Estradiol
Status
FDA-approved. FDA-approved labeling exists for treatment of moderate to severe vasomotor symptoms and vulvovaginal atrophy due to menopause, hypoestrogenism and prevention of postmenopausal osteoporosis. It carries a boxed warning covering endometrial cancer, cardiovascular disorders, breast cancer and probable dementia.
What it is
The main estrogen used in prescribed hormone therapy, in several forms.
What published research measured
The principal endogenous oestrogen, given for menopausal symptoms with one of the largest and most argued-over evidence bases in medicine. The Women's Health Initiative dominates it, and its findings are frequently reported without the qualifications that matter: the increased breast cancer signal was in the combined oestrogen-plus-progestin arm, while the oestrogen-alone arm in women with hysterectomy showed no increase and in longer follow-up a reduction; and the average participant was well past menopause at enrolment. Subsequent analysis supports a timing hypothesis, with a more favourable cardiovascular balance when started near menopause onset. Route matters: transdermal delivery avoids hepatic first pass and observational evidence associates it with lower venous thromboembolism risk than oral. Unopposed oestrogen in a woman with a uterus causes endometrial hyperplasia and carcinoma, which is why progestogen is co-prescribed.
Source
Women's Health Initiative (WHI), oestrogen-alone and oestrogen-plus-progestin arms · FDA class labeling for oestrogen therapy, including the boxed warning
Sources
No linked primary source is on file for this entry yet.
Educational use only, never medical advice. No doses.