What role does Progesteron play in fatigue?

Progesterone is often discussed in the context of pregnancy and menstrual cycles, but it may also influence fatigue. During the luteal phase, progesterone rises and has mild sedative effects, which could contribute to feelings of tiredness. However, the evidence for a direct causal role of progesterone in chronic fatigue—outside of clear hormonal disorders—is weak. Most studies show small effects that are confounded by lifestyle factors, stress, sleep, and other hormones like cortisol and estrogen. Isolated progesterone deficiency as a cause of fatigue is rare. Blood tests for progesterone are only meaningful at specific cycle phases and should not be interpreted alone. The provided context does not contain specific data on progesterone and fatigue, so the evidence level is assessed as 'unclear'. A thorough medical workup is recommended before attributing fatigue to progesterone imbalance.