Seratonin is a hormone produced naturally in the body. Serotonin (5HT) is another hormone that plays a role in regulating mood and behavior. Both serotonin and melatonin are involved with sleep. Melatonin is synthesized from tryptophan, while serotonin comes from other amino acids such as tyrosine or phenylalanine. Serotonin and melatonin have similar effects on the brain, but they act differently. For example, serotonin affects memory and learning whereas melatonin affects alertness.
Melatonin is best known for its ability to promote sleep; however, it may also play a role in promoting fat burning during sleep. There are several studies which show that taking 5 mg of melatonin before bedtime can increase your metabolic rate during sleep by up to 20%. Melatonin’s effect on metabolism is due to its ability to suppress the release of growth hormones, thereby decreasing insulin levels. This reduces glucose uptake into muscle cells, thus increasing protein synthesis.
This results in increased energy expenditure during sleep.
The mechanism by which melatonin increases metabolism is not completely understood, but there are several theories. One theory suggests that melatonin inhibits the activity of enzymes that convert carbohydrates into sugar and fats into heat (gluconeogenesis). Gluconeogenesis is a process that occurs during sleep and increases the amount of calories burned while sleeping. By decreasing gluconeogenesis, melatonin increases the amount of energy your body burns at night.
Melatonin also affects the amount of insulin, leptin, and reproductive hormones in your body. Leptin is a hormone that regulates hunger. It also plays a role in the regulation of metabolism. Melatonin may increase leptin levels; this may be why melatonin can suppress the appetite.
By increasing leptin, melatonin can decrease hunger and increase the amount of calories you burn at night.
There is evidence that melatonin can improve sleep in blind people who have no perception of light, which is known as free-running disorder (FRD). Melatonin is a treatment for this condition, along with other therapies such as keeping regular sleep and wake schedules.
Melatonin also shows promise as a treatment for insomnia in the elderly. Several studies have demonstrated that melatonin improves sleep efficiency, increases total sleep time, and decreases the amount of time it takes to fall asleep. It is most effective in people whose bodies do not produce melatonin and in people with low levels of melatonin.
Melatonin is a popular dietary supplement that can be used to promote normal sleep patterns, improve sleep quality, and shorten the time it takes to fall asleep. This may be especially beneficial for athletes who need to limit their exposure to sunlight, such as swimmers, runners, and weightlifters. However, more studies are needed to determine the effectiveness of melatonin as a ergogenic aid.
If you are interested in using melatonin as a sleep aid, take between 1 and 5 mg 30-60 minutes before bedtime. The dosage should be adjusted depending on the individual. For normal sleep, a low dose of 0.5 mg can be effective.
A higher dose of 5 mg may be necessary to treat sleep disorders such as jet lag and shift-work disorder. It may take 3-7 days for melatonin to reach maximum effectiveness, so give it a few days before deciding if it’s effective or not.
Melatonin is generally safe, but you may experience some side effects such as headache, stomachache, nausea, and nightmares. Do not drive or operate heavy machinery for at least 4 hours after taking melatonin. Since it can also impair memory, do not take it just before an important meeting or exam.
Written by Michael Jensen MS, RD, CISSN, CJA
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