This is a double blinded, randomised, crossover study with 12 healthy men between 18 and 40 year. The design is based on 6 days:

• day 1: On day time administration of LPS.
• day 2: On night time administration of LPS.
• day 3: On day time administration of LPS + Placebo.
• day 4: On day time administration of LPS + melatonin.
• day 5: On night time administration of LPS + placebo.
• day 6: On night time administration og LPS + melatonin.

Measuring the inflammatoric and oxidative response of LPS and the effect of melatonin compared to placebo on the endotoxaemia.

Inclusion Criteria:

• Men
• Age 18-49 year.
• Healthy
• No sleepiness disorders.
• No medication
• ASA I

Exclusion Criteria:

• Allergia to melatonin
• Women
• Smoking.
• Alcohol abuse.