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Melatonin: The Body’s Natural Sleep Guardian

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Last Updated on May 27, 2024 by Max


Melatonin, a vital hormone secreted in the shadowy hours of the night, whispers to our bodies that it’s time to rest, rejuvenate, and heal. But in our modern world, where artificial lights shimmer long after sunset and stress often disrupts our slumber, understanding melatonin’s role in sleep becomes crucial. Beyond its primary role, melatonin guards our cells as a potent antioxidant, shielding our DNA from the oxidative stress that can predict diseases like cancer. 

In this exploration of melatonin, we’ll journey through its nocturnal landscape, understanding its impact on our sleep-wake cycles, delving into its potential in cancer prevention, and uncovering the truths behind the supplements many individuals rely on. Join us as we step into the world of melatonin, our body’s natural beacon in the night, guiding us into the arms of Morpheus.

Melatonin’s Role in the Body

Melatonin is a hormone primarily produced by the pineal gland in the brain. Its primary function is to regulate our sleep-wake cycle, signaling our body when it’s time to sleep. But melatonin is more than just a sleep hormone. It’s also a potent antioxidant, which helps combat oxidative stress in the body. A study found that melatonin can reduce oxidative damage to DNA by up to 50% (Reiter, R. J., Tan, D. X., & Fuentes-Broto, L. (2010)). This is significant because oxidative damage to DNA can be a precursor to cancer development. Therefore, melatonin’s antioxidant properties play a role in cancer prevention.

The impact of melatonin suppression and its potential link to prostate cancer

Research has shown that melatonin can have protective effects against certain types of cancer. Specifically, evidence suggests that melatonin may be beneficial for prostate cancer. A study conducted on 928 Icelandic men found that those with higher overnight urinary melatonin levels had a statistically significant 75% reduced risk of advanced prostate cancer [source: Sigurdardottir, L. G., Markt, S. C., Rider, J. R., et al. (2015)]. Another study involving 2,425 men showed that those with above-average melatonin levels had a 31% reduced risk of prostate cancer (Bartsch, C., Bartsch, H., Flüchter, S. H., et al. (1992)).

One of the primary ways melatonin may influence prostate cancer is through its antioxidant properties. Oxidative stress, caused by an imbalance between free radicals and antioxidants in the body, can lead to DNA damage and contribute to cancer development. Melatonin is a potent antioxidant that neutralizes harmful free radicals and reduces oxidative stress. For instance, imagine a rusting piece of metal. The rusting is akin to oxidative stress, and melatonin is a protective layer that prevents the metal from rusting.

Moreover, melatonin has been shown to influence various cellular pathways crucial for cancer development and progression. For instance, melatonin can inhibit the activity of specific proteins and enzymes that promote cancer cell growth and spread. Think of it as a traffic cop, stopping the unruly behavior of particular cells that might otherwise go on to form tumors.

Another significant aspect is melatonin’s impact on the circadian rhythm. Our internal clock regulates numerous physiological processes, including hormone production, cell growth, and DNA repair. Disruptions to this rhythm, such as those caused by night shift work or exposure to artificial light at night, can increase the risk of various health issues, including cancer.

However, while these findings are promising, it’s essential to approach them with caution. More extensive clinical trials and studies are needed to establish the link between melatonin and reduced prostate cancer risk and determine the appropriate dosage and administration method for potential therapeutic applications.

Real-World Application: Melatonin and Radiation

Melatonin’s protective properties aren’t just limited to its antioxidant effects. Some studies have explored melatonin’s potential as a radioprotective agent. Radiation can cause DNA damage, leading to cancer. Research has shown that melatonin can protect against radiation-induced damage. In a study involving human blood lymphocytes, melatonin reduced radiation-induced chromosome damage by 55% (Vijayalaxmi, Reiter, R. J., Tan, D. X., et al. (2004)). Another study found that melatonin could protect against genetic damage in blood and bone marrow from whole-body radiation in mice.

Think of melatonin as the body’s natural “nighttime sentinel.” Just as a sentinel stands guard at night to protect a fortress, melatonin rises in our bloodstream, protecting against oxidative damage and potential threats like cancer. When the sun rises, the sentinel retreats and melatonin levels drop, signaling the body to wake up. But if we expose ourselves to artificial light at night, we confuse this sentinel, leading to decreased melatonin production. This disruption might make our fortress (our body) more vulnerable to threats like cancer.

Melatonin’s Production Throughout Life

From the moment we are born, our melatonin production undergoes various changes. At birth, melatonin levels are almost undetectable. As we grow, the production of melatonin increases, especially during childhood, when sleep is vital for growth and development. A young adult produces about 30 picograms (pg) of melatonin per milliliter (ml) of blood at night. However, this production can decrease with age. By age 70, the production can drop to around 14 pg/ml or even less (Zeitzer, J. M., Daniels, J. E., Duffy, J. F., et al. (1999)). This explains why some older adults experience disrupted sleep or insomnia.

Conditions for Melatonin Production

For optimal melatonin production, certain conditions are necessary. Darkness is a primary factor. The pineal gland starts increasing melatonin production in the late evening, peaking between 2:00 and 4:00 a.m., and then it gradually decreases as dawn approaches. Daytime levels of melatonin are minimal and almost undetectable. This is why it’s essential to have a dark environment for sleep, as even artificial indoor lighting can suppress melatonin production. Besides light exposure, other factors can influence melatonin levels. For instance, disrupted light-dark cycles, night work, and being overweight can modify melatonin production.

Dietary Influence on Melatonin

Certain foods can influence melatonin levels. For example, some edible plants contain melatonin and its precursor, tryptophan. Foods like tomatoes, olives, barley, rice, and walnuts have detectable amounts of melatonin. The bioavailability of plant-based melatonin has been demonstrated in both animals and humans. For instance, consuming melatonin-rich foods like vegetables or barley-based beer can increase blood melatonin levels.

Melatonin Suppressors

Several factors can suppress melatonin production. Light is the most influential environmental suppressor. Exposure to light during the evening, especially blue light from screens, can significantly reduce melatonin production and delay its onset. Caffeine is another factor. While coffee beans contain melatonin, the caffeine in coffee can reduce endogenous nocturnal melatonin levels. Alcohol, especially in excessive amounts, can also reduce melatonin levels in the blood.

In conclusion, melatonin is vital in regulating our sleep-wake cycle and has other potential health benefits. Various factors influence its production, including light exposure, age, and diet. Understanding these factors can help in optimizing melatonin levels and improving sleep quality.

Melatonin Dosage and Safety

Exogenous melatonin, taken as supplements, is commonly used to treat insomnia, other sleep problems, and even certain medical conditions like Alzheimer’s disease and autism spectrum disorder. It’s crucial to note that the optimal dosage of melatonin remains unknown.

A comprehensive review of 35 studies involving 2,356 subjects found that the most common side effect of melatonin was drowsiness, reported by 20% of subjects. However, most of these studies reported no significant side effects (Andersen, L. P., Gögenur, I., Rosenberg, J., et al. (2016)).

According to a narrative review titled “Chronic Administration of Melatonin: Physiological and Clinical Considerations,” published in Neurol Int in March 2023:

  • Melatonin usage has seen a significant rise in recent years. In the United States, melatonin is classified as a dietary supplement, making it accessible over the counter. Unlike prescription medications, no regulatory agency oversees its manufacturing or sale.
  •  The ability of melatonin to induce sleep is detectable, but the effect is modest for most individuals. The optimal dosage remains unknown, and the amounts used can vary widely.
  •  In terms of short-term adverse effects, melatonin is generally well-tolerated. Any side effects are usually minimal, resolve upon stopping the supplement, and don’t typically deter individuals from using it.
  •  Research on long-term melatonin administration has generally found no significant difference between exogenous melatonin and placebo regarding long-term adverse effects.

The conclusion from the review: Melatonin appears safe when taken at low to moderate dosages (around 5-6 mg daily or less). Long-term usage benefits certain patient groups, like those with autism spectrum disorder. However, the long-term effects of taking exogenous melatonin still warrant further investigation.

Body’s Natural Production of Melatonin

A common concern is whether long-term use of melatonin supplements can cause the body to produce less of its natural melatonin. The review mentioned that much research on long-term melatonin administration found no significant difference in long-term adverse effects between those taking melatonin and those taking a placebo.

Melatonin is available only by prescription in many countries, including the United Kingdom, the European Union, Japan, and Australia. This underscores the importance of using it under the guidance of a healthcare professional, especially when considering long-term use.

While melatonin appears safe for many individuals, especially at low to moderate dosages, its long-term effects remain an area of active research, especially on the body’s natural production. Always consult with a healthcare professional before starting or making any changes to melatonin supplementation.

Melatonin: Beyond the Pineal Gland

Recent research has expanded our understanding of melatonin production, revealing that this vital hormone is synthesized not only in the pineal gland but also in many other cells throughout the body, particularly within the mitochondria. Mitochondria, the energy powerhouses of our cells, have their own system of melatonin production. This subcellular melatonin, also known as extrapineal melatonin, constitutes a significant portion of the body’s total melatonin, far surpassing the amount produced by the pineal gland. Mitochondrial melatonin acts as a potent antioxidant, helping to neutralize free radicals and protect cells from oxidative damage​​.

One of the fascinating discoveries about mitochondrial melatonin is its production in response to red and near-infrared light. These wavelengths of light can penetrate deep into tissues, reaching the mitochondria. Studies have shown that red light therapy can stimulate the production of melatonin within the mitochondria, enhancing their antioxidant capacity and overall cellular health. This process is facilitated by the activation of enzymes like cytochrome C oxidase in the electron transport chain, which plays a critical role in melatonin synthesis​​.

The implications of mitochondrial melatonin production are vast. By supporting mitochondrial function and reducing oxidative stress, melatonin produced in the mitochondria helps maintain cellular health, which is crucial for preventing various diseases and promoting longevity. Furthermore, exposure to natural sources of red and near-infrared light, such as sunlight and certain types of artificial light therapy, can enhance this beneficial process​.

Incorporating more natural light exposure into daily routines, especially in the evening when melatonin levels naturally rise, can be beneficial. Red light therapy devices are also an effective way to boost mitochondrial melatonin production. These devices are becoming increasingly popular and are available in various forms, from handheld devices to full-body panels​.

Natural Ways to Support Melatonin Production

  1. Dance to Your Rhythm: Life’s a groove. Well, your sleep pattern should be, too! Hit the sheets and rise with the sun at the same beats daily. You’ll be conducting your symphony of sweet dreams before you know it.
  2. Tame the Blue Light Beast: As night falls, our digital devices love to throw rave parties, blasting our eyes with the blue light special. It’s a melatonin buzzkill! So, let’s dial down the techno-beat, slip on some blue-light-blocking glasses, or switch on those device filters. Your brain’s melatonin mixer will thank you for it.
  3. Feast Like a Sleep Wizard: Did you know that some of your favorite snacks are secret ingredients in the melatonin brew? Nuts, milk, and even tart cherries are like snooze potions in your pantry. Sprinkle them into your nightly nosh, and watch the magic happen.
  4. Serenade Your Stress Away: Stress is that one-party crasher we all know too well, and boy, it loves to keep melatonin at bay! Show stress the door with some chill vibes. Meditate, breathe deep, or unwind with some soul-soothing tunes. You’ve got this! For more insights on your personal stress levels and effective management strategies, consider taking our comprehensive Stress Level Assessment Quiz, designed to help you identify and mitigate stress factors impacting your health.
  5. Craft Your Den of Dreams: Transform your bedroom into a haven for hibernation. Imagine a cave of comfort draped in darkness, cool as the other side of the pillow and as serene as a whispering breeze. Blackout curtains, a white noise symphony, and perhaps a hint of lavender. Perfection.

By embracing these rituals, you’re boosting your melatonin and honoring your body’s natural rhythm, setting the stage for a night where dreams can thrive. So here’s to richer slumbers without reaching for the pill bottle!

Don’t keep your thoughts to yourself—join the conversation! Share your experiences, questions, and insights in the comments below. Together, we can make a difference in the lives of those affected by prostate issues. Let’s empower each other and create a supportive community! Comment now!


Melatonin is like a superhero for our body. It doesn’t just help us sleep; it fights off bad guys like cancer and protects us from other dangers. But sometimes, our body forgets to make enough of it, especially when we get older or don’t sleep well because of lights or screens. That’s why we need to help our body out!

How? We can ensure we sleep better by turning off our phones before bed, eating healthy snacks, and keeping our rooms dark and cozy for sleep. And guess what? Some foods are like secret weapons because they help our body make more melatonin!

But remember, if you’re thinking about taking extra melatonin like the pills you find in stores, it’s super important to talk to a doctor first. They’ll tell you if it’s a good idea and how much you should take. So, let’s take care of our body’s superhero, melatonin, and it will take care of us!


  • Zeitzer, J. M., Daniels, J. E., Duffy, J. F., et al. (1999). Do plasma melatonin concentrations decline with age? The American Journal of Medicine, 107(5), 432-436.
  • Reiter, R. J., Tan, D. X., & Fuentes-Broto, L. (2010). Melatonin: a multitasking molecule. Progress in Brain Research, 181, 127-151.
  • Sigurdardottir, L. G., Markt, S. C., Rider, J. R., et al. (2015). Urinary melatonin levels, sleep disruption, and risk of prostate cancer in elderly men. European Urology, 67(2), 191-194.
  • Bartsch, C., Bartsch, H., Flüchter, S. H., et al. (1992). Melatonin and 6-sulfatoxymelatonin circadian rhythms in serum and urine of primary prostate cancer patients: evidence for reduced pineal activity and relevance of urinary determinations. Clinical Chemistry, 38(5), 725-729.
  • Vijayalaxmi, Reiter, R. J., Tan, D. X., et al. (2004). Melatonin as a radioprotective agent: a review. International Journal of Radiation Oncology, Biology, Physics, 59(3), 639-653.
  • Andersen, L. P., Gögenur, I., Rosenberg, J., et al. (2016). The safety of melatonin in humans. Clinical Drug Investigation, 36(3), 169-175.
  • Melatonin, a Full Service Anticancer Agent: Inhibition of Initiation, Progression and Metastasis.
  • Evaluating the Association between Artificial Light-at-Night Exposure and Breast and Prostate Cancer Risk in Spain (MCC-Spain Study).
  • Zimmerman, S. and Reiter, R. 2019. Melatonin and the Optics of the Human Body. Melatonin Research. 2, 1 (Feb. 2019), 138-160.  

9 thoughts on “Melatonin: The Body’s Natural Sleep Guardian”

  1. It’s incredible to see how this hormone plays a crucial role not only in regulating our sleep but also in potentially preventing diseases like cancer. I also found the section on natural ways to support melatonin production quite helpful. It’s a great reminder to maintain a consistent sleep schedule and minimize exposure to blue light at night. Have you personally tried any of these sleep-enhancing strategies, and if so, did you notice a difference in your sleep quality? Thanks for sharing this informative post!

    1. Hi Stratos,
      Absolutely, Stratos! It’s fascinating. The more we understand melatonin, the more we realize it’s not just about sleep but our overall well-being. I’ve experimented with a few myself! Cutting down on blue light was a game-changer for me. Once I started reducing screen time in the evening and keeping gadgets away from the bedroom, I noticed I fell asleep faster and felt more rested in the morning. How can small changes significantly impact right?
      And you’re spot on about consistency โ€” it’s vital. Keeping a regular sleep schedule has helped me immensely, not just with sleep quality but also my energy levels during the day. It seems our bodies do thrive on routine.
      Have you given any of these strategies a go? I’d love to hear about your experiences or any other tips you might have come across. Thanks for your thoughtful comment, and here’s to sleep better and brighter days ahead!

      Best regards,

  2. The importance of sleep cannot be overstated.

    The closer a human being is to their natural state, the more healthy they tend to become. Naturally, when it’s nighttime, it’s supposed to be completely dark and we aren’t supposed to have artificial devices emitting loads of light, this definitely interferes with the quality of sleep we get. This may actually be the culprit behind many physical and emotional problems many people have in today’s world.

    Thank you for this informative article.

    1. Hey Yusuf,
      You’ve hit the nail on the head! It’s incredible how modern living, with all its gadgets and artificial lights, has drifted us away from our natural roots, especially regarding sleep. It’s like our bodies are expecting one thing (the natural cycle of day and night), but we’re giving them something totally different with all this screen time and city lights.
      I agree with you โ€” this shift might significantly affect some of the health issues many folks face today.
      Your insights are valuable. I’m all ears if you’ve tried any tricks to minimize light exposure or enhance your sleep quality! Sharing is caring, after all. Thanks for stopping by and contributing to this critical conversation!

      Best regards,

  3. Hey max,

    thx for the article ๐Ÿ™‚ it was very informative and rly interesting. I never thought of melatonin as a “nighttime sentinel” before, but it makes sense. I’ve been trying to improve my sleep, and this article gave me some good insights.

    I remember as a kid, I used to sleep so well, and now as I’ve gotten older, it’s been more challenging. Knowing that melatonin production can decrease with age explains a lot.

    I’ll definitely try to create a darker sleep environment, and maybe I’ll add some melatonin-rich foods to my diet. Thanks again for sharing this info! 😊

    1. Hey Matias,

      I’m really glad you found the article helpful! It’s interesting how certain aspects of our health, like sleep quality, change as we age, isn’t it? You’re spot on about melatonin being a game-changer for sleep.

      Creating a sleep-friendly environment can significantly impact your sleep quality, and it’s great to hear you’re taking active steps in that direction. Adding melatonin-rich foods is a fantastic move. Just remember, consistency is key, and it might take a little while to notice changes, but stick with it!

      If you ever have more insights or results from your new routine, feel free to share. It’s always great to hear real-life experiences. Thanks for your positive feedback, and here’s to better sleep ahead!

      Take care,

  4. I had no idea of the connection between Melatonin and sleep. nor did I know of the antioxidant properties it contains to protect against prostate and possibly other cancers. I am learning so much from your website and articles, I have to thank you! There are a number of ways we can protect ourselves from the onslaught of cancer and some of the tips you highlight are so helpful.

    I have a vested interest in learning and implementing all the advice as I have had 2 operations or removing skin cancer lesions and I do have an enlarged prostate (diagnosed over 20 years ago already). The steps I took back then have helped prevent more serious problems, of which I have no doubt.    

    Mostly I tend to control adverse health conditions by implementing common sense measures and these include diet/fitness/mindset regularly. It is through further study and learning that I add to the regimen practiced and sites such as yours are very useful. I will be paying more attention to melatonin from this point going forward. 

  5. Really cool piece on melatonin! It’s wild how it’s not just for sleep but also helps fight off stuff like cancer. Love the tips on boosting it naturally, like keeping rooms dark and eating certain foods. Makes you think twice about just popping a melatonin pill. Any specific sleep issues where these supplements are a game changer? 🌜💤🍒

    1. Hi bCloud09c,
      Thank you for your kind words! I’m glad you found the article on melatonin insightful. You’re right about the natural ways to boost melatonin being preferable in many cases. Regarding your question on specific sleep issues where melatonin supplements shine, they can be particularly effective for people with delayed sleep phase syndrome, where the body’s internal clock is out of sync with the desired sleep time. They’re also beneficial for individuals suffering from jet lag or those who work irregular shifts, as these situations disrupt the body’s natural production of melatonin. However, it’s always best to consult a healthcare professional before starting any supplement regimen, especially for chronic sleep issues.

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