10 Essential Facts About Melatonin

3. Light Levels Can Affect Melatonin Effectiveness

The effectiveness of melatonin supplements can vary based on the amount and type of light in a person's sleeping or pre-sleep environment -- their bedroom or living room. The brain regulates the release of melatonin based on exposure to different kinds of light. When an environment has more light, the brain assumes it is daytime and produces less melatonin. Darkness encourages production because the brain interprets this as night. This is why some people who use their screen devices late into the night can have difficulty falling asleep -- the body has insufficient melatonin because the brain misinterpreted this light.