Serum Melatonin Concentration (pg/mL)

Melatonin is one of the three standard bio-markers for mammalian circadian rhythms (along with Cortisol and Body Temperature). Essentially, you ought to feel sleepier the higher your Serum Melatonin Concentration is. Measured in picograms per milliliter, Serum Melatonin Concentrations provide helpful insight into the nature of sleep. Analyze your circadian rhythm by looking at the graph below. This graph represents the average human Serum Melatonin Concentrations over a 24 hour period of time.

This document requires an HTML5-compliant browser.
Total Daily Concentration of Serum Melatonin (pg/mL)
Time (hours) and Current Serum Melatonin Concentration (pg/mL)

Source: National Institutes of Health:, Journal of Biological Rhythms:

App generated by Geometry Expressions