PHARMACOLOGY
The activity of melatonin, mainly at the MT1, MT2 and MT3 receptors, is believed to contribute to its sleep-promoting properties, as these receptors are involved in the regulation of circadian rhythms and sleep regulation.

CLINICAL STUDIES
The efficacy of Circadin has been assessed in several clinical trials in patients aged over 55, over a treatment period of 3 weeks.

A study¹ conducted in 170 patients showed a clinically significant improvement in both quality of sleep and morning alertness in the Circadin group (47%) compared to placebo (27%).

Another study² conducted in 354 patients showed a clinically significant improvement in both quality of sleep and morning alertness in the Circadin group (26%) compared to placebo (15%). Circadin also reduced patients’ reported sleep latency (time to onset of sleep) by 24.3 minutes compared with placebo, which reduced it by 12.9 minutes.

References
1. Lemoine P, Nir T, Laudon M et al. Prolonged-release melatonin improves sleep quality and morning alertness in insomnia patients aged 55 years and older and has no withdrawal effects. J Sleep Res 2007: 16; 372–80.
2. Wade A, Ford I, Crawford G et al. Efficacy of prolonged release melatonin in insomnia patients aged 55–80 years: quality of sleep and next-day alertness outcomes. Curr Med Res Opin 2007: 23 (10); 2597–605.