How Does Melatonin Work for Sleep?
Melatonin levels are dependent on the timing of when you go to bed rather than on keeping us asleep for the whole night. In other words, melatonin may signal your body that it’s time to fall asleep, hence its role in the circadian rhythm.
Although melatonin can be secreted in lymphocytes, platelets, gastrointestinal tract, skin, eyes, and bone marrow, it’s primarily regulated by the pineal gland. When your brain function is optimized, melatonin levels should significantly increase right before you go to sleep.
However, a few common obstacles may disrupt melatonin production in the body. The major problem is exposure to artificial light. We evolved to live according to the natural daily rhythm, with the big burst of melatonin occurring shortly after sunset, making you feel sleepy.
For instance, when the sun sets at 8:00 PM, your body will want you to shut your eyes by 11:00 PM.
It’s difficult to maintain healthy sleep cycles in winter since the early sunset (7 or 8 PM). Most people don’t go to bed that early, and since melatonin effects diminish after 2-3 hours, it’s easy to disrupt your natural sleep-wake cycle.
Artificial light further deteriorates your melatonin balance. Even a brief exposure to blue wavelengths at around 9 or 10 PM may disrupt the time of natural melatonin release by a few hours.