Melatonin is a natural hormone produced by the pineal gland - a small, pea-shaped gland in the center of the brain. It is crucial to our sleep-wake cycle and is sometimes referred to as the “sleep hormone”. The production of the molecule depends on the brightness of our environment. More is produced in the dark, making us sleepy, while production decreases in bright light, keeping us awake and alert. In many aspects it is the antagonist of cortisol.
The primary function is Regulation of sleep. The vital substance signals to our body when it is time to sleep and wake up. This is closely linked to our circadian rhythm , the internal clock that determines our daily cycle of sleep and wakefulness. Melatonin plays an essential role in setting this rhythm based on the light we are exposed to.
What influences our melatonin production?
Lifestyle changes can affect the body's production. For example, a change in sleeping habits, diet, or light exposure can affect melatonin levels in the body. The blue light, which is often emitted by electronic devices such as smartphones and computers, can inhibit melatonin production making it difficult to fall asleep. Therefore, it is recommended to reduce exposure to blue light in the evening hours to ensure good sleep quality.
Where is melatonin found?
In addition to dietary supplements, the molecule can also be contained in certain foods. These include fruits and vegetables such as cherries, corn, asparagus, tomatoes, pomegranates, olives, grapes, broccoli and cucumbers. Some grains, nuts and seeds such as rice, barley, oats, walnuts and flaxseed also contain higher amounts. It is also found in some proteins, including poultry, fish and dairy products. The melatonin concentration is particularly high in sour cherries of the Montmorency variety, which you will find in some sleep supplements .
As already mentioned, our brain also produces melatonin. This starts with the amino acid tryptophan. It is converted into another compound called 5-hydroxytryptophan with the help of enzymes. This is then converted into serotonin, a neurotransmitter associated with feelings of well-being and happiness. When it gets dark, the serotonin in the pineal gland is converted into melatonin. The pineal gland then releases the sleep hormone into the bloodstream.
Did you know?
Our intestinal bacteria are crucially involved in the production of serotonin . Entire 90% of the hormone is in the intestine! The starting point here is also the amino acid tryptophan, which can be converted by our microbiome via three different metabolic pathways. If our microbiome becomes out of balance (dysbiosis), production can be impaired. Probiotics and prebiotics can help in this case.
Health effects of melatonin
Sleep quality and duration
In a double-blind study the effectiveness of melatonin in improving sleep was examined studied in cancer patients with insomnia. 50 patients received either 3 mg melatonin or a placebo orally daily for 14 days. The results showed significant differences in favor of melatonin treatment with regard to clinically relevant improvements in insomnia.
A large meta-analysis examined the effects of melatonin on primary sleep disorders using 19 studies with 1,683 participants. Compared to placebo it significantly reduced the time to fall asleep and increased total sleep time. Long-term studies and studies with higher doses showed greater effects in reducing sleep onset latency and increasing total sleep time. Overall sleep quality improved significantly in subjects taking melatonin compared to placebo. The results suggest that in the long term the molecule reduces sleep onset latency, increases total sleep time and improves overall sleep quality.
Gastroesophageal reflux disease
This study examined the role of exogenous melatonin in the treatment of gastroesophageal reflux disease (GERD) in 36 people. Participants were divided into four groups and treated with melatonin alone, an antacid alone, or a combination of both for 4 and 8 weeks. The results showed that the "sleep hormone", alone or in combination with the PPI, helped improve reflux disease, with the acid blocker alone being more effective compared to melatonin monotherapy. The researchers' conclusion: Melatonin is a promising therapeutic agent for the treatment of GERD, but further studies are needed to confirm the effectiveness and long-term safety of melatonin.
Human growth hormone
In a double-blind, randomized crossover study the influence of exogenous melatonin in different doses (0.05 mg, 0.5 mg or 5 .0 mg) for the release of pituitary hormones in eight healthy male volunteers. The results showed that melatonin caused dose-dependent changes in circulating concentrations of oxytocin and vasopressin, with a dose of 0.5 mg being stimulatory and 5.0 mg being inhibitory. These two doses stimulated the release of growth hormone.
Various forms of melatonin as a supplement
The sleep hormone is available in various forms, including tablets, capsules, drops and sprays. The choice of shape often depends on personal preferences and individual needs. Melatonin sprays are sometimes preferred because they allow for faster absorption, while tablets and capsules can offer a slower release of the hormone.
Side effects of melatonin
In general, the sleep hormone is considered safe. However, side effects may occur when taking melatonin supplements, including headaches, dizziness, nausea, and drowsiness. There are also concerns about possible interactions with other medications, particularly blood-thinning medications and antidepressants. It is important to speak to a doctor before taking melatonin, especially if you are taking other medications or have certain health conditions.
Is an overdose possible?
An overdose of melatonin can lead to various unwanted side effects, including next-day sleepiness, confusion, headache, dizziness, stomach upset, and even hallucinations. An overdose of melatonin can lead to unpredictable reactions, especially in children, as their organism can react more sensitively to hormonal changes. It is therefore important not to exceed the recommended dosage.
Can the sleep hormone be addictive?
As far as being addictive, melatonin is generally not addictive because it is a hormone and not a substance that causes a euphoric or rewarding feeling. However, misusing melatonin to treat sleep disorders can cause the body to become habituated and dependent on it. It is important to take melatonin only as directed and not to abuse it as a long-term solution to sleep problems. If sleep problems persist, it is advisable to treat the underlying causes and consider alternative treatment methods.
Melatonin gummy bears: A sweet alternative?
Melatonin gummies are a relatively new form of melatonin supplement that are particularly popular with children and people with swallowing difficulties. These gummies contain a specific amount of the sleep hormone per serving, providing a pleasant and easy-to-dose option for those who have difficulty taking traditional tablets.
How dangerous are the gummy bears?
Pediatricians have increasingly expressed concerns about the use of melatonin gummies in children. These concerns relate to the potential overdose of the sleep hormone as well as the long-term effects on children's health and development. Because the dosage of melatonin in gummies often cannot be accurately controlled and children tend to consume more than the recommended amount, there is a risk of unwanted side effects such as next-day sleepiness, mood swings, and possibly even hormonal imbalances. Pediatricians therefore recommend treating the use of melatonin gummies in children with caution and considering alternative approaches to treating sleep disorders, especially with long-term use. It is advisable to consult a pediatrician before using melatonin in children to ensure appropriate dosage and use.
Melatonin & Longevity
Studies have shown that melatonin may play a role in extending lifespan and health as we age. A 2017 study uncovered a link between melatonin and cellular health, which contributes to longevity. It was about the Hallmarks of Aging, and more specifically about the function of the mitochondria, the power plants of our cells. These become increasingly weaker with age, resulting in mitochondrial dysfunction. The NAD levels decrease and this slows down energy metabolism. You can find out more about this in our detailed NAD article.
What happens as you get older?
As you age, several factors can contribute to lower melatonin levels. One of the main reasons is the natural aging process, which can be associated with changes in the functioning of the pineal gland, the main organ for melatonin production in the body. As we age, the number and function of pineal cells decreases, which can lead to reduced production of melatonin.
In addition, age-related changes in sleep patterns and light exposure can influence melatonin production. Older people tend to have less deep sleep and may be more susceptible to sleep disorders such as insomnia. This can lead to decreased melatonin production because melatonin is normally released during sleep.
In addition, age-related diseases such as diabetes, heart disease and neurological disorders can also affect melatonin production. These diseases can directly affect the function of the pineal gland or affect other factors in the body that regulate melatonin production.
Another important aspect is exposure to light. Older people may spend less time outdoors and be exposed to less sunlight, which can affect the natural synthesis of melatonin, as sunlight is an important stimulus for the production of this hormone.
Therefore, it is believed that maintaining high levels of melatonin in the body can help delay or minimize the negative effects of aging.
