Cortisol Throughout the Day: From Waking to Sleep

We have written a fair amount about cortisol, its intended purpose in your body, how modern life can be a little unfriendly to the intended use of cortisol, and how this has led to it being painted a little bit as a pantomime villain. You can read more about the basics in our article: What Is Cortisol?

In this article, we are going to look at something a little different: what cortisol actually does throughout the day. Higher cortisol isn't automatically bad, lower cortisol isn't automatically good, and your cortisol levels aren't supposed to remain the same from morning to night. Join us as we discover Cortisol throughout the day!

In fact, changing cortisol levels are part of a normal, healthy daily rhythm.

Upon Waking

Before you even open your eyes, your internal biological clock has already gone to work.

During the later stages of sleep, cortisol levels begin rising as your body moves towards its normal waking period. In other words, your morning cortisol doesn't suddenly appear because the alarm went off. Your body has already started preparing for the transition from sleep to wakefulness.

This is part of cortisol's normal circadian rhythm: the roughly 24-hour biological pattern that influences everything from sleep and alertness to hormone production.

The First 30–45 Minutes — The Cortisol Awakening Response

You open your eyes. The alarm is buzzing. You might imagine your body gently coaxing you into the day, but behind the scenes there is quite a lot going on.

Cortisol typically continues rising during the first 30–45 minutes after waking. This pattern is known as the Cortisol Awakening Response, or CAR for short.

Think of it a little like your body's internal double-shot of espresso.

The exact size of this increase varies considerably between people and even between different days in the same person. Researchers are also still investigating exactly how much of the increase is caused by waking itself and how much reflects the circadian rise that was already underway before you opened your eyes.

Either way, the important point is that higher cortisol in the morning is normal. Your body isn't necessarily stressed or malfunctioning. It is preparing you for the active part of your day.

Morning: The High Point (and the Great Coffee Debate)

Morning is generally the high point of your daily cortisol rhythm. Rather than being something we need to immediately suppress, cortisol is involved in several useful processes that help us get going.

These include:

• Energy availability: Cortisol helps regulate glucose metabolism, ensuring energy is available when your body needs it.
• Blood pressure regulation: Cortisol contributes to normal cardiovascular function and helps maintain blood pressure.
• Immune regulation: Cortisol also helps regulate inflammation and immune activity.

In other words, cortisol isn't ruining your morning. It is one of the reasons you can have one.

The Coffee Clash: Are You Drinking It All Wrong?

Now we arrive at one of the internet's favourite cortisol claims:

"Drinking coffee first thing in the morning ruins your cortisol levels!"

As is often the case with internet health advice, there is a little bit of genuine science hiding underneath a much larger blanket of exaggeration.

Caffeine can temporarily increase cortisol. Morning cortisol is also naturally relatively high. This has led to the popular idea that drinking coffee shortly after waking is somehow "stacking" caffeine on top of your natural cortisol surge and should therefore be avoided.

The problem is that this doesn't automatically mean drinking coffee in the morning is harmful or that everybody needs to wait a precise number of minutes before touching the kettle. Regular caffeine users can also develop some tolerance to caffeine's effects on cortisol.

So if you enjoy a coffee after waking, you don't need to start setting a stopwatch because somebody on social media told you your adrenal glands require exactly 90 minutes of peace.

Late Morning to Afternoon: The Gradual Decline (and the Truth About the Slump)

By late morning, the early-morning hormone party is winding down. Your overall cortisol level begins its gradual journey downwards.

This decline is completely normal.

It doesn't mean cortisol disappears, and it certainly doesn't mean your body has suddenly run out of the stuff. Cortisol continues performing important jobs throughout the day, and temporary increases can occur in response to things such as exercise, meals, caffeine and stressful situations.

The Afternoon Slump: Is It Actually Low Cortisol?

Then 2:00 or 3:00 PM arrives.

Your eyes get heavy. Productivity begins negotiating its surrender. The couch suddenly looks like the finest piece of furniture ever created.

It can be tempting to blame falling cortisol:

"Aha! My cortisol must be dangerously low!"

But feeling tired during the afternoon doesn't tell you that you have a cortisol problem.

Alertness is controlled by several interacting systems. Your circadian rhythm itself can produce an afternoon dip in alertness, while adenosine, a chemical that accumulates while you are awake, contributes to the increasing sleep pressure you experience as the day continues. Meals can also influence how alert or sleepy you feel.

So while cortisol is generally declining during the afternoon, the traditional afternoon slump is considerably more complicated than "cortisol went down, therefore I need a nap."

Although, admittedly, you may still want the nap.

Evening: Approaching the Daily Low

As evening arrives, cortisol continues moving towards the lower part of its 24-hour rhythm.

This evening decline is a normal feature of your circadian physiology—your body's internal clock gradually moving away from the active part of the day and towards biological night.

At around the same general period, melatonin begins rising as biological night approaches.

You will sometimes see cortisol and melatonin described as a simple see-saw: cortisol goes down, therefore melatonin goes up. The reality is a little more complicated. Falling cortisol doesn't simply flick a switch and turn melatonin on. Both hormones are influenced by the body's wider circadian system.

The important bit for everyday life is much simpler: high morning cortisol and lower evening cortisol are normal parts of the rhythm.

During Sleep: Low, Then Rising Again

During the early part of the night, cortisol remains around the lower part of its daily rhythm.

But it doesn't disappear.

Your body doesn't shut the adrenal glands down for the night, stick a little CLOSED sign on them, and wait for the alarm clock.

Cortisol continues to be released in pulses while you sleep. As the night progresses and your body begins approaching the next waking period, the overall cortisol pattern starts climbing again.

By the time you wake up, the whole cycle is ready to begin again.

Your Cortisol Isn't Actually Following a Smooth Curve

If you Google "daily cortisol curve", you will find a thousand similar infographics.

They generally show a beautifully smooth ski slope: cortisol starts high in the morning and glides gracefully down towards evening.

That isn't exactly wrong.

But it only tells part of the story.

Zooming In: The Secret Rollercoaster

If you could zoom in on cortisol throughout a real person's day, the smooth line would start looking considerably more chaotic.

Instead of steadily trickling into your bloodstream, cortisol is released in bursts known as ultradian pulses.

So while there is an overall circadian pattern taking you from generally higher morning levels towards lower evening levels, there are peaks and valleys happening throughout that journey.

Think of it this way:

The overall journey might be downhill like a ski slope, but you're riding a rollercoaster down it.

That distinction is important because a single temporary increase in cortisol doesn't necessarily mean your entire cortisol rhythm has gone wrong.

What Can Change Your Cortisol Rhythm?

This is where discussions about cortisol can get confusing.

There is an important difference between a temporary cortisol response and disruption to your broader circadian rhythm.

Temporary Increases

Exercise, caffeine, meals and acute psychological stress can all influence cortisol.

Nearly getting sideswiped in traffic, doing a difficult workout or dealing with a stressful situation at work can produce temporary changes in your stress-response system.

That doesn't automatically mean something has gone wrong.

Cortisol is partly there to help your body respond to changing demands.

Circadian Disruption

Something different can happen when the timing of your actual biological day becomes disrupted.

Sleep loss, irregular sleep schedules, shift work, travelling across time zones and exposure to light at unusual times can interfere with normal circadian rhythms.

This distinction matters.

A temporary cortisol increase can simply be your body responding to what is happening right now.

Circadian disruption affects the clock helping determine when things should happen in the first place.

What Does This Mean for Your Day?

Understanding cortisol is useful because it allows us to stop treating every increase as something that needs fixing.

Morning: Your body is naturally moving towards alertness. Higher cortisol at this time isn't automatically a problem—it is part of your normal biological preparation for the day.

Daytime: Temporary cortisol increases are normal responses to physical and psychological demands. Exercise, food, caffeine and stressful situations can all influence cortisol without necessarily disrupting your overall rhythm.

Evening: The normal trajectory is towards lower cortisol as your body approaches biological night. A regular sleep schedule and an environment that helps you wind down can support the wider circadian processes taking place during this period.

Night: Cortisol remains relatively low during the earlier part of the night before the overall rhythm begins climbing again towards morning. Sleep and your circadian system interact with cortisol rather than simply switching it off.

The Central Takeaway: It's Not About Keeping Cortisol Low!

If there is one thing worth taking away from all of this, it is this:

Managing cortisol isn't about keeping it as low as possible.

The wellness world has a habit of reducing the entire subject to:

LOW CORTISOL = GOOD

But cortisol isn't some toxic chemical your body accidentally produces and needs to detox.

We need cortisol.

Your body is supposed to produce different amounts at different times. Higher levels can be perfectly normal at one point in the day while lower levels are appropriate at another.

The important thing isn't chasing the lowest cortisol number possible. It is the normal regulation and timing of the system.

And that gives McCuddles a much more responsible place in the conversation.

We aren't going to tell you that a plush toy is a magical medical device that "reduces cortisol", fixes your hormones or cures stress. McCuddles is designed to be a comforting part of the routines people use when transitioning from a busy day towards rest.

Maybe that's reading for half an hour. Maybe it's dimming the lights, putting away your phone and getting comfortable. Maybe it's simply having something soft and reassuring to cuddle while the day's nonsense finally comes to an end.

Your body can handle the hormones. McCuddles is just here for the cuddle.