Evidence check: Östradiol in the context of Schlaf

Estradiol (E2) influences sleep through thermoregulation, circadian rhythm modulation, and neurotransmitter activity (serotonin, GABA). During the luteal phase of the menstrual cycle (high E2), many women report poorer sleep quality, more awakenings, and REM sleep disturbances. In menopause, declining E2 contributes to hot flashes and insomnia, which can be partially alleviated by hormone replacement therapy (HRT). Evidence comes from observational and small interventional studies; large RCTs are limited. Caveat: a single estradiol measurement (e.g., saliva or blood spot) is insufficient to diagnose sleep issues or guide HRT. Sleep hygiene, stress reduction, and medical evaluation (e.g., for sleep apnea or thyroid disorders) are more actionable. The effect of estradiol on sleep is moderate and highly individual.