What can contribute to elevated estradiol (E2) in menopausal women who are not on hormone replacement therapy (HRT)?

High estradiol can result from exogenous hormone exposure (accidental exposure), excess aromatase activity, environmental exposures to xenoestrogens, chronic liver disease, hyperthyroidism, dysregulated gut microbiome leading to elevated beta-glucuronidase, ectopic production of estradiol from cancerous tissues and other causes.