Melatonin & Cortisol. The Critical reset of our Circadian Clock. Sleep series Part 2

Cortisol vs melatonin
The dance between the hormone of darkness, Melatonin and the hormone of light, Cortisol.

These are the 2 hormones responsible for creating our circadian rythym, a 24hr cycle of light and darkness our internal seesaw.

If cortisol is up, melatonin is down and vice versa, what we are supposed to be doing is taking advantage of the right time that melatonin or cortisol is meant to be up, and trying to protect ourselves from what is called circadian mismatches created by signals that are telling us its the wrong time of day.

Cortisol: – the hormone of light – also known as the stress hormone, it’s not a bad guy – around the hours of 5 and 7 am is when it’s making its way up usually around sunrise, we are creatures who are tethered to the sun when it’s at its highest/peak at sunrise it signals us to wake up, it’s at its high for 30 minutes upon waking then slowly makes it way down as the sun moves across the sky, it activates our metabolic rate, allows us to absorb nutrients from the food we eat, gives us get up and go, without this we would not want to get out of bed its a very useful hormone and very much required, however when these levels are chronically high, meaning high at the wrong time of day and for extended periods of time, it does have detrimental effects on our body.

Cortisol at high levels suppresses the Immune system, most of us are triggered in an environment that keeps our cortisol high and so what we are doing is suppressing our immune system.

We want to avoid this, we want to be mindful of our cortisol levels and want to mitigate against having high levels of cortisol at the wrong time and high levels at the right time

Common Cortisol Mismatch No:1

Before the invention of electric light, we would have candles, oil lamps, and fires.

During that time we tended to rise when the sun rose, be quite active when the sun was in the sky, cortisol spiked then made its way down after sunset, cortisol levels were dropping and we would sit around fires and candles and spend time with our tribe, family, eat a meal around 8.30-9 then there wasn’t much else to do except either sleep and/or have sex, our melatonin levels around this time were on the way up, peek around midnight then slowly make there way down as cortisol would start to rise again, this is the circadian rhythm that we are programmed with and lived according to for 100’s of thousands of years.

Around the 1880 the first elctric light bulb was created – what this did was change our environmental signals.

There are 6 colors of natural light, purple, blue green red, yellow orange.

An old school bulb would have a full spectrum of colors they were as close to fire as you can get with an electric light bulb, these didn’t so much cause serious mismatches with our rhythms.

Then came along Fluorescent light bulbs; allot more energy efficient , but have a allot of blue spectrum of light in them

Then LED: very/most energy efficient but the trade off is that they are 99.9 blue light.

Why does this matter?

In the eye, we have a photoreceptor protein called melanopsin, the purpose of melanopsin is to scan the environment for a particular frequency range.

Blue light on a particular concentration exists only from the sun and so our biology needs to know that the sun is in the sky so that it can keep our cortisol levels up so we can keep going through the day, when there is no blue light in the atmosphere or very little from what we evolved with, fire, a different signal is sent, melanopsin receives a signal that there is very blue light so it must be night time, I need to have my cortisol levels come down so that melatonin can be secreted into the bloodstream.

The first mismatch, that we have created is the use of electric light in our homes, think about your living room, bedroom and very specifically your bathroom, you walk in it 9-11 pm, your in a winding down process, getting ready for bed, you turn on the light in the bathroom, and it tends to be the brightest room in the house, the signal comes on through melanopsin, Oh its daytime, ramp up /secrete cortisol level, suppress/ takedown melatonin levels

Then we go to bed we toss and turn and we wonder why is it that I am tired but I can’t fall asleep? We want to be mindful of environmental signals sent from our environment, received by the eyes that either suppress or secrete cortisol/melatonin.

Electric light is here to stay, so how do we mitigate this?


1) Use lamps with warmer, so light is eye or below eye level. Salt lamps are very calming on the nervous system and release off ions that clean the air, Moon lamps also have a remote control so you can alter the shades of light.

2) Red light bulbs – as close to fire as we can get, least effect on melanopsin, in the bathroom if possible as well.

3) Use a simple analogue clock at night, a common mismatch is using our phone as a clock – this needs to be avoided not only because of the EMF issue which I will discuss in the next Article but when you look at your phone to check the time at night the blue light from phone hits the retina, game over for continued sleep, cortisol starts to spike and we start to wake up.

Addressing the Elephant in the room.

Our devices our screens of all kinds are heavy in the blue light spectrum this is because these devices need to be energy efficient, very specifically the phone.

If you could set yourself a little Kerfuw, no screens 2/3hrs before bed, and instead use that time to connect with family, read a book then, of course, this is the best, but if you are saying you just can’t do that, because I’m just addicted to my phone or watching TV is my wind-down routine, etc, then;

Here is how we mitigate;

Blue blocker glasses, in the evening after sunset, you can get yellow, orange, and red, the deeper the red the more effective.

They are so easily available now, and can also be got in prescription lenses for any of these tints also.

One step further; use a red filter on your screen, there are applications of software available online and many of them are free, we can install them to shift the frequency of blue into red.

These are the two I Highly recommend, F.lux which is free and Iris tech which has a small annual cost but it well worth it as it has biohacker mode, so if you need to programme or write into the evening, it does this thing where it removes all the white and blue and makes your background red.

I have added the links for both of these below;

Blue light vs red light experiment:

2 groups were used;

The 1st grp were told to read for 1 hour on an IPad before bed

The 2nd grp were told to read a paperback book for 1 hour before bed

The ipad group showed, Melatonin release was delayed for 3hrs and the total deep sleep time was 50% less than than the grp who were told to read a book.

This is significant!

Psycho Active stimulants; Sorry Spoiler Alert coming up

This is my least favourite part of this blog but it’s a very important piece;

Coffee, Green tea/matcha Tea have high levels of caffeine in them, a single shot expresso taken at 8 am depending on the quality of the coffee still has a half-life of 8 hrs so at only 4 pm 50% has made its way through and out and you still have 50% left in the bloodstream, which means at midnight you still have 25 mg coffee still in your system, more caffeine = less deep sleep and more dream sleep.

Recommend decaffeinated – just as good – and your not robbed of the experience of coffee.

Alcohol – better at lunchtime – as it needs 3 hrs for the liver to detox the aldehydes – I’m not against drinking it really is just about timing, most of us can say we experience a poor night sleep after drinking into the evening, this is mostly because the Liver is working extra hard and this stops us from dropping into any kind of deep sleep.


How do we Reset our Circadian Rhythm?

We are programmed to make melatonin first thing in the morning when natural light hits the retina, when this happens a signal is sent to the pituitary gland to release a cascade of metabolic hormones one of which is called serotonin, a happy hormone, its a precursor for melatonin, a big hit of this equals big hit of melatonin equalling more deep sleep time naturally

Remember that our focus here is to always set ourselves up for melatonin in the evening.

So what we would benefit from is getting light through the eyes first thing in the morning BEFORE checking our devices, natural before artificial light, it is very important to change this habit.

This is natural light not through glass not even glasses – exposing eyes to light naturally, releases lots of serotonin and dopamine, and releases high levels of cortisol to energise us.

This way of living has become lost for us and this is one of the reasons why we are seeing a lot more cases of depression, and lower melatonin levels, a mismatch in our circadian rhythms

What I am suggesting we do at least a few days a week is to go outside as soon as we get up in the morning even if for just a couple of minutes, maybe take a cup of coffee or tea with you and expose your eyes and as much of your skin to the light. don’t stare in sun, peripheral vision is best, light is designed to constantly enter the eyes through Peripheral vision, and if it’s cloudy, no worries it still works, you might be better to just add a few more minutes to it though.

How does this practice of exposing the eyes first thing in the morning set the circadian clock?

As I mentioned before Sunlight is made up of 6 colors, but in the morning there are only 5, it has no purple in it otherwise known as Ultraviolet light. In the morning a signal is sent through the retinas to something called The suprachiasmatic nucleus, which is also known as the circadian clock or master clock, it is a tiny region of the brain in the hypothalamus, situated directly above the optic chiasm. It is responsible for controlling circadian rhythms. The neuronal and hormonal activities it generates regulate many different body functions in a 24-hour cycle.

So exposing the eyes to natural light specifically in the morning tells our brain that it is morning time which means it can release a cascade of serotonin which is the precursor to Melatonin, later in the day around midday the sun now has ultraviolet added to it, it is higher, warmer, and brighter signaling to the brain that it’s now afternoon which also, by the way, is the only time that we can synthesize Vitamin D naturally.

By Sunset time – purple has gone, and the ratio of red is higher, which then signals to the brain that evening is here, which means? Yes, Melatonin time!.

How will I know when my Circadian clock has been reset?

Once the circadian clock is set we will know because we will naturally wake up around sunrise at the top of one of our cycles and will naturally start to feel sleepy around 9 – 9.30 /10 this is how we are designed our biology craves this. When the clock is set our biology functions according to how we have evolved, being consistent with this we will naturally fall asleep at the above times, have good quality sleep, Melatonin will be released when meant to and Cortisol will spike when meant to.

I do hope you have found this article useful and that it has helped to bring more awareness of your environment and inspired you to make some fundamental changes that will align your body back into finding its own natural rhythm again.

If you missed sleep series part one here is the link for that and also on my site you can sign up to receive my Free bedtime sleep hypnosis.

In service to helping you find your way back to delicious restorative sleep and more importantly you believing again that it is possible.

With love