Caffeine on an Empty Stomach – Is It Safe for Your Cortisol?
Prefer to listen? I speak about all of this in episode 193 on Body Bites with Bec (which includes more personal insights and goes into a little more detail!
One of the most common questions I get from women in the Health with Bec community is:
“Is it okay to drink coffee first thing in the morning on an empty stomach?”
The short answer? YES – absolutely. But like most things when it comes to health and the body, there are many unique variables at play. So as always, the full picture is a little more nuanced.
Let’s dive into what’s actually happening with your cortisol levels, how caffeine fits in, and what to do if you suspect your cortisol might be running high.
First Up, What Is Cortisol?
Cortisol is a hormone produced by your adrenal glands. It’s often referred to as your “stress hormone”, but that’s only part of the story. Cortisol is often misunderstood because it's associated with chronic stress, anxiety, weight gain, and poor sleep when levels are elevated for too long.
But the truth is, cortisol is essential for survival and plays a key role in (1):
Regulating the sleep–wake cycle
Managing blood sugar
Reducing inflammation
Immune function
Supporting energy, focus, and alertness in the morning
Helping the body respond to physical and emotional stress
So, while cortisol is often viewed as a “bad” stress hormone, it’s actually essential for healthy energy, metabolism, and stress resilience – it only becomes problematic when chronically elevated, disrupting its natural rhythm.
Let’s dig into what this natural rhythm is…
Cortisol Follows a Natural Daily Rhythm
This is called your cortisol circadian rhythm (2). Here’s what it ideally looks like in a healthy pattern:
Morning: Cortisol peaks within 30–60 minutes of waking. This is a good response as high cortisol levels in the morning help you feel alert and energised.
Throughout the Day: Levels gradually decline.
Evening: Cortisol is at its lowest, allowing your body to relax and prepare for sleep.
This rhythm can be disrupted by things like chronic (i.e. long-term) stress, poor sleep, under-eating, over-exercising, certain medications – and yes, caffeine (3).
However, caffeine's impact on cortisol depends on how much you consume, the timing, and whether your body is already adapted to regular caffeine intake – meaning it doesn’t always cause a cortisol spike, especially in daily coffee drinkers.
Can Cortisol Be Tested – And Is It Worth It?
Yes, cortisol can be measured through blood, saliva, or urine tests. A standard blood test (usually done in the morning) can check your cortisol levels and may be ordered by your GP if there’s concern about adrenal issues.
However, unless you're being investigated for a specific condition like Cushing’s syndrome (high cortisol) or Addison’s disease (low cortisol), routine cortisol testing isn’t usually necessary or super helpful. That’s because cortisol naturally fluctuates throughout the day, and a single reading doesn’t always give the full picture.
However, I recommend seeing a functional medicine or integrative practitioner who offers saliva or DUTCH tests to track cortisol over a full day. This will allow you to see the full picture of your cortisol cycle and get a more precise indication of whether your levels are normal or not. These are usually private tests and not covered by Medicare.
Caffeine & Cortisol: The Real Story
There’s a lot of confusion about whether coffee spikes your cortisol, especially when consumed first thing in the morning.
Here’s what the research shows (4):
If You Drink Coffee Regularly…
Your body should be adapted to caffeine. This means your cortisol won’t spike dramatically when you drink it – even on an empty stomach.
Instead, caffeine gently prolongs your natural morning cortisol peak, helping you feel focused and energised for longer.
So yes – your morning coffee is safe, even on an empty stomach!
Want to Avoid That Afternoon Crash?
If you find yourself feeling foggy, tired, or reaching for a second coffee mid-afternoon, try this simple shift:
Delay your caffeine by 60–90 minutes after waking
This allows your body to ride its natural cortisol wave first, so when you do have caffeine, it gently extends that alertness without causing a sharp rise or fall.
Eating the right balance of nutrients at breakfast and lunch is also an important factor in helping to avoid low energy levels in the afternoon.
Caffeine Timing & Sleep
Even if you don’t feel “wired” from caffeine, it can still prolong cortisol’s presence in your bloodstream. Which can make it harder to wind down in the evening and can disrupt your sleep.
Which is why it’s recommended to avoid caffeine after 2–3 pm the latest (or earlier if you're sensitive). And if you struggle with sleep or anxiety, consider stopping by 12 pm.
What If You Suspect You Have High Cortisol Levels?
If you’re feeling wired but tired, struggling to fall or stay asleep, or are anxious, restless, or “on edge” in the evenings… these may be signs your cortisol is staying too high for too long.
Here’s what can help:
Delay caffeine by 60–90 minutes after waking
Avoid caffeine after 2 pm (or earlier for sensitive bodies)
Try to lower and optimise cortisol naturally
How To Optimise Your Cortisol Naturally If You Suspect It’s Out Of Whack
To support a healthy natural cortisol rhythm, try to build these healthy habits into your day:
Get morning sunlight exposure
Hydrate first thing in the morning
Movement or light exercise
Eat breakfast within 2 hours after waking – especially with protein
Slow, deep breathing at moments throughout the day (long exhales)
Caring for your gut microbiome by eating a plant-rich diet (like the meals inside my Health with Bec programs),
Calming wind-down routines before bed (magnesium, stretching, less screen time)
I share even more tips and strategies to help balance your cortisol levels in many of my Body Bites with Bec podcast episodes (links provided below!). In these episodes, I delve deeper into how high cortisol levels can impact your weight, cravings, and inflammation.
Don’t Forget: Coffee Has Its Benefits Too
It’s so easy to focus on one thing (in this case, caffeine’s impact on cortisol), feel unnecessary fear, and forget the bigger picture. Coffee isn’t a villain, and delivers health benefits too: Coffee helps to suppress your appetite, raises your metabolism, gives you more energy for your workouts, and supports longevity, not to mention it’s also extremely high in antioxidants. Research shows a moderate coffee intake is associated with a lower risk of type 2 diabetes, several cancers, and lower overall mortality (5). So, there’s no need to demonise coffee purely because the cortisol chat is circulating on social media!
Final Thoughts
At the end of the day, caffeine isn’t the enemy – it just comes down to timing, balance, and listening to your body.
☕ If you’re already a regular coffee drinker, enjoying your morning cup on an empty stomach is completely fine. For many women, it can even extend that natural morning energy boost without causing a spike in cortisol.
🌞 If you’re experiencing afternoon crashes, you can try to keep your energy levels more steady by delaying your first coffee by 60–90 minutes after waking, pairing it with nourishing meals, and cutting off caffeine by 2–3 pm (or earlier if you’re sensitive).
💚 And if you ever feel like your cortisol might be running high – think wired-but-tired, restless sleep, or evening anxiety – leaning into habits like morning light, hydration, gentle movement, balanced meals, and calming nighttime routines will help reset your rhythm.
Remember, coffee actually brings plenty of benefits too – from boosting metabolism to supporting longevity – so there’s no need to fear it. The key is simply being strategic so you can enjoy your daily brew while also supporting your hormones, sleep, and overall wellbeing.
Looking to Learn More About Optimising Cortisol?
I’ve shared loads of practical tips in my Body Bites with Bec podcast episodes and Health with Bec blog posts explaining how I personally manage stress and support healthy cortisol levels. Click the links below to explore the strategies I use in my own life:
Listen to these podcast episodes:
#48: The Link Between Stress and Weight and My Top 13 Tips to Get Yours Under Control!
#161: 6 essential things to remember if you want successful, SUSTAINABLE weight loss!
#179: Fix Your Gut, Fix Your Health with Dr. B, Award-Winning Gastroenterologist
#180: Chronic Stress & Burnouts Link To Tummy Fat & Halted Goals. It's Time To Step Up the Self Care
#184: The Sleep-Weight Loss Link (+ Game-Changing Sleep Tips!) with Sleep Expert, Olivia Arezzolo
#185: Life-Changing Boundaries That Cut My Stress and Transformed My Health!
Read these blogs:
References:
National Center for Biotechnology Information (2019). Physiology, Cortisol. StatPearls Publishing.
Jones, C., et al. (2021). Cortisol level dysregulation and its prevalence – Is it nature’s alarm clock?. Physiological Reports. 8(24), e14644.
Collomp, K., et al. Altered diurnal pattern of steroid hormones in relation to various behaviors, external factors and pathologies: A review. Physiology Behavior. 2016;164(Pt A):68-85.
Lovallo, W.R., et al. Caffeine stimulation of cortisol secretion across the waking hours in relation to caffeine intake levels. Psychosomatic Medicine. 2005;67(5):734-739.
Grosso, G., et al. (2017). Coffee, Caffeine, and Health Outcomes: An Umbrella Review. Annual Review of Nutrition. 37, 131–156.