Circadian Melatonin

The Circadian Melatonin test measures the levels of melatonin over a complete dark-light cycle and is measured two times in a day: noon and middle of the night.


About Melatonin


Melatonin is produced by the pineal gland, a small endocrine gland in the brain that regulates the sleep-wake diurnal cycle. The peak production is at night, with low levels during the day.

Melatonin has physiological importance in the control of sleep time and duration, is central to the modulation of both circadian and annual biorhythms and has a remarkably tight association with thermoregulation. It also acts as an antioxidant and plays a role in the regulation of cardiovascular function and female reproductive hormones.    

The Importance of Balanced Melatonin Levels

If Melatonin imbalances occur there can be far reaching effects, including menstrual difficulties, sleep disorders, depression and Seasonal Affective Disorder (SAD). The synthesis and physiological use of melatonin is strongly affected by the length of day, artificial illumination, seasonal changes and aging. Therefore, accurate measurement of melatonin levels and the circadian rhythm are essential for the development of therapeutic regimes, such as timing of artificial light and melatonin administration.  


Sample Circadian Melatonin test report (optimized for Internet Explorer, Firefox and Safari)


Saliva Sample Collection - Frequently Asked Questions