Israeli researchers have developed a new method, called CircaSCOPE, to track the body's internal circadian clocks and discovered that female sex hormones, especially progesterone, have a significant impact on these rhythms. Their findings reveal that not only the central clock in the brain but also clocks in nearly every cell are influenced by hormones and stress signals, with disruptions potentially leading to health issues like sleep disorders and diabetes. The study identified the protein CRY2 as the main receiver of these hormonal signals, challenging previous assumptions about how the body's clocks are regulated. This research could help explain changes in sleep patterns during menstruation, pregnancy, and menopause, and may pave the way for new treatments for circadian-related disorders.