If there’s one health trend we’d love to see retired on social media, it’s posts about cortisol.
If you regularly scroll through TikTok, Instagram or Facebook, it’s likely you’ll eventually encounter influencers pinching their ‘puffy’ cheeks to demonstrate their ‘cortisol face’ or blaming a ‘cortisol belly’ for their inability to lose weight.
The solution? A ‘cortisol detox’, apparently, which usually involves buying an expensive supplement.
But cortisol is a vital hormone that plays a key role in our everyday biology, not a toxin you need to purge from your body. Here, we untangle the truth from the nonsense, and explain the impact cortisol can have and how to manage it, with expert insight from Dr Angela Taylor, senior research fellow in metabolism studies at the University of Birmingham.
What is cortisol?
Cortisol acts primarily as a stress regulator, which is why it often gets called the ‘stress hormone’. But it also regulates your blood pressure, manages how your body uses carbohydrates and fats for energy and keeps inflammation in check.
It also helps to regulate your circadian rhythm (your sleep/wake cycle). Cortisol levels should reach their peak about half an hour after you wake up – providing a sort of natural caffeine effect needed to start your day. In the evening the levels then taper off, allowing melatonin to take over and lull you to sleep.
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Are ‘cortisol face’ and ‘cortisol belly’ actually a thing?
No, neither ‘cortisol face’ nor ‘cortisol belly’ are legitimate medical terms.
Dr Angela Taylor, who leads the Steroid Metabolome Analysis Core team at the University of Birmingham medical school, explains: ‘Cortisol is a steroid hormone essential for life, playing a critical role in processes such as immune function, stress responses and glucose metabolism.
‘Social media frequently claims that everyday stress or minor hormonal fluctuations can cause so-called ‘cortisol face.’ In reality, the rounded facial appearance known as ‘cortisol/moon face’ occurs only in conditions where there is sustained, pathological cortisol excess, which is very rare.’
In reality, facial puffiness or water retention is usually likely to be down to everyday lifestyle factors such as high sodium intake, poor sleep or alcohol consumption.
Similarly, while chronic cortisol elevation can increase appetite and encourage fat storage around the middle, it is rarely the lone culprit for weight gain. It is simply one factor in the complex interactions between your metabolism, diet and movement.
Cortisol myths vs reality
We asked Dr Taylor for her verdict on common cortisol myths:
Myth 1: you need expensive supplements to ‘balance’ your hormones
The cortisol detox industry is built on the idea that you can supplement your way out of stress. Influencers often push ‘adaptogens’ like ashwagandha, rhodiola, or ‘adrenal cocktails’ (typically a mix of orange juice, sea salt and cream of tartar) that are claimed to balance hormones and calm cortisol.
The reality As Dr Taylor explains: ‘Your body’s hormone system is highly complex, with different hormones needed at different times, varying by age, sex, and daily circumstances. Claims that supplements like ashwagandha can balance or reset hormones are not scientifically accurate.
‘Adaptogen is a pseudoscientific marketing term: unlike medicines, which are rigorously tested for safety and efficacy, dietary supplements are regulated as foods, meaning their effectiveness and safety are not guaranteed. Small studies may exist, but the evidence is limited and the research is often poorly designed.
‘At best, users may experience a placebo effect; at worst, supplements could interact with medications or cause harm. Good diet, exercise and lifestyle remain the best ways to support healthy cortisol levels.’
Myth 2: a single test can tell you if your cortisol levels are ‘wrong’
Many wellness brands now offer finger-prick home blood tests or saliva kits to check your hormone levels, promising to tell you if you are stressed or burnt out.
The reality ‘At-home finger-prick cortisol or testosterone kits can feel empowering, but a single snapshot can be highly misleading,’ explains Dr Taylor. ‘Hormones like cortisol follow a diurnal rhythm; levels are naturally higher in the morning and lower in the afternoon, so time, food, and other factors can drastically affect results.
‘Lab quality, reference ranges, and lack of clear interpretation by a medical professional mean results may be inaccurate or uninterpretable.
‘These kits rarely provide clinical guidance, so whatever your result – low, normal, or high – the advice is almost always just to consult your doctor. If you have concerns about your hormones, consulting your GP directly is safer, more reliable, and free!
‘Additionally, these kits are often used as a marketing hook, with companies marketing additional tests or supplements based on your results, creating unnecessary expense and potential risk.’
So a single high reading doesn’t necessarily mean anything bad; it might just mean you had a stressful Tuesday morning. Without a medical professional to interpret these results within the context of your overall health, these kits often (ironically) provide more anxiety than clarity.
Read more on the pros and cons in our guide to self-test kits.
Myth 3: high cortisol is the reason you can’t lose weight
The ‘stress belly’ narrative implies that if you just lowered your cortisol, any excess weight would melt off effortlessly.
The reality While it’s true that chronically high cortisol can increase cravings for high-sugar, high-fat foods, weight gain is usually a result of the combination of things that we do when stressed – sleep less, move less and eat more – rather than the hormone acting alone.
Treating cortisol as the sole villain oversimplifies the complex relationship between our metabolism, our environment and our habits.
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So, when is cortisol actually a problem?
While ‘cortisol face’ is a made-up term, chronic cortisol elevation, where your body remains in a ‘switched on’ state for weeks or months, is a genuine physiological issue.
If you are suffering from relentless psychological stress, your body is constantly flooded with cortisol, and at that point it stops being a helpful wake-up call, and starts becoming a drain on your system.
Common signs that your stress levels are physically impacting you include fragmented sleep, persistent fatigue, irritability, brain fog and digestive issues.
While lifestyle-induced stress is common, there are also rare instances where cortisol levels are genuinely a problem or indicate something more serious, such as with Addison’s disease or Cushing’s syndrome, but these are very rare.
Dr Taylor explains: ‘Cushing’s syndrome affects only around one to three people per million each year. To put this into perspective, in a city the size of London, this would equate to roughly 10-30 new cases per year.
‘The rise of the “cortisol face” on social media demonstrates how a rare medical symptom can be turned into an eye-catching visual scare, driving unnecessary worry, self-diagnosis, and, in some cases, real harm.’
If you’re concerned about the impact symptoms are having on your life, or you have new unexplained symptoms, it’s worth booking an appointment with your GP.
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How to manage cortisol, the evidence-based way
If you want to support your body’s natural cortisol rhythm, you don’t need a detox or a cabinet full of supplements. The most effective tools are lifestyle changes (though we appreciate these aren’t always easy to fit in!).
Managing high cortisol is more about creating an environment where your body doesn’t feel the need to be on constant high alert:
Pay attention to your caffeine intake
Caffeine doesn’t just wake you up: it prompts your adrenal glands to release extra cortisol. So if you drink it soon after waking – when your natural cortisol production is already at its peak – you are essentially layering stimulant on top of stimulant.
The fix Some experts suggest waiting 60-90 minutes after waking up to have your first coffee, the theory being that this lets your natural cortisol levels peak then begin their natural descent first, allowing the caffeine to work with your biology rather than overriding it.
However, other research suggests that while caffeine can temporarily increase your cortisol levels, the effect is much smaller in people who drink coffee daily. Either way, monitoring the effect that caffeine has on your perceived stress levels at different times of day may be beneficial.
Master your sleep hygiene
Sleep is the single most powerful regulator of cortisol. Even one night of poor sleep can cause cortisol levels to be significantly higher the following evening, creating a vicious cycle of being ‘too stressed to sleep’.
The fix It’s easy to say, if less easy to achieve, but aim for a consistent wake-up time. Exposure to natural sunlight within 30 minutes of waking also helps to regulate your circadian rhythm. This light signals your brain to reset its internal timer, ensuring that cortisol peaks when you need energy and drops off when you need to wind down for bed.
Choose the right exercise for your stress levels
While exercise is great for long-term stress management, high-intensity interval training (HIIT) causes a temporary spike in cortisol. If you are already in a period of intense work stress or burnout, pushing yourself through a punishing HIIT session can sometimes leave you feeling worse.
The fix If you’re feeling stressed already, swap the sprints for zone 2 exercise – that is, activities like brisk walking, gentle jogging, swimming or steady cycling where your heart rate is raised but you can still hold a conversation. This will still improve your cardiovascular health and lower your baseline stress without taxing your adrenal system.
Take ‘micro-breaks’ and focus on your breathing
You don’t need to do hours of meditation to get stress-relief benefits. Research shows that even a minute of focused deep breathing can stimulate the vagus nerve, which acts as a ‘brake’ on the fight-or-flight response.
The fix A study published in Frontiers in Psychology found that deep breathing significantly lowered salivary cortisol levels in healthy adults. Try the 4-7-8 technique: inhale for 4 seconds, hold for 7, and exhale slowly for 8. While there isn’t much scientific evidence on this, many people find, anecdotally, that it helps them relax and drift off to sleep.
