovulation; after menopause, production declines markedly. In males, small amounts are produced by the testes and other tissues, contributing to normal reproductive and metabolic functions.

Estradiol acts by binding estrogen receptors, primarily ERα and ERβ, to regulate gene expression and activate non-genomic signaling pathways. It influences a wide range of tissues, including the reproductive tract, bones, cardiovascular system, skin, and brain. Physiological roles include development of female secondary sexual characteristics, regulation of the menstrual cycle and endometrial preparation for pregnancy, maintenance of bone density, and modulation of mood and cognition.

Clinically, estradiol is used in hormone replacement therapy to treat menopausal symptoms and prevent bone loss, in combined hormonal contraceptives, for hypogonadism, and as part of gender-affirming hormone therapy. It can be administered orally, transdermally, vaginally, intramuscularly, or via implants. Oral forms undergo first-pass metabolism, while non-oral routes can have different pharmacokinetic and hepatic effects.

Safety and monitoring considerations include the risk of thromboembolism, hypertension, breast tenderness, and nausea. Contraindications include pregnancy, active liver disease, and estrogen-sensitive cancers. Long-term therapy requires regular monitoring of blood pressure, lipid profile, liver function, and, when appropriate, bone density and cancer screening.