There is a very small but important gland in the brain called the pineal gland. This gland produces an assortment of hormones that control various bodily functions including a hormone called Melatonin. As the day progresses, the amount of melatonin in the blood fluctuates. This cyclical fluctuation plays an important role in regulating bodily functions that follow a similar cyclical pattern. As the melatonin levels increase and decrease, melatonin receptors become more or less active controlling how our bodies react to certain situation that arise during the day.
The regular secretion of melatonin can also be altered by external stimuli such as light and dark. Melatonin is often referred to as the “hormone of darkness” because melatonin secretion is increased in the absence of light. In animals, this is important to both nocturnal (active at night) and diurnal (active during the day) animals because it controls when they are naturally active. Although humans don’t have to abide by day or night hunting schedules, melatonin is also important in regulating our sleep cycle.
You can find melatonin as a dietary supplement in the United States quite easily whereas its availability is somewhat limited in other parts of the world. In foreign countries where it is available, you often have to have a prescription, usually for insomnia.
The discovery of melatonin dates back to around 1917 but the properties and function of the hormone were not fully understood until much later. Researchers in the 1950’s discovered that melatonin exhibited what is known as a circadian rhythm in humans. That meant that the level of the hormone secreted by the pineal gland followed a natural cycle that closely followed our 24 hour day. These types of cycles are common in humans, the most familiar of which is our sleep cycle. Our bodies are naturally accustomed to being awake for a certain amount of time and then sleeping for a certain amount of time without us having to think about it. The cyclical levels of melatonin in the body mirror that same cycle.
Melatonin secreted when we are supposed to be sleeping or when it’s dark activates certain receptors that signal a feeling of being tired. Melatonin supplementation would then make sense for people with insomnia. Increased activation of melatonin receptors would help individuals sleep who, for one reason or another, find it difficult to do so.
Prescription sleep aids function by altering the delicate hormonal balance in our brains or by introducing foreign sedative agents. That often results in unwanted side effects. By contrast, melatonin is found naturally in our bodies as well as in several plants and animals. A melatonin supplement derived from natural sources would not have to manipulate the fragile chemistry of the body; it would simply introduce a greater amount of something your body is lacking. With the amount of unnatural light in our lives and the crazy schedules we keep, regulating our melatonin levels could be the key to more regular sleep.