What is melatonin?
Melatonin is actually a natural hormone produced by the pineal gland located in top of the diencephalon. That’s why the side effects are minimal. The pineal gland controls the day-night rhythm of the brain and is highly affected by daylight. Actually it is more like affected by darkness. Since at night melatonin secretion is significantly increased from the pinealocytes.
The pineal gland is controlled by the suprachiasmatic nucleus located in the hypothalamus. Suprachiasmatic nucleus is the part of the brain which receives the signals from different receptors located in our bodies. These are mainly in our eyes, and controls the circadian rhythms.
The impulses coming from the retina make the suprachiasmatic nucleus stimulate the pineal gland and so the pinealocytes produce melatonin. So, what this means is that the more the light we have coming in our eyes, the less melatonin håndkøb is produced. This is one of the reasons why people living in the parts of the world where there is more daylight are perkier during the days. Their eyes get more light and their pinealocytes produce more melatonin.
Although as a down side they might have trouble getting sleep during the night if it is light in the late hours. This is usually not a problem because night falls very dark in the southern hemisphere and usually quite early. The day-night rhythm is much more distinct, and our bodies can react to it much easier.
Melatonin chemically is very hydrophobic which means that it can penetrate the cell membrane very easily. That means that melatonin has a lot of effects on multiple tissues and it is not only meant for sleeping problems. In the animal kingdom melatonin has a lot of effects on the sexual functions of different species. In some animals it increases sexual activity but in other, like sheep for example, it decreases them.
Controlling your hormone levels
Since melatonin can travel to all the tissues it has all kinds of effects on different glans and it also controls many different hormone levels during sleep. All these hormonal levels are somehow linked to circadian rhythms, so melatonin really is a sleeping regulator.
The most important hormone levels that melatonin controls are growth hormone, prolactin, thyroid, corticosteroids. These are all secreted in large pulses which are related to the hour of the day. As mentioned earlier growth hormone has the biggest blood concentration during the first few hours of sleep and it is controlled partly by melatonin.
Corticosteroids are highest in our blood during the last hours of sleep which points to us to the direction that decreasing melatonin levels have a corticosteroid releasing function.
Even though our bodies rely much on the planets day-night rhythm and melatonin secretion is directly related to the amount of light our light receptors in our eyes receive, we would still live in circadian rhythms if we lived in constant darkness.
Although then melatonin secretion would be higher, like with people living in the northern parts of the world where the light time during the day is much shorter than in the southern parts. Our normal nychthemeron actually is a bit over 24 hours which means that maybe in some part of the evolution of the human race the days have been longer. This nychthemeron then is fine-tuned by the sun providing decreases and increases in melatonin secretion.
Melatonin sleep aids are just helping us get a grip of the nychthemeron rhythm. If we chose to live in the dark our bodies would still live in a day-night rhythm which would be slightly longer than 24 hours and the changes in hormone production would not be so obvious, but rather there would be just slight changes in the hormone levels. That is why you would probably be a little sleepy all the time.
How is melatonin used?
As the suprachiasmatic nucleus is controlled by day-night rhythms, bright light treatments are used to lessen morning tiredness and prevent or even help with seasonal depression during the darker winter time especially in the northern parts of the planet. Melatonin (N-acetyl-5-methoxytryptamine) usually helps with problems like this as well.
Because your body has trouble in finding out when is the day and when is the night it cannot produce such regular bursts of melatonin. The receptors from your eyes do not send so many signals from the daylight which is usually only for a very short time. That is why your body basically gets mixed and either it produces too much sleep hormones like melatonin, or it does not produce them enough. Either constant drowsiness or sleeping problems is the result.
When people feel fatigue all the time they tend to resort to different beverages like energy drinks and coffee. That helps them stay awake during the day, but it also affects the sleeping time. Because of a busy lifestyle combined with improper use of caffeinated beverages sleeping problems occur. Melatonin sleeping pills can usually be used for problems like this because it makes the sleep deeper and through that pathway it decreases the daytime sleepiness.
Melatonin lowers the body temperature which mainly means that it slows down your body metabolism which makes it easier to relax. When you are tired you usually feel a bit cold. This might have some relation to the fact that warming the suprachiasmatic nucleus increases drowsiness and sleepiness. It might be due to increased melatonin secretion and it might be a natural way of trying to lower your body temperature since it has an effect to the total body temperature.
Nowadays melatonin is being used to control circadian rhythms, as an over the counter sleep aid. In US it is sold as a natural supplement and a natural remedy for insomnia. It might have some very positive effects on insomnia especially in the milder cases. People who work in multiple shifts and have to change their sleeping habits constantly might benefit from melatonin supplementation and gain deeper sleep faster. Since melatonin affects the day-night-rhythms it helps you to go to sleep earlier than usual.
Melatonin for jet lag
Melatonin can also be used to treat jet lag. When you travel through many time zones your body clock does not adjust with the change. As an example, your body might think it is time go to bed when it is as late as 2:00am and you have been trying to get sleep from 9:00pm. This might happen when moving through 3-5-time zones or even more.
Melatonin can be taken from as low doses as 1mg 30-60min prior the wanted sleeping time. Doses may vary independently, and there are supplements that contain as high as 3mg per pill. Although much smaller amounts have been reported to have a good effect. Melatonin has also been developed in to melatonin sublingual tablets that are easily administered and is fastly absorbed below the tongue.
Melatonin side effects
Differently from the more traditional sleeping pills like benzodiazepines, melatonin side effects have not been shown to cause morning fatigue au contraire it has positive effects on sleep quality and may help people wake up perkier than normally. Melatonin supplementation has been shown to have an increase in vivid dreaming which might point in to the direction that it increases REM sleep.
Differently from other sleep aids melatonin usually does not have to be used multiple nights. Not that you should use regular sleep aids constantly, but you tend to get comfortable in taking a pill at night and falling asleep. The effect of the melatonin is somewhat unnoticeable. You do notice the effect but with melatonin it does not hit you like it does with regular sleep aids. Melatonin helps you relax and provides calm for your nerves which eventually allow you to get in a such relaxed situation that it is possible to fall asleep.
Circadian rhythm disorders
Melatonin may be used to treat circadian rhythm disorders, ADHD, increase fertility in perimenopausal women, headaches and even mood disorders and gallbladder stones. Melatonin has been shown to cause very little side effects even in quite long studies and therefore it is sold as a over the counter sleep aid. Therefore, it might be considered as a relatively safe natural remedy for sleeping disorders and help your trouble with sleeping.
Does sleeping during the day affect hormone levels?
There really has not been that much study whether sleeping during the day affect hormone levels, but there can be made some educated guesses. Since most of our hormonal functions are cycles are controlled by our sleeping rhythms some hormonal levels like testosterone and other androgen levels may be affected.
Also, even melatonin levels are affected because you get that time in the day when your eyes are closed, and your eyes don’t receive any stimulus from the daylight. This as mentioned before activates the pinacocytes to produce the natural hormone melatonin. That is why melatonin side effects are so rarely seen: It is a natural hormone. The average daily dose of Melatonin ranges from 1ng to 5mg.
Melatonin supplements and diabetes
For now, there has been some research data that shows that the use of synthetic melatonin is causing people with type 1 diabetes to have elevated blood glucose. For now, there is no sane reason why this is happening and if you have diabetes it is advised to take this in to account
There are products that have recently hit the markets like melatonin sleep aid. Something like this should be great since it is all-natural ingredients. Which are especially designed to help you to get back to the natural rhythm of your sleeping patterns.
It is not as artificial as taking a sleeping pill, but instead it is just like with all the other melatonin supplements. It is a natural hormone. You should not expect to get tremendous results. But I have heard of people who have found help from these products. It is always advised to keep in mind that we are all individuals, and that sometimes we can’t know beforehand how some product will work for a specific individual.