Ever since the ancient Greeks first took note of a tiny structure in the brain that they called the pineal gland, people have been wondering just what it does.
Physician and medical researcher Galen, doubting that anything as small as a grain of rice could have much functional significance, assumed it simply provided a little structural support, like a bolt or rivet.
Centuries later, French philosopher René Descartes viewed it through a mystical lens, asserting that it contained the seat of the soul.
But it wasnʼt until 1958 that science identified the pineal gland as an endocrine organ — one that produces hormones, or chemical messengers, that help coordinate the bodyʼs functions. And the glandʼs hormone, melatonin, is kind of a big deal.
These days, melatonin is one of the worldʼs best-selling supplements, widely recognized for its role in regulating sleep. It helps to orchestrate your circadian rhythms (the internal biological clocks that tell you to get hungry at breakfast time and doze off during that Zoom call at 2 pm). Melatonin production waxes and wanes depending on your exposure to light and dark.
But what exactly is melatonin? Is sleepiness its only trick, or does it affect your health beyond getting your zzzʼs? What encourages your body to make it and release it? And is it a good idea to get it from food, or from supplements?
What Is Melatonin?
Chemists know melatonin as 5 methoxy-N-acetyltryptamine. Its main function is to regulate sleep and wakefulness. It does this by interacting with the retinas of the eyes and a part of the hypothalamus that sounds like it belongs in a superhero movie: the suprachiasmatic nucleus.
While melatonin is the main hormone secreted by the pineal gland, itʼs also produced in small amounts in the eyes, bone marrow, blood platelets, skin, brain tissue, and the gastrointestinal tract (cue the Beach Boysʼ “I Get Around”). Most of the melatonin in your body lives in your intestinal tract.
Your pineal gland synthesizes melatonin from the amino acid tryptophan (thatʼs where the “tryp” in the hormoneʼs chemical name comes from) via a precursor hormone, serotonin.
I had to read many scientific sentences like, “The pineal gland secretes melatonin at night mainly driven by adrenergic sympathetic inputs” to be able to tell you that melatonin synthesis and secretion are enhanced by darkness and inhibited by light.
Melatonin is kind of like the conductor of the bodyʼs orchestra, keeping the internal organs and processes synchronized via circadian rhythms. This helps the body adapt to its environment and to the time of day.
But melatonin is more than an alarm clock in the morning and a cup of chamomile tea at night; it also acts as an antioxidant in the body, helping fight off inflammation and free radicals that cause disease.
The Health Benefits of Melatonin
Melatonin contributes to health across a bunch of domains. These include helping you sleep well (and wake up feeling refreshed), aiding your immune system, protecting your nervous system and brain from degeneration, fighting cancer, boosting heart health, and supporting reproductive health.
We know that endogenous melatonin (that is, the stuff your body produces) is critical for many bodily functions. But most of the research done on melatonin has used supplements because theyʼre so much easier to study. So letʼs take a look at what the supplement-related studies tell us about melatoninʼs benefits. Then we can explore how to get it into your body.
Melatonin and Sleep
Melatonin is most famous for helping people who struggle to get enough shut-eye. And thereʼs plenty of research to validate its efficacy.
A 2021 meta-analysis of 6 studies of cancer patients with insomnia found that supplementing with melatonin just before bedtime reduced insomnia and increased sleep quality.
A 2022 study of older adults with chronic insomnia also found that melatonin supplements increased total sleep time and sleep quality compared to a placebo.
People who take long east-west routes on airplanes can suffer from jet lag, where the body has trouble adapting to the new light/dark schedule and wants to go for a jog at 2 am and fall asleep on top of a bowl of soup at noon. Research has shown that melatonin can help adjust your internal body clock to overcome jet lag. By taking melatonin at specific times, ideally tied to your desired bedtime, you can shift your body clock earlier or later, which can help match your circadian rhythm with your location on the planet.
Similarly, melatonin has been shown to reduce insomnia in people who work night shifts.
Melatonin and the Immune System
Biochemists have established that melatonin, especially in combination with vitamin C, can protect cells from harm from reactive oxygen species (types of free radicals).
A 2023 meta-analysis of 11 clinical trials found that melatonin supplementation improved the health of people with COVID-19. They spent less time in the hospital than those given a placebo and showed lower levels of inflammation. In the highest quality studies, patients who took melatonin also had a much lower death rate.
Melatonin and the Brain
With Alzheimerʼs disease, drops in melatonin levels that accompany aging might be linked to the development of the disease. Recent research has shown that melatonin can help protect the brain by encouraging the production of proteins that prevent harmful amyloids from forming.
And a 2023 study using rodents (our view on the use of animals in medical research is here) suggests that melatonin supplementation may improve memory and lower levels of harmful proteins in the brain.
Melatonin has also been found to be beneficial for people suffering from multiple sclerosis (MS). But this is where things get a wee bit complicated. Researchers have also found that living closer to the earthʼs poles, where there is less sunlight during the long winters, increases melatonin and decreases vitamin D levels. And this combination can exacerbate MS by promoting inflammation and demyelination.
So it seems that timing might be key. We want melatonin at night when we are sleeping — but not during the day, when weʼre active. As a result, in regions of the world where there’s a lot of light pollution, it may be harder for peopleʼs melatonin levels to modulate optimally between day and night.
Melatonin and Cancer
Research has shown that melatonin can help fight various types of cancer, both in lab settings and in living organisms. It can slow or stop the growth of cancer cells, reduce the size of tumors and prevent them from spreading, lessen side effects of chemo- and radiotherapy, lower the resistance of cancer cells to chemotherapy, and boost the effectiveness of some cancer therapies.
Melatonin appears to fight cancer through several mechanisms. It can interfere with the way cancer cells use energy. It impacts various metabolic processes such as glucose uptake, glycolysis (a way cells break down glucose for energy), and other metabolic pathways. Melatonin also affects lipid metabolism and influences important molecules involved in cancer progression.
Melatonin and Cardiovascular Disease
Melatonin has also shown promise in preventing heart problems, particularly those related to blocked arteries. Research shows that the hormone can reduce levels of LDL (“bad”) cholesterol and triglycerides, improve the function of blood vessel linings, reduce inflammation, suppress harmful immune responses, and protect cells from damage.
Melatonin also prevents the growth of muscle cells in arteries, which can worsen blockages, and strengthens the protective cap on plaques in arteries to prevent ruptures, which can cause strokes.
Thereʼs also preliminary research suggesting that melatonin can help with arrhythmias (irregular heartbeat) and high blood pressure.
Melatonin and Fertility
Melatonin may also improve reproductive health in males and females. A 2023 review article found that antioxidants like melatonin can protect male fertility from the harmful effects of oxidative stress by improving semen quality.
Melatonin can also improve the quality of womenʼs eggs and support early embryonic development. It does this by slowing down the aging process of the ovaries, keeping them healthier for longer, and helping to manage oxidative stress in women with polycystic ovary syndrome (PCOS), improving their egg quality.
Melatonin can also help women who are trying to get pregnant through in vitro fertilization. It helps protect eggs during the freezing and thawing process and improves the quality of eggs that are matured outside the body.
Ways to Increase Melatonin Naturally
The scientific studies on melatonin have mostly looked at supplementation because itʼs easier to control and measure. But we also know there are ways to increase your melatonin levels through more natural means.
Light Regulation
One of melatoninʼs nicknames is “the darkness molecule.” (I would have loved to have been at the meeting of endocrinologists where “Plenary Session 3A: Selecting a Nickname for Melatonin” was on the agenda.)
But thereʼs a paradox: while melatonin is indeed released during periods of darkness, the body also needs sufficient light during the day for the pineal gland to produce any — at least 1,000 lux (a measure of light intensity) at eye level.
This level of lighting is simply not achievable in most indoor settings, including offices and industrial areas. In fact, people who work indoors during the day experience light intensities 40–200 times lower than natural outdoor light.
(If youʼre curious about the lightning in your indoor spaces, there are several smartphone apps that use the phoneʼs camera to measure and report lux levels.)
Itʼs not just inadequate daytime lighting that messes with melatonin production. Exposure to electronic screens and LED light bulbs at night, and especially in the hours right before bedtime, can also suppress it. The blue wavelengths produced by those devices (roughly 460–480 nanometers) tell the pineal gland not to secrete melatonin.
Thatʼs why most sleep experts recommend staying off electronics or using their “night shift” mode starting at least two hours before bed.
Maintaining a Regular Schedule
Melatonin interacts with your circadian rhythm, which aligns your bodyʼs processes and functions with the environment — specifically, hours of darkness and light. An irregular schedule, especially one that involves sleeping at different times on different days, can interfere with getting good quality and quantity of sleep.
People who stick to one schedule during the work week and then shift it by several hours on weekends (staying up late and sleeping in, for example) can suffer from whatʼs known as “social jet lag.” This is a lot like regular jet lag, but it at least doesnʼt involve screaming toddlers in the row behind you or waiting at baggage claim carousels for bags that never arrive.
Shift work can also alter melatonin production, as can varying the timing of your meals. Even exercising late in the day can delay the release of melatonin. I imagine your body is thinking, “Am I running away from a tiger right now? Iʼd better not start releasing sleepy-time chemicals into my system just in case.”
Maintaining a regular schedule and, in particular, trying to go to bed at the same time every day can help keep your melatonin levels optimal.
Diet and Melatonin Production
In addition to the timing of your meals, what you eat can also affect melatonin production. Consuming caffeine and alcohol at night can suppress melatonin, which, in turn, may inhibit the release of a chemical called adenosine, which is directly responsible for your “sleep drive.”
Chronic alcohol consumption can change the way your body produces and uses melatonin in two ways: it can delay the natural rise in melatonin that occurs at night, and it can decrease overall melatonin levels.
Eating foods that contain melatonin can increase serum levels in your body. But that doesnʼt mean those foods will make you sleepy. Even after you consume them, your body needs darkness to increase melatonin synthesis and secretion. Light, as weʼve seen, inhibits melatonin.
So as long as youʼre not sitting in the dark all day, eating foods that contain melatonin during the day is unlikely to make you significantly more sleepy.
At night, on the other hand, these foods may help with sleep by working with your circadian rhythm and increasing already heightened levels.
Melatonin-Rich Foods
So what are some foods rich in melatonin?
The foods highest in melatonin are those from animals, with eggs, salmon, and milk having the highest concentrations. (Fun fact: human breast milk varies in melatonin content by time of day — lots at night, and virtually none during daylight hours.)
Turkey is often credited for causing post-Thanksgiving dinner sleepiness, and itʼs true that turkey does contain the amino acid tryptophan, which is a melatonin precursor. But all protein-containing foods have some level of tryptophan, so itʼs more likely that itʼs the total amount of food consumed at Thanksgiving that makes people drowsy, rather than some specific quality of turkey meat.
Among plant-based foods, nuts take the prize for the highest amounts of melatonin. Pistachios and walnuts, in particular, win gold and silver. You can also find melatonin in whole grains (wheat, barley, oats, pigmented rice), mushrooms, legumes (germinating them before cooking or eating increases the concentration), fruit (especially sour cherries, grapes, and strawberries), and vegetables (the superstars here are peppers and tomatoes).
Melatonin Supplements
Researchers and medical professionals typically recommend melatonin supplementation specifically for the treatment of insomnia and jet lag.
Even though your body synthesizes melatonin itself, production tends to slow with age. If your body is already struggling to produce enough, supplemental melatonin could be a helpful resource.
There are many types of melatonin supplements, including oral tablets, strips, lozenges, and capsules, liquids, rectal suppositories, gummies, and powders. Melatonin tablets are the most common form, offering ease of use and precise dosing. Some are even perforated, so you can easily break them in half.
Most types of melatonin supplements are consumed orally and have to make their way through the digestive system before taking effect. Even then, bioavailability may be as little as 10% in oral melatonin. But sublingual melatonin, which usually comes in sprays, dissolvable strips, or lozenges, provides faster absorption because it can bypass liver metabolism.
Supplements are also further distinguished between immediate-release and extended-release. Sublingual melatonin is usually immediate-release, while other forms of melatonin are usually extended-release. While immediate-release supplements are better absorbed and may work faster, they may not last as long in the body.
One small study that compared an extended-release tablet with an immediate-release sublingual spray found that the former better mimics the natural melatonin production cycle and may work better for insomnia. While the latter may help you fall asleep faster, it had a more dramatic drop in blood levels of melatonin after 90 minutes (meaning you could wake up faster, too).
However, very few studies directly compare the different types of melatonin and their effectiveness. Ultimately, the best form depends on individual needs and preferences. What helps one person feel contented and peaceful and sleep deeply could make another feel drowsy or even agitated. It may be wise to consult a health care provider to determine the most suitable option for your sleep health.
Are Melatonin Supplements Safe?
Melatonin is not officially FDA-approved for any indication because itʼs considered a dietary supplement. There are drugs that work with your bodyʼs melatonin receptors, such as ramelteon and tasimelteon, that are FDA-approved for treating insomnia.
Choosing supplements verified by United States Pharmacopeia (or USP, an independent nonprofit organization) can help assure their quality and proper dosing. All in all, melatonin is relatively nontoxic, although some mild side effects have been reported with higher doses and extended-release formulations.
Since melatonin is intended to make you sleepy, itʼs probably best not to take it before driving — or really any time you want to be awake. The most effective dosing schedule appears to be close to bedtime, to support a healthy circadian rhythm. Extended-release melatonin may increase the risk of grogginess or sleepiness in the morning, especially if you’re woken up prematurely. But contrary to popular belief, thereʼs no evidence that you can develop a tolerance to melatonin or that your brain will compensate by producing less of it.
Melatonin can interact with certain medications, however, so you might want to check with your health care team before taking melatonin, especially if you are taking any drugs. The most significant interaction with melatonin appears to be blood thinners. Also, people with epilepsy should only take melatonin under medical supervision due to conflicting reports of it either increasing or decreasing the frequency of seizures.
In some cases, melatonin supplements can also cause allergic reactions. Some melatonin-containing sleep aids may even include other relaxants such as GABA, ashwagandha, passion flower, or L-theanine. Make sure to read the ingredient label before using, especially if you have any allergies.
It’s also worth noting that most melatonin formulations are synthetic, but some are obtained from microorganisms, plants, algae, or even animals. To ensure your melatonin is animal-free, look for “vegan” on the label, or an identified source of melatonin.
How Much Should You Take?
Studies have shown that supplemental melatonin dosages range from 0.1–10 milligrams (mg). The standard starting dose is around 1–2 mg, and most experts recommend taking no more than 10 mg at a time.
In fact, thereʼs evidence that lower doses may be just as effective as higher ones, even though different people may respond best to different doses. In general, the best time to take melatonin appears to be between two hours and a half an hour before bedtime.
One of many USP-verified melatonin supplements you can take in tablet form is from Nature Made. At 3 mg per dose, itʼs a gentle formulation that may help you sleep better without unwanted side effects.
If you’re interested in trying an immediate-release sublingual melatonin, these peppermint-flavored lozenges from Source Naturals offer 2.5 mg per dose.
Plant-Based Recipes with Melatonin-Rich Foods
Explore the benefits of melatonin-rich foods with these three plant-based recipes designed to enhance both your health and your sleep quality. Each recipe features ingredients naturally high in melatonin, such as walnuts, tomatoes, and cherries, crafted into delicious, plant-powered meals. From savory Walnut and Lentil Stuffed Mushrooms to refreshing Tomato Bulgur Pilaf to sweet Toasted Pistachio and Cherry Overnight Oats, these healthy dishes are great additions to your diet, providing both exceptional flavor and a natural sleep aid.
1. Toasted Pistachio and Cherry Overnight Oats
Toasted Pistachio and Cherry Overnight Oats are perfect for a nourishing breakfast or a sleep-promoting evening snack. Cherries are a natural source of melatonin, which aids in improving sleep quality, while toasted pistachios add a satisfying crunch and a boost of healthy fats and protein. This combination helps enhance sleep but also provides essential nutrients for a great start to your day!
2. Walnut and Lentil Stuffed Mushrooms
Nearly every wholesome ingredient in these scrumptious and savory Walnut and Lentil Stuffed Mushrooms contributes to your health and well-being. Stuffed with a flavorful mix of walnuts, lentils, and aromatic spices such as oregano, cumin, and chili powder, these baby bella mushrooms are a gourmet treat. Walnuts are rich in beneficial fats and melatonin, which help regulate sleep cycles, making this dish an excellent choice for an evening dish to promote restful sleep. Plus, lentils boost the fiber and protein content, supporting digestive health and providing lasting fullness to help you sleep peacefully through the night.
3. Lebanese-Inspired Tomato Bulgur Pilaf
Savor the delicious and nutritious Lebanese-Inspired Tomato Bulgur Pilaf. This wholesome dish features fiber-rich bulgur wheat paired with fragrant onions and tomatoes, enhanced with a hint of tomato paste for added flavor depth. Slivered almonds contribute a delightful crunch and, together with the tomatoes, offer a natural source of melatonin to aid sleep regulation. Turmeric also provides a warm color and boasts anti-inflammatory benefits. Ideal as a hearty main course or a lively side dish, this pilaf promotes both healthy sleep and exceptional culinary enjoyment.
Embrace the Darkness Molecule
The natural hormone melatonin is a sleep aid and so much more! From bolstering the immune system to reducing the risk of certain diseases and conditions to acting as an adjunct therapy for cancer, melatonin offers a range of health benefits that can enhance your well-being. There are many natural ways to boost its production in your body, including through lifestyle and diet. For some people, supplements are also an option to try.
Tell us in the comments:
- Have you tried taking melatonin supplements? If so, in what format, and what did you experience?
Featured Image: iStock.com/Drs Producoes
