One of my Christmas presents was this book (above). Whilst there are many books about Melatonin that you can purchase online, I’m going to give you the main ‘Pro’ and ‘Con’ about this particular book.

PRO …

It’s written by Dr Russell Reiter, who is considered by many people as the world’s leading authority on melatonin - particularly, melatonin’s non-sleep and non-circadian capabilities. That is to say, that despite this being a popular book, Dr Reiter is a true scientist.

And to give you a sense of his standing, his H-index is 225.

That means he has published 225 scientific papers that have each been cited by other researchers at least 225 times.

For context, I haven’t even published 225 scientific papers. My H-index is a mere 64. Matthew Walker’s is 89. Andrew Huberman’s is 43.

But H-indices are influenced by how much you’ve published - and Russell Reiter is 85 years-old. Perhaps that’s got something to do with the fact that he takes supplemental melatonin every single day?

Something I’ve been doing for the past year too. But now for the …

CON …

This book was published in 1996.

In a recent podcast, Dr Reiter was asked whether he will write a new edition of the book - after all, the first edition was 30 years ago.

Dr Reiter answered - “It’s on the list” - but it’s never been high enough to get to the top of his list. That’s because he’s busily involved in so many research projects and papers about melatonin’s Swiss-army knife actions. His latest focus is on melatonin’s ability to address dementia.

But one of those Swiss Army Knife actions that I wish to highlight here is melatonin’s ability to influence your immune system.

Lately, researchers have been investigating melatonin’s ability to deal with the SARS-COV2 virus, and for many decades they have been interested in melatonin’s ability to fight cancer. Both of these topics involve the immune system.

So it’s worthwhile revisiting some Biology 101 in order to have a framework for understanding how melatonin boosts your immune system - starting with …

THE GENERALS - T-HELPER CELLS

Your immune system consists of a number of different cells, so it can be quite confusing to understand each single one.

And imagine that each type of immune cell was a soldier in an army, trying to perform their own role at the same time as other types of soldiers. It would be like those scenes in that show where contestants are spun around in a machine for a minute, and then have to race through an obstacle course. Initially, they’re running in random lines.

That’s why there’s a General for an army. And the T-Helper Cell is like your immune system’s General. They help to co-ordinate other immune cells.

That makes them sound very important - which they are.

But get this - T-Helper Cells are built with a specific docking station - a receptor - specifically designed to receive instructions from … drum roll …melatonin.

That means melatonin has a role at the very top of the immune system’s network.

Which begs the question - what is melatonin’s role in your immune system?

Dr Reiter’s book goes onto describe how melatonin flicks a switch on your T-Helper Cell, which in turn stimulates another type of immune cell - known as Interleukin-4 (IL-4), which in turn stimulates a host of other immune cells.

One of these immune cells has a really cool name -

THE SPEC OPS - NATURAL KILLER CELLS

These immune cells are designed to target your cells that are infected with a virus, as well as cancer cells.

These Natural Killer Cells are like the Special Operation Forces (Spec Ops) - outfitted with special gear to hunt down their target.

As Dr Reiter explains, viruses and cancer hijack your healthy cells and aim to multiply them - and they do this by tricking the majority of your immune system by making the hijacked cell looking healthy from the outside. Like a sort of camouflage.

But for the most part- Natural Killer Cells see through that bullshit. Like they have special night vision goggles that can see in the dark.

In his book, Dr Reiter describes an experiment where people took a mere 2 mg of melatonin each night for 2 months, their Natural Killer Cells increased by 240%.

And now for another type of immune cell that doesn’t have a cool name …

THE TANKS - PHAGOCYTES

There’s no good army metaphor for these shapeless fat blobs - so we’ll just post a picture of a tank for now. But these big blobs effectively consume unhealthy cells, absorbing them and killing them. They can be so hungry for unhealthy cells, that they can grow really fat and explode.

So whenever you see pus, know that this is a cemetery of a bunch of Phagocytes that ate themselves to death.

But with regards to melatonin, Dr Reiter cites a study where human cells went swimming in a solution of melatonin akin to the amount that is released by your pineal gland at night. This increased their ability to kill cancer cells by 73%.

THE RUNNER - GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR

GM-CSFs are like an army’s messenger, running off from the battle to garner reinforcements to join the battle.

These fellas run off to your bone marrow, inside your bones. Here, there resides what is theoretically your most immortal cell in your body - called a stem cell. When these stem hear from the messenger (GS-CSFs), then they begin creating a bunch of new immune cells to join in the fight.

Thus as Dr Reiter summarises - melatonin helps to create more stem cells in your body.

POST-1996?

I take a long time to read books and articles, because I inevitably go off on tangents and read other primary sources (ie, scientific articles) to verify what I’ve just read.

And given Dr Reiter’s book was published in 1996, it was a no-brainer to take a trek to my good friend - Google Scholar.

And the post-1996 research into melatonin promoting our immune system can be summarised in two words - honestly disappointing.

One would expect that after a 30-year-opportunity to perform research, that we would have learned more about melatonin’s ability to stimulate the immune system. A conclusion from a recent review states:

“Melatonin is able to increase NK and CD8+ cytotoxic T cells via triggering the release of TNF-α and IFNγ, while it reduces Tregs because of suppression of TGF-β. Melatonin has also been shown to suppress PD-1 expression, thus further amplifies the activity of CD8+ cytotoxic T cells.” - Mortezaee et al., 2019.

In other words, they concluded in 2019 that melatonin can enhance the activity of immune cells that help attack cancer, such as Natural Killer Cells and CD8+ cells - as well as reduce the influence of other cells that suppress the immune system.

However, this conclusion is primarily based on petri-dish studies of human cells and animal studies. Considering 30 years have passed, there’s barely any human studies. One study I was able to find was obscure, and showed that 20mg of melatonin was unable to prevent the inherent reduction of immune cells after chemotherapy …

This is interesting considering there are multiple studies that show 20mg of melatonin can reduce the side-effects of chemotherapy. It might mean the mechanism of reduced side-effects is not primarily due to the immune system.

If there was ever an important area of research, ripe for exploring, this is it. The question to be answered is: how much melatonin is needed to boost the immune system in the fight against cancer?

CONCLUSIONS

Cancer is such an important topic of research that any ‘sugar-coating’ should be avoided.

I do not see that we’re at a point in the research where we are seeing multiple human studies from independent research groups, that demonstrate the same finding.

If you look back at the title for this blog, you’ll see I’ve posed it as a question - because I feel that there is much more to be learned.

Learning about how melatonin can boost the immune system via cell and animal studies is excellent - but ultimately, people will ask the question “If I want to boost my immune system, how much melatonin should I take, and when?”. The answer to this question is what science needs to aim for.

But do not feel too disheartened, as I mentioned earlier, it may be that doses higher than 20mg per day may be needed - take for instance this ‘case study’ on a Facebook group:

And perhaps it helps to know how much the world’s melatonin expert takes per night. In a recent podcast, he says he’s currently taking 100mg.

Let’s just hope we see some decent human studies published in the coming years to support these experiences reported by some humans here and there.

• Prof MG

You can listen to Dr Russell Reiter in these below podcasts available on Spotify - plus you can find his book available on Amazon - and you will have access to dozens of his scientific papers on Google Scholar:

https://open.spotify.com/episode/19UVyu69FbNUm43J3t1g1M?si=931d110f19ff4cf4
https://open.spotify.com/episode/1jwEFF7rJpvT2vyvI8P5eo?si=f244e96f08fe475d

A NOTE TO WINK MEMBERS

The WINK Live Q&As for the first 3 months of 2025 have been organised.

In January, Dr Havard Kallestad will be our guest speaker, who will be describing his team’s research investigating the effects of a the building and testing of a Norwegian psychiatric ward purposely built with dynamic circadian lighting. But aside from different wavelengths influencing sleep and circadian timing, Dr Kallestad will speak to the ward’s lighting on aspects of psychiatric illness.

In February, we’ll learn about the importance of the amplitude of the circadian rhythm from Dr Renske Lok from Stanford University. Amplitude has often been ignored due to a focus on circadian timing, but I suspect Dr Lok will change our minds!

Finally, March will see the beginning of a new online course, delivered by yours truly. I’ll keep you somewhat in suspense, but please don’t hold your breath for the next two and half months because that’s just downright dangerous.

Keep an eye out for the Zoom links in the WINK Members FB group, as well as your emails.