Most people identify melatonin as the "vampire hormone" that emerges at night to help us fall asleep. It is better described as a darkness signal: it tells every tissue in your body that night has arrived. Researchers are also studying roles well beyond sleep.
Mitochondrial Protection#
In lab and animal studies, melatonin acts as an antioxidant inside mitochondria, the power plants of your cells. Whether that translates to energy or longevity benefits in people isn't established.
Brain Health and Detoxification#
Deep sleep is when the brain's glymphatic system clears waste such as amyloid-beta, a protein linked with cognitive decline. Melatonin's direct role in that is still being studied. More on the glymphatic system.
Natural Optimization Methods#
Before reaching for supplements, focus on natural triggers. Darkness is the primary signal for melatonin release, and dim, warm light in the evening keeps it from being suppressed (our evening light guide covers the details). A cool room helps the drop in body temperature that goes with sleep.
If you're considering a melatonin supplement, talk to your doctor or pharmacist first. Low doses (0.5–1 mg) are commonly used for shifting sleep timing, and it isn't for children without medical advice.
Your morning light sets when tonight's melatonin rise happens (see the science of morning sunlight). ARC's 20-minute light timer and its wind-down notification bracket the two ends of that.