Circadian disturbances occur after surgery. A double blinded, placebo controlled randomized clinical trial was made to investigate effects of melatonin on postoperative fatigue, sleep disturbances and general wellbeing.

Postoperative fatigue and sleep disturbances occur after minimally invasive surgery. The pathophysiological background is unknown, but several studies have shown disturbed melatonin secretion after surgery. It is unknown whether melatonin substitution will improve general wellbeing, fatigue or sleep disturbances after laparoscopic cholecystectomy. We set out to study in a randomized clinical trial to investigate the effect of 5 mg melatonin versus placebo, on postoperative sleep disturbances, fatigue and general wellbeing.

Inclusion Criteria:

• Operation for gall bladder disease
• Age over 18 years

Exclusion Criteria:

• Known preoperative sleep disturbance
• Anticoagulant therapy
• Psychiatric disease
• Lack of written informed consent
• Treatment with hypnotics within one week prior to surgery