Six individual melatonin profiles determined from half hourly saliva samples collected in dim light.

<p>Shown are two melatonin profiles with the lowest AUC (A, B), two melatonin profiles with low AUC but normally shaped melatonin profiles (C, D), and two melatonin profiles with the highest AUC (E, F). The profiles are plotted with reference to assigned bedtime. The peak value of each profile is shown above the corresponding point on the profile. The threshold used to determine the DLMO and DLMOff is represented by the horizontal line. The DLMO and DLMOff are indicated by arrows.