Effect of melatonin on jet lag after long haul flights.

OBJECTIVE To determine whether doses of the pineal hormone melatonin alleviate jet lag. DESIGN Double blind, placebo controlled crossover trial. SETTING Long haul return flights from Auckland, New Zealand, to London and back. SUBJECTS Twenty volunteers with experience of transcontinental flights (eight women and 12 men aged 28 to 68). INTERVENTIONS Melatonin (or placebo) 5 mg three days before flight, during flight, and once a day for three days after arrival. END POINT Symptoms of jet lag. MEASUREMENTS AND MAIN RESULTS Visual analogue scale for feelings of jet lag and tiredness; profile of moods states questionnaire for vigour-activity and fatigue-inertia; and retrospective ratings 10 days after arrival of sleep pattern, energy, and daytime tiredness. Feelings of jet lag were less for subjects taking melatonin (mean score 2.15 v 3.4); these subjects took fewer days than the placebo group to establish a normal sleep pattern (2.85 v 4.15), to not feel tired during the day (3.0 v 4.6), and to reach normal energy levels (3.25 v 4.7). Results for fatigue-inertia and vigour-activity were similar. For all subjects jet lag was more severe on the return (westward) than the outward (eastward) journey. CONCLUSIONS Melatonin can alleviate jet lag and tiredness after long haul flights.