Съобщеното от пациентите качество на съня, брой на събуждания и сутрешна бодрост са значимо подобрени с Circadin в сравнение с плацебо.
In a second outpatient study with two week run in baseline period with placebo and a randomised, double blind, placebo controlled, parallel group treatment period of 3 weeks, the rate of patients who showed a clinically significant improvement in both quality of sleep and morning alertness was 26% in the Circadin group as compared to 15% in the placebo group.