8 curiosities about melatonin you didn’t know

Javier Colomer 6 min. of reading To Sleep Well Leave a comment

Melatonin has become, lately, a super popular supplement thanks to its undeniable qualities to help you fall asleep. In a time when stress and daily worries negatively affect the rest of many people, this hormone isn’t a miracle cure, but it’s pretty close.

But beyond its many benefits both for sleeping and for many other great effects on your body, you’ve got to admit you probably don’t know much, much about this incredible hormone. Until today, because this post is here to share 8 cool facts you didn’t know about melatonin.

The first thing you want to know before diving in is that society is facing an epidemic of chronodisruption and sleep deprivation that is hardly different, in terms of harmful effects, from other 21st-century epidemics like obesity or sedentary lifestyle. A silent and gloomy epidemic that gradually wrecks health. The good news is that melatonin supplements are becoming a key piece to improve your rest. Let’s get started!

Is it a synthetic molecule or does your body produce it?

You can say, without fear of being wrong, that melatonin is way older than you, unless you’re a photosynthetic cyanobacterium! In fact, melatonin has been known to exist in these organisms for 2.5–3 billion years, and yes, you read that right, billion with a “b.” So, no doubt about it, this is a molecule almost as ancient for life as Earth itself, which explains its importance.

Where and how is Melatonin produced?

Melatonin is produced in the pineal gland, tiny and shaped like a pinecone, located right in the center of the brain. Its synthesis is pretty complex, so here’s a quick summary!

Tryptophan, an amino acid, through an enzymatic reaction of hydroxylation, turns into 5-OH-Tryptophan (5-Hydroxy-Tryptophan)
5OH-Tryptophan, via decarboxylation, becomes You recognized it, right? That neurotransmitter everyone talks about known as the “happiness hormone.” Well, serotonin is the precursor of melatonin
Serotonin, through acetylation by the enzyme Arylalkylamine N-Acetyltransferase, turns into N-Acetylserotonin
This last one, through methylation thanks to Acetyl-Serotonin-Methyltransferase, becomes the prized hormone – and that’s it, our hormone formed after this tight enzymatic process!

Does it appear in peripheral tissues?

Yes, it does, but its relevance is lower than in the CNS. In fact, melatonin is released in the cerebrospinal fluid (CSF) where its concentration is 100 times higher than in peripheral tissues and structures. However, it plays a metabolic modulatory role in peripheral structures as important as the liver or pancreas.

And what does it do in the CNS?

Well, a ton of things, but let’s talk about the most important one: circadian synchronization. Melatonin acts as a synchronizer of the master circadian regulator, also called the suprachiasmatic nucleus. Besides, it downregulates neuronal firing rate, acting as a neurodepressor, induces sleep for the same reason, and works as a powerful antioxidant with strong neuroprotective effects.

What’s its half-life?

Super short, between 20 and 30 minutes! This is why you should take it half an hour before going to bed, so it kicks in during that time and helps you fall asleep, letting the rest of the night be covered by your body’s own melatonin secretion.

Some compounds, like Circadin, are designed precisely to protect this hormone’s short life. It’s true that melatonin supplements don’t replace all the benefits of a good night’s sleep, but they give you a solid boost!

Is Melatonin produced outside the pineal gland?

It seems confirmed that yes. Certain retinal cells secrete melatonin and modulate their sensitivity to light and darkness. Similarly, it’s been shown that melatonin has an important effect on activated macrophages and lymphocytes, promoting their shift to Macrophage 2, increasing phagocytic activation, and triggering cytokines aimed at resolving inflammation.

In the digestive epithelium, melatonin secretion has been found from enterochromaffin cells that play a crucial role in regulating intestinal motility, immune response in the gut, ion transport in the lower digestive tract, and releasing peptides involved in energy balance, like peptide YY.

And anywhere else?

Recently, melatonin secretion was found in a super unexpected place: the mitochondria of mouse brain cells and mouse oocytes!

A one-of-a-kind discovery, since melatonin was thought to be synthesized only in the cell cytoplasm. Needless to say, we have no clue yet about melatonin’s role inside mitochondria, although studies suggest it protects mitochondrial DNA, being the most powerful antioxidant the human body can produce!

Can we say it’s an antioxidant?

Yes, but not just any antioxidant. We just said it. It’s the most powerful one known in biology! To give you an idea, its antioxidant power is 300 times greater than glutathione, another cell protector!

Now you know what you’re depriving your body of when you skip a good night’s sleep. It’s the high price you pay for night shifts (on top of everything), binge-watching series on your tablet, or partying with friends until you drop.

What do you think about these curiosities about melatonin? We hope they helped you get a little closer to the “sleep hormone,” that great ally when insomnia becomes your nightly partner and refuses to “end the relationship.”

More info to check out on this topic: