What role does Östradiol play in Müdigkeit?

Estradiol, the primary estrogen, modulates energy metabolism via receptors in the brain and mitochondria. A drop in estradiol levels – e.g., during the late luteal phase, postpartum, or menopause – is commonly linked to fatigue, low energy, and sleep disruption. Proposed mechanisms include reduced mitochondrial biogenesis, lower serotonin synthesis, and altered circadian rhythms. However, the evidence is largely observational; no robust RCTs directly prove a causal role of estradiol in fatigue among healthy individuals. Individual responses vary widely. For persistent or severe fatigue, other causes (thyroid, iron deficiency, sleep apnea) should be medically evaluated. Evidence grade: mechanistic/observational.