Salivary Melatonin

Salivary melatonin concentrations represent about one quarter to one third of concurrent plasma concentrations. The salivary-to-plasma melatonin relationship has not been established in surgical patients. Prior non-surgical studies showed strong correlations between salivary and blood melatonin measures. Adequate saliva collection may be difficult during the perioperative period. Salivary melatonin is being evaluated as a non-invasive alternative or complement to blood-based circadian monitoring.