Days 11 through 13 marked the treatment period of the study, during which the participants slept in the lab in individual, dark, temperature-controlled bedrooms. Each afternoon, each person received either 0.5 or 3.0 mg of melatonin or matching placebo. The study ended with a final phase assessment on day 14.
The researchers found that those given melatonin experienced significantly larger phase advances -- the 0.5 mg group at 2.5 hours and the 3.0 mg group at 2.6 hours versus the placebo group at 1.7 hours. Moreover, the participants did not experience jet lag�type symptoms. There was a slightly larger phase shift with the 3.0 mg dose compared to the 0.5 dose; however, the difference was not statistically significant. In addition, the higher melatonin dose made the participants slightly more sleepy in the evenings after taking the pill. Therefore, the researchers recommend using the 0.5 dose in combination with morning intermittent bright light to advance their sleep schedule.
"The findings are very practical," said Dr. Eastman. "A business person could go to a pharmacy and buy 0.5 mg of melatonin over the counter. He or she would also have to buy or rent a light box. Then before flying east, he or she could go to bed and wake up earlier each day while using the light box in the morning and taking melatonin in the evening. If they did this for the number of days equivalent to the number of time zones crossed, then they should be completely adjusted to the new time zone before they fly," she added. "However, even following th
Source:The Endocrine Society & The Hormone Foundation