Sleep is one of the most common and important things that hormonal changes can affect. Without good quality sleep, it becomes difficult for our bodies to regulate appetite, burn fat, and to feel good especially happy and calm. Poor sleep leads to inflammation in the body, poor blood sugar control, depression, and anxiety. Due to the physiology female hormones play, women suffer from insomnia at nearly twice the rate of men. Low estrogen levels typically cause insomnia, because estrogen helps move magnesium into tissues, which is crucial for catalyzing the synthesis of important sleep neurotransmitters, including melatonin. Therefore, when estrogen levels decline such as in perimenopause (the years preceding menopause, when hormone levels are declining) and menopause, it is both harder to fall asleep and stay asleep throughout the night. Menopause is notorious for causing insomnia, and hot flashes often play a minor role, but insomnia may still plague women for many years even without hot flashes. Researchers have found that women who have hot flashes during perimenopause are also more likely to have sleep disturbances. Since the ovaries stop producing the hormones estrogen and progesterone at this time, menopause can be a direct cause of insomnia. A lack of testosterone can also be an issue for women since diminished testosterone is linked with snoring and sleep apnea. Over the course of many years after menopause, women’s bodies can adjust and respond to a low estrogen signal, but this can take a significant amount of time and is problematic. Balancing hormones through bio-identical hormone replacement therapy and developing healthy sleep habits provides relief from sleeplessness and insomnia.