Melatonin is generally known as the “sleep hormone,” but there are many other functions it plays in the body that in my opinion classify it as the most important hormone we produce!
Melatonin Production
When we are born we produce very little melatonin and rely on it primarily through breast milk. Once we develop our own circadian rhythms, this drastically changes and we reach peak levels up until about our 20s before levels start declining. This is one of the reasons elderly people often sleep less and/or have sleep issues!
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9571539/
We often associate melatonin with sleep because it gets released from the pineal gland when we receive the signal of darkness, and this helps to regulate our circadian rhythm. This is one of the main reasons why paying attention to your light environment at night by using circadian friendly lighting or Nighttime Sleep glasses is an essential health practice.
What most people don’t know is that melatonin from your pineal gland only accounts for about 5% of your body's melatonin production! The other 95% is produced intracellularly in your mitochondria throughout the body.
Melatonin Benefits
Melatonin is well known for its strong antioxidant capacity helping to modulate oxidative stress and reduce inflammation. Your cells (mitochondria in particular) are constantly producing reactive oxygen species through the process of energy production hence the need for a handy intracellular antioxidant such as melatonin to balance things out. Contrary to pineal melatonin, mitochondrial melatonin is produced from near infrared light (NIR) vs darkness. Conveniently, sunlight is composed of 42% NIR so simple sun exposure plays yet another crucial role in healthy biological function!
In addition to its antioxidant and anti-inflammatory benefits, melatonin plays a role in two important processes called apoptosis and autophagy. These are mechanisms to get rid of or recycle dead & damaged cells. This is one of the reasons that melatonin has also been studied as an effective anti-cancer compound as it can help to clear out dysfunctional cells! By now you can probably see that based on these mechanisms, melatonin can be very useful for various conditions.
Supplementing with Melatonin
Most people jump to the logical conclusion that they should take a melatonin supplement to harness all of these benefits, but it’s not quite that simple. In my opinion the primary strategy should be to increase your endogenous melatonin production and release with a “circadian lifestyle” including plenty of natural light exposure during the day and avoidance of blue light at night. You cannot replace these with any supplement! This is a comprehensive lifestyle based approach to melatonin optimization taken from this research article:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9571539/
If you are still struggling with sleep or have other health issues, melatonin is generally safe for adults (this is not as clear with children) but there is considerable variation in things like dosage, timing and even the form of melatonin (phytomelatonin vs synthetic) as people have very different responses. With a typical 3mg dose, some people swear by it as a sleep aid, some feel groggy in the morning and others report having frighteningly vivid dreams and swear to never take it again! It’s also important to note that the dosing strategy for something like cancer support can be entirely different and may involve taking doses of hundreds of milligrams during the day.
Summary
In my experience supplemental melatonin is best used to help fix a dysregulated circadian rhythm for something like shift work or jet lag. Otherwise as long as you are living in sync with the natural light and dark cycles of your environment, your body knows exactly what to do and will produce the right amount of this miracle molecule to keep you healthy and vibrant!