Effect of melatonin on jet lag after long haul flights

Objective - Two 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 fatigueinertia 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.