Hormones and Sleep: How Testosterone & Estrogen Affect Circadian Rhythms — And Why That Matters for Sleep
Most discussions of circadian rhythm begin and end with melatonin—the molecule that signals darkness and helps us drift off at night. Yet melatonin is only one part of a much broader timing network.
Inside that same network, testosterone, estrogen, and progesterone communicate directly with the brain’s master clock—the suprachiasmatic nucleus (SCN)—shaping how the body aligns its daily cycles of temperature, metabolism, and recovery.
Understanding how these sex hormones interact with circadian biology offers a more complete picture of why sleep becomes lighter, shorter, or less restorative with stress and age—and how to rebuild stability from within.
