Melatonin has sedative, hypnotic and analgesic properties that make it a good premedication agent before anesthesia and surgery.

In this study the investigators intend to randomise 60 patients undergoing bariatric surgery into two groups. The participants will receive either melatonin or placebo on the evening prior to the surgery, and the same agent two hours before the surgery.

The patients recovery from the surgery and anesthesia will be assessed using the Q0R15 questionnaire. The patients will be asked to take the questionnaire once in the pre-operative clinic, again after the second melatonin or placebo pill before entering the operating room, and once more on the first post-operative day.

Melatonin has sedative, hypnotic, analgesic, antiinflammatory, and chronobiologic properties that make it a good premedication agent before anesthesia and surgery. Patients undergoing surgery in our establishment usually receive benzodiazepines as premedicants to reduce anxiety before the surgery. For bariatric patients benzodiazepines are usually avoided due to side effects which could be deleterious in obese patients.

In this study the investigators intend to randomise 60 patients undergoing bariatric surgery into two groups. The participants will receive either melatonin or placebo on the evening prior to the surgery, and the same agent two hours before the surgery.

The patients recovery from the surgery and anesthesia will be assessed using the Q0R15 questionnaire. The patients will be asked to take the questionnaire once in the pre-operative clinic, again after the second melatonin or placebo pill before entering the operating room, and once more on the first post-operative day.

Inclusion Criteria:

• Patients undergoing bariatric surgery

Exclusion Criteria:

• Known allergy to melatonin