Melatonin: Should You Take It at Night?
Melatonin is believed to help with insomnia, headaches, and depression. Here’s what the science says
Melatonin is the most common sleep drug that can be found in pharmacies around the world and as a dietary supplement: it is available in tablets, dragées, capsules, drops, and even in the form of gummy bears. It is a natural remedy in the sense that melatonin from medical preparations is no different from the one produced by the body itself. And it really triggers sleep. But does it follow that a melatonin pill will help you get rid of insomnia? It is not that simple.
Melatonin: what is it?
First of all, it is a very ancient molecule: hundreds of millions of years ago, living organisms learned how to synthesize melatonin, and since then it has been used for a variety of purposes by animals and even plants.
The most well-known role of this substance in animals is to tell the body when it’s time for sleep. It would seem that it could be simpler: we already see that it is getting dark. But we see this with ordinary receptors: cones and rods, which allow us to distinguish colors, shapes, movement, that is, they give vision. Our brain receives information about the change of day and night from other receptors, which are also located in the eyes, but are tuned to only one type of signal: is there light around or not. From these receptors, information enters a special part of the brain, which informs the rest of the organs about the change in the time of day through the release of the signal molecule melatonin. Its concentration in the blood increases with the onset of darkness, and when it gets light, the secretion of the “sleep hormone” stops. The body understands that the day has come, and disturbs the nervous system. We are waking up.
So, through external signals, in this case, the level of lighting, we correct our circadian rhythms, that is, the ability inherent in the cells themselves to reduce or start activity. As experiments on survival in complete darkness have shown, without an external signal, the body will continue to work in accordance with internal circadian rhythms, but the day will gradually shift forward, since our “internal clock” does not fully correspond to the 24-hour regime.
Melatonin is synthesized not only in the brain: it is produced by the cells of the liver, intestines, eyes and other organs. This substance is involved in many vital processes: it works as an antioxidant, affects the production of digestive hormones and sex hormones. The scope of melatonin in medicine can be very wide. But first things first.
Melatonin as a drug
Melatonin has been credited with treating insomnia and headaches, alleviating symptoms of depression and ADHD, promoting weight loss, and boosting immunity. Here’s what research says about these effects.
- Helps improve sleep? Yes, if the problem is in the circadian rhythm. Melatonin’s job is to keep the body’s “internal clock” running. Therefore, it is effective when the cause of sleep problems is circadian rhythm disturbances. Example: late sleep syndrome, when a person cannot fall asleep until late at night, wakes up early in the morning with difficulty, but sleeps perfectly well when there is no need to rush anywhere - just lies down and gets up later. Another example: changing time zones. The Cochrane Review recommends melatonin for all adults flying across five or more time zones. And for those who cross two or four time zones, he also advises to drink an additive, but with the condition: if you can’t fall asleep yourself.
- Treats insomnia? Perhaps, but not a fact. If insomnia was caused not by a malfunction of the “internal clock”, but by some other reason, the chances that melatonin will help are much less. This hormone does not cause the body to fall asleep, but only gives a signal that it is time to sleep. But just reminding the body may not be enough if, for example, anxiety activates the nervous system. Research says melatonin helps people with secondary insomnia (that is, caused by other disorders, including mental ones) sleep 24 minutes longer, but how good the sleep is an open question. The American Academy of Sleep Medicine considers melatonin in combination with cognitive behavioral therapy to be the most promising treatment for chronic insomnia (three or more weeks of trouble sleeping), but there is a lack of long-term data. However, melatonin has an undeniable plus: it is much safer than classic sleeping pills and, unlike them, does not change brain activity during sleep, does not cause withdrawal symptoms, and does not increase insomnia if you stop drinking it.
- Required for admission after 55 years? Not sure, but might be useful. As we age, the natural production of melatonin in the brain decreases. Taking the supplement after 55-60 years of age improves the quality of sleep, increases morning alertness and quality of life in general. At the same time, it does not cause dangerous side effects, such as a high risk of cognitive impairment and does not increase the risk of falls with fractures, unlike classic sleeping pills. But at this age, a person is more likely to take drugs that increase or decrease the effect of melatonin, which is fraught with additional risks. Therefore, before taking it, you should discuss with your doctor how safe it is.
- Prevents headaches? It is not yet clear. Tension headaches are associated with stress, pain and tension in the neck or facial muscles, or visual strain. But also with sleep disorders. Melatonin has the potential to prevent them. But, alas, there are few high-quality studies that would prove this. The same goes for migraine prevention.
- Treats depression? It just prevents. Seasonal affective disorder (aka seasonal depression) usually occurs in the fall and winter. This may be due to changes in the circadian rhythm due to the fact that there is too little light during these seasons. It is logical to assume that since melatonin regulates the circadian rhythm, its intake will help to stop seasonal depression. There are small studies in which daily melatonin supplementation actually alleviated the symptoms at the time of the flare-up. But the authors of a review of such studies concluded that melatonin does not help with seasonal depression, anxiety disorder, and bipolar disorder. But prophylactic administration before the onset of seasonal depression can be justified: the disorder will not appear or will pass in a mild form.
- Helps to lose weight? Yes, but with a condition. Melatonin is intricately linked to weight. First, it activates special fat cells - brown and beige fat, which regulate heat exchange and calorie burning. The more brown and beige fat cells in the body, the better weight control. Second, melatonin metabolism is linked to the hormones’ cortisol (stress response), ghrelin (hunger), and leptin (satiation). At the same time, obese people have high levels of cortisol and ghrelin, and low levels of leptin. All of this leads scientists to believe that melatonin supplements may stimulate weight loss. Small experiments on animals and humans give good results. For example, in one study shift workers with sleep disorders took melatonin, and their body weight, BMI, waist and hip circumference decreased - without any changes in diet or lifestyle. But there is an important condition: in the participants of such experiments, the natural level of melatonin was already low, and sleep was poor. Not the fact that with healthy supplements will work the same way.
- Boosts immunity? Yes, but there are nuances. Melatonin interacts with the immune system in a complex way, as it acts on both innate and specific responses of the immune system. In the latter capacity, it works as an immunomodulator: it helps to make the immune response faster and more effective. But if the immune system already reacts strongly to the threat (this happens with septic shock), then melatonin can act exactly the opposite: suppress inflammation. Melatonin also functions as an antioxidant, counteracting oxidative stress that damages our cells. Therefore, it is considered as a medicine for premature babies who require resuscitation with oxygen therapy. Oxygen causes oxidative stress, but melatonin helps offset its effects. It all sounds like as if taking melatonin would somehow benefit the immune system. But the truth is that scientists still have a poor understanding of how the supplement affects the immune system. Therefore, it makes no sense to take it for the sake of improving immunity.
- Helps prevent and treat covid? It’s not clear yet. According to a Cleveland Clinic study, taking melatonin reduces the likelihood of getting sick by 28% due to the anti-inflammatory and antioxidant properties of the hormone. Scientists also suggest that melatonin may help in the treatment. But there is no data that would prove that melatonin really protects and treats covid. The authors of another interesting study concluded that taking melatonin two weeks before vaccination will improve sleep, and the vaccine will be given when the immune system is in the best condition. And if you take melatonin a month after vaccination, the immune response will be stronger, and immunity will last longer. But it is not exactly. Melatonin can suppressan overactive immune response in covid, so could potentially make the vaccine less effective.
The therapeutic effect of melatonin, with the exception of correcting circadian rhythms, is still doubtful, because many studies have been conducted on animals, the sample in human studies is small, and often they do not exclude the influence of other factors.
Risks when taking melatonin
Melatonin is considered safe for short-term use, such as to restore sleep patterns. Even taking single extreme doses is unlikely to cause harm. There is not enough data on long-term use to consider it completely safe, but there are few risks. Here are the ones to keep in mind.
- Melatonin has side effects. Headache, dizziness, daytime sleepiness, and nausea are rare but do occur. They may be an individual reaction or the result of too much dosage (above 3 mg). Melatonin also inevitably causes drowsiness immediately after taking it, so it is best to avoid driving or operating machinery for five hours after taking the supplement.
- Melatonin can interfere with how medicines work. The list of drugs that should not be taken with a supplement is quite long. Anticoagulants, antiplatelet drugs, and any supplements that reduce blood clotting when combined with melatonin increase the risk of bleeding. Antidepressants and hormonal contraceptives cause excessive sleepiness and may exacerbate side effects. Diabetes medications may not work as well because melatonin reduces insulin sensitivity and production. Anticonvulsants and immunosuppressants also work worse. So if you are taking medication, you should consult your doctor before buying melatonin.
- The composition of the supplement does not always correspond to the label. The production of nutritional supplements is not regulated as strictly as medicines. As a result, they may not contain melatonin at all, or may contain less than what is listed on the package. In 2017, researchers tested 31 melatonin supplements and found that the melatonin content was not labelled, within 10% of what was stated on the label, in more than 71% of the supplements. 26% of supplements also contained serotonin, the excess of which is fraught with serotonin syndrome, a rare but dangerous toxic reaction.
- The dosage is not so easy to find. The brain produces less than 0.1 g of melatonin per night. In supplements, melatonin is usually much higher: 2–12 mg. This number seems excessive. Especially in the context of studies in which melatonin reduced insulin sensitivity and production.
In what form and how to take melatonin
Melatonin comes in two formats: regular and extended release. The usual dissolves as soon as you take the pill, and instantly enters the bloodstream. After four hours, it is almost 90% processed by the body. Delayed release supplements dissolve more slowly. Their action is more like natural melatonin, which is produced in the body gradually during the night.
If the problem is one-time (jet lag that caused a flight across several time zones, for example), then a regular supplement will do. In other cases, it is better to take melatonin with prolonged action. And not an additive, but a drug that has passed quality control and examination. This gives more confidence that its composition and dosage are really the same as the manufacturer assures. But before buying, you will need to go to the doctor: melatonin medicine is not sold freely, but by prescription.
Melatonin with immediate action is taken 30 minutes before bedtime, and with prolonged action - one to two hours before bedtime. With dosage, everything is not so clear: studies are testing different options, since the effect depends on the type of problem and the individual characteristics of the person’s metabolism. One study found that plasma levels of melatonin in healthy young adults taking a 0.1–0.3 mg supplement reached natural levels. But a dose above 1 mg per day can already increase the concentration of melatonin so that it exceeds physiological.
The recommended dose of the supplement, regardless of the purpose for which you take it, is no more than 3 mg per day: if you drink more, you are likely to experience daytime sleepiness and other side effects. If sleep patterns are only slightly disturbed by jet lag or short-term insomnia occurs, you can start at 0.1 mg and gradually increase to 1 mg until sleep returns to normal. And in the case of chronic insomnia, when a low dose may not work, it is better to consult a doctor and discuss with him whether to try melatonin or look for another solution.
