How to Reduce Cortisol: What the Evidence Supports

By Adrian Stone, BHSc (Nutritional Medicine), BHSc (Naturopathy), Living Holistic Health — the first part of our Stuck in Fight or Flight series: how to reduce cortisol, starting with what the evidence actually supports rather than what is being sold.

On this page

1. 01How We Weigh the Evidence
2. 02What Does Cortisol Actually Do?
3. 03What Are the Signs of High Cortisol?
4. 04What Causes High Cortisol?
5. 05How to Reduce Cortisol Naturally: What the Evidence Supports
6. 06Can Supplements Reduce Cortisol?
7. 07Should You Get a Cortisol Test?
8. 08How Long Does It Take to Reduce Cortisol?
9. 09When Should You See Your GP?
10. 10The Bottom Line on How to Reduce Cortisol
11. 11Frequently Asked Questions
12. 12References

Cortisol is having a moment online. Cortisol face, cortisol belly, cortisol cocktails: most of it is selling something. However, cortisol is not the villain. The real problem is a stress system that never switches off.

In clinic, I call this sympathetic nervous system dominance. It is one of four root drivers I see behind almost every case, whatever the presenting complaint. I often tell patients: if the body is stressed, it cannot properly heal. That is why this series, Stuck in Fight or Flight, starts here, with how to reduce cortisol.

How We Weigh the Evidence

Naturopathy is evidence based. It just depends which version of ‘evidence’ you are prepared to look at. So, throughout this series, I show two kinds side by side. Traditional evidence is what a system such as Ayurveda or yoga has documented over centuries. Trial evidence is what modern human studies measure.

Importantly, I label each one and never blend them. They answer different questions. Tradition tells us what people have used and why researchers went looking. Trials tell us what can be measured today. Neither layer, on its own, tells you whether something suits you or what its risks are.

What Does Cortisol Actually Do?

Cortisol is your main stress hormone, made by the adrenal glands under direction from the brain’s HPA axis. It raises blood sugar, sharpens alertness, dampens inflammation and sets your daily rhythm. It peaks about 30 minutes after waking and falls to its lowest around midnight. Problems start when it stays high when it should be falling.

In fact, short bursts of cortisol are healthy. They get you out of bed, through a deadline and away from danger. However, the trouble is repetition without recovery. The neuroscientist Bruce McEwen called the cost of that wear and tear ‘allostatic load’.¹ Our post on cortisol belly goes deeper into that idea.

What Are the Signs of High Cortisol?

Common high cortisol symptoms include feeling ‘wired but tired’, trouble falling asleep or waking at 2 to 4 am, and cravings for sugar or salt. Others are more weight around the middle, getting sick more often, low mood or irritability, and slow recovery from exercise. These overlap with many conditions, so symptoms alone can’t confirm high cortisol.

Physical Signs of High Cortisol

In general, the physical pattern tends to show up as tiredness that sleep doesn’t fix, headaches, tight shoulders and a racing heart at odd times. Some people notice more colds, slower wound healing or digestion that changes with stress. Similarly, others gain weight around the middle even though their eating hasn’t changed.

Mood, Sleep and Energy Signs

In particular, the classic picture is an energy curve upside down. You drag yourself through the morning, then feel switched on at 10 pm. Indeed, many people describe a short fuse, a busy mind at bedtime or waking in the small hours with their thoughts already racing.

Red Flags That Need Your GP

Notably, a small number of people have a medical cause of high cortisol, such as Cushing’s syndrome. Therefore, see your GP if you notice a rounder, fuller face, wide purple stretch marks, easy bruising, weak thigh or upper-arm muscles, or blood pressure that won’t settle. Your GP can arrange the specific tests.²

What Causes High Cortisol?

Most high cortisol in everyday life comes from chronic stress, short or broken sleep, too much hard exercise without recovery, heavy caffeine or alcohol, and blood sugar swings. Less often it’s medical: corticosteroid medicines or, rarely, Cushing’s syndrome. Working out which applies is the first step in learning how to reduce cortisol.

Generally, it is several of these at once. For instance, poor sleep makes the coffee feel necessary, the coffee makes the afternoon crash worse, and the crash drives the sugar. Each one nudges the stress system a little higher.

Is ‘Adrenal Fatigue’ the Same Thing?

No. A systematic review of 58 studies found no consistent evidence that ‘adrenal fatigue’ exists as a medical condition.³ Still, that doesn’t mean the symptoms aren’t real. Instead, the more useful idea is HPA-axis dysregulation: a stress response that is out of rhythm rather than worn out. The cortisol belly post covers the adrenal fatigue myth in more depth.

How to Reduce Cortisol Naturally: What the Evidence Supports

The best-supported ways to reduce cortisol are protecting sleep, a daily relaxation or mindfulness practice, regular time outdoors, moderate rather than punishing exercise, and cutting back on caffeine and alcohol. None works overnight. Together they lower the load on the stress system, which matters more than any single cortisol number.

Sleep: The First Lever to Reduce Cortisol

To begin with, sleep is where I start with almost everyone. In a classic study, one night of partial sleep loss raised cortisol the next evening by 37%, and a whole night without sleep raised it by 45%. The usual evening fall in cortisol also came later.⁴

Specifically, that means a regular wake time, a dim and screen-free last hour, and a cool, dark room. If hot flushes or 3 am waking are part of the picture, our post on perimenopause fatigue looks at sleep in midlife.

Breathing and Meditation to Reduce Cortisol

For example, a 2023 meta-analysis of 58 randomised trials, with 3,508 people, found that stress-management programs lowered cortisol.⁵ The pooled effect was small to medium. Mindfulness, meditation and relaxation did best. Talking therapies and other mind-body programs had smaller effects that were not statistically clear.

Similarly, in a small Chinese trial, 40 adults practised slow belly breathing for eight weeks. Compared with controls, their cortisol in saliva fell.⁶

However, here is the honest counterweight. A 2026 RMIT University review of 132 trials, with more than 23,000 employees, found meditation reliably eased perceived stress and anxiety and improved sleep. Yet it did not significantly change cortisol.⁷ I don’t see that as a failure. Feeling calmer is the outcome that matters; cortisol is one imperfect marker of it.

Time Outdoors to Reduce Cortisol

Time in nature is also one of the cheapest tools there is. In an eight-week study of 36 city dwellers, a ‘nature pill’ of 20 to 30 minutes lowered salivary cortisol by about 21% an hour, beyond its normal daily fall.⁸ The benefit per minute peaked in that 20 to 30 minute window, so you don’t need a whole day in the bush.

Old Practices, Modern Evidence

Moreover, two of the tools above have roots in much older practices. Here are the two layers of evidence for each, kept separate.

Traditional use

In the yoga tradition, breath regulation, called pranayama, is an essential part of practice. Ancient yoga texts put it this way: ‘As the breath moves, so does the mind.’⁹ Slowing and pacing the breath is one of its core techniques.

What the trials show

A Melbourne-led meta-analysis pooled 42 randomised trials of practices that included yoga postures.¹⁰ Compared with active control groups, they were linked with lower evening and waking cortisol, a lower resting heart rate and lower blood pressure. Still, the programs varied a great deal.

Traditional use

Shinrin-yoku, or ‘forest bathing’, is a Japanese practice of immersing yourself in nature by mindfully using all five senses. Notably, it is younger than it sounds. It took shape in Japan in the 1980s as part of preventive health care.¹¹

What the trials show

A meta-analysis of 13 studies, with 1,786 people, found forest therapy lowered salivary cortisol compared with city settings, and sessions of 20 minutes or more did better.¹² Admittedly, the results varied widely between studies, so some people may see little change.

Exercise: The Right Intensity to Reduce Cortisol

Exercise is a stressor too, so intensity decides which way cortisol goes. In one laboratory study, 30 minutes at an easy 40% of fitness capacity lowered cortisol once fluid shifts were accounted for. At 60% it rose by about 40%, and at 80% by about 83%.¹³

Of course, hard training is fine. Rather, the problem is hard training with no recovery. Instead, walk most days, and keep the intense sessions purposeful and spaced out.

Caffeine, Alcohol and Blood Sugar

In particular, across two groups of 128 and 148 young adults, regular caffeine users had bigger cortisol responses to a stress test.¹⁴ Therefore, keep coffee before midday, and notice whether it is propping you up. Meanwhile, alcohol fragments sleep in the second half of the night. Regular meals with protein steady blood sugar, which avoids the cortisol spikes that come with skipped meals.

Admittedly, none of this is glamorous, and positive change means sacrifice. Still, these are the levers that move the whole system, not just one number.

Can Supplements Reduce Cortisol?

A few supplements have some human evidence for lowering cortisol. Omega-3 fish oil and ashwagandha have the most, but effects are modest and none replaces sleep and stress management. Magnesium supports the stress response, but direct cortisol evidence is thin. Discuss any supplement with your practitioner, especially if you take medication.

Omega-3 Fats and Cortisol

In fact, in a four-month trial of 138 midlife adults, the higher of two omega-3 doses produced 19% lower cortisol across a laboratory stress test, compared with placebo.¹⁵ Oily fish such as salmon, sardines and mackerel are also the food source.

Magnesium and the Stress Response

Meanwhile, stress increases the magnesium lost in urine, and low magnesium appears to make the stress response more reactive. Researchers call it a ‘vicious circle’.¹⁶ However, most of that evidence is mechanistic or observational rather than from trials, and several of the review’s authors work for a supplement manufacturer. Part 2 of this series looks at magnesium in detail, and our magnesium deficiency post covers the basics.

Ashwagandha: Two Layers of Evidence

Traditional use

Ashwagandha has been used in Ayurvedic medicine for more than 3,000 years. Classical texts such as the Charaka Samhita and Sushruta Samhita describe it as balya, strength-giving, and Ayurveda counts it among the rasayana, or rejuvenative, herbs.¹⁷

What the trials show

A 2025 meta-analysis of seven trials found cortisol fell with ashwagandha, by about 1.16 µg/dL. Yet perceived stress did not change significantly in that analysis.¹⁸ By contrast, a 2024 review of nine trials, with 558 people, did find lower stress scores.¹⁹ Part 3 of the series looks at the herbal research in full.

Safety

In July 2026 the TGA updated its safety advice on ashwagandha. It describes the risk of liver injury as very rare, but real.^20,21 Sudden stomach upsets, such as nausea, vomiting and diarrhoea, have also been reported. Stop taking it and see your doctor if you notice yellowing of the skin or eyes, dark urine, itching or pain under the right ribs. Avoid it if you have a liver condition or are pregnant. Don’t buy it online from overseas either, because those products aren’t regulated in Australia. If you take an antidepressant or other medicine, read our post on natural medicine alongside medication first.

The Evidence Ladder: Tradition, Trials and Safety

In short, here is how the three older practices and remedies in this post compare, layer by layer.

General information only, not individual medical advice. Always discuss supplements and herbal medicines with your treating practitioner.

Should You Get a Cortisol Test?

A cortisol test is worth doing when it will change what you do. Blood, saliva, urine and hair tests each measure something different, and a single morning blood test says little about your daily rhythm. If Cushing’s syndrome is suspected, your GP uses specific tests such as late-night salivary cortisol, 24-hour urine or a dexamethasone suppression test.²

My own rule for any test is simple: do it if it will better inform the treatment plan and get a better result faster. For a tired, stressed person with an obvious cause, testing often won’t change the first steps. However, it earns its place when the picture is unclear or progress has stalled. Without it, you are only guessing.

We offer cortisol testing as part of our hormone testing, alongside your GP’s role in ruling out medical causes.

How Long Does It Take to Reduce Cortisol?

It varies between people. Certainly, some changes act within the hour: a slow-breathing session or a walk outside can lower cortisol the same day. However, lasting change takes longer, and the trials reviewed here ran for four weeks to four months. Expect progress to be uneven: the path to progress is never linear, and consistency matters more than intensity.

When Should You See Your GP?

See your GP if you have rapid weight gain with a rounded face, purple stretch marks, easy bruising or muscle weakness, or blood pressure that won’t settle. Equally, see them if stress, low mood or anxiety are affecting daily life. If you are struggling to cope or feel unsafe, call Lifeline on 13 11 14.

The Bottom Line on How to Reduce Cortisol

Ultimately, learning how to reduce cortisol is mostly about lowering the load on your stress system, not chasing one number. Sleep, slow breathing, time outdoors, sensible exercise and less caffeine have the strongest support. Supplements play a supporting role, and some carry real safety warnings.

We want the body to do most of the work; our job is to create the right conditions for it. For more on stress, sleep and mood, visit our mood and stress page.

Frequently Asked Questions

How can I reduce cortisol quickly?

Slow belly breathing for five minutes, a 20-minute walk outside, and skipping the afternoon coffee are the quickest evidence-based steps. They can lower the stress response within the hour. Lasting change comes from better sleep and a daily practice, kept up over weeks rather than days.

Can a vitamin reduce cortisol?

No single vitamin has good evidence for it. Omega-3 fats have the best trial evidence for a lower cortisol response; magnesium and vitamin C are often promoted with weaker data. However, correcting a genuine deficiency helps the stress system work properly, which is why testing can be worth discussing.

What foods reduce cortisol?

No food lowers cortisol directly. Instead, regular meals with protein, oily fish, vegetables and wholegrains steady blood sugar, which avoids the cortisol spikes that come with skipped meals and sugar crashes. Cutting back on caffeine and alcohol helps too, mainly through better sleep.

Does exercise raise or reduce cortisol?

Both. Hard exercise raises cortisol briefly, which is normal. In contrast, easy to moderate movement tends to reduce it. Problems come from intense training without enough sleep, food or recovery, so walk most days and keep hard sessions purposeful.

What are the signs of high cortisol in women?

Mostly the same as in men: poor sleep, feeling wired but tired, cravings and more weight around the middle. Women may also notice cycle changes or worse PMS, and in perimenopause more abdominal weight and 3 am waking. Our cortisol belly post covers the midlife picture.

Is adrenal fatigue real?

Not as a medical diagnosis. A systematic review of 58 studies found no consistent evidence for it. The symptoms people describe are real, though, and HPA-axis dysregulation, a stress response out of rhythm, is the more useful way to understand them.

Is ashwagandha suitable for lowering cortisol?

Not for everyone. Ashwagandha has a long history in Ayurveda and some trial evidence for lower cortisol, but the TGA reports a very rare risk of liver injury. Avoid it in pregnancy or with a liver condition, don’t buy it online, and check with your practitioner first, especially if you take other medicines.

References

Sources 1 to 7

1. McEwen BS. Protective and damaging effects of stress mediators. N Engl J Med. 1998;338(3):171-179. doi.org/10.1056/NEJM199801153380307 ↩︎
2. Ceccato F, Terzolo M, Gatto F, et al. Who and how to screen for Cushing’s syndrome: the position statement of the Italian Society of Endocrinology. J Endocrinol Invest. 2026;49(3):461-481. doi.org/10.1007/s40618-025-02758-3 ↩︎
3. Cadegiani FA, Kater CE. Adrenal fatigue does not exist: a systematic review. BMC Endocr Disord. 2016;16(1):48. doi.org/10.1186/s12902-016-0128-4 ↩︎
4. Leproult R, Copinschi G, Buxton O, Van Cauter E. Sleep loss results in an elevation of cortisol levels the next evening. Sleep. 1997;20(10):865-870. doi.org/10.1093/sleep/20.10.865 ↩︎
5. Rogerson O, Wilding S, Prudenzi A, O’Connor DB. Effectiveness of stress management interventions to change cortisol levels: a systematic review and meta-analysis. Psychoneuroendocrinology. 2024;159:106415. doi.org/10.1016/j.psyneuen.2023.106415 ↩︎
6. Ma X, Yue ZQ, Gong ZQ, et al. The effect of diaphragmatic breathing on attention, negative affect and stress in healthy adults. Front Psychol. 2017;8:874. doi.org/10.3389/fpsyg.2017.00874 ↩︎
7. Khanal MK, Saunders P, Nguyen K, et al. Meditation and workplace health: a systematic review and meta-analysis of mental and cardiometabolic outcomes among employees. Health Psychol Rev. 2026:1-30. doi.org/10.1080/17437199.2026.2652892 ↩︎

Further sources, 8 to 14

8. Hunter MR, Gillespie BW, Chen SY. Urban nature experiences reduce stress in the context of daily life based on salivary biomarkers. Front Psychol. 2019;10:722. doi.org/10.3389/fpsyg.2019.00722 ↩︎
9. Saoji AA, Raghavendra BR, Manjunath NK. Effects of yogic breath regulation: a narrative review of scientific evidence. J Ayurveda Integr Med. 2019;10(1):50-58. doi.org/10.1016/j.jaim.2017.07.008 ↩︎
10. Pascoe MC, Thompson DR, Ski CF. Yoga, mindfulness-based stress reduction and stress-related physiological measures: a meta-analysis. Psychoneuroendocrinology. 2017;86:152-168. doi.org/10.1016/j.psyneuen.2017.08.008 ↩︎
11. Hansen MM, Jones R, Tocchini K. Shinrin-yoku (forest bathing) and nature therapy: a state-of-the-art review. Int J Environ Res Public Health. 2017;14(8):851. doi.org/10.3390/ijerph14080851 ↩︎
12. Qiu Q, Yang L, He M, et al. The effects of forest therapy on the blood pressure and salivary cortisol levels of urban residents: a meta-analysis. Int J Environ Res Public Health. 2022;20(1):458. doi.org/10.3390/ijerph20010458 ↩︎
13. Hill EE, Zack E, Battaglini C, et al. Exercise and circulating cortisol levels: the intensity threshold effect. J Endocrinol Invest. 2008;31(7):587-591. doi.org/10.1007/BF03345606 ↩︎
14. Cole EL, Grillo AR, Vrshek-Schallhorn S. Habitual caffeine use is associated with heightened cortisol reactivity to lab-based stress in two samples. Psychosom Med. 2024;86(8):730-737. doi.org/10.1097/PSY.0000000000001334 ↩︎

Final sources, 15 to 21

15. Madison AA, Belury MA, Andridge R, et al. Omega-3 supplementation and stress reactivity of cellular aging biomarkers: an ancillary substudy of a randomized, controlled trial in midlife adults. Mol Psychiatry. 2021;26(7):3034-3042. doi.org/10.1038/s41380-021-01077-2 ↩︎
16. Pickering G, Mazur A, Trousselard M, et al. Magnesium status and stress: the vicious circle concept revisited. Nutrients. 2020;12(12):3672. doi.org/10.3390/nu12123672 ↩︎
17. Mukherjee PK, Banerjee S, Biswas S, et al. Withania somnifera (L.) Dunal – modern perspectives of an ancient Rasayana from Ayurveda. J Ethnopharmacol. 2021;264:113157. doi.org/10.1016/j.jep.2020.113157 ↩︎
18. Albalawi AA. Dual impact of Ashwagandha: significant cortisol reduction but no effects on perceived stress – a systematic review and meta-analysis. Nutr Health. 2025;31(4):1395-1408. doi.org/10.1177/02601060251363647 ↩︎
19. Arumugam V, Vijayakumar V, Balakrishnan A, et al. Effects of Ashwagandha (Withania somnifera) on stress and anxiety: a systematic review and meta-analysis. Explore (NY). 2024;20(6):103062. doi.org/10.1016/j.explore.2024.103062 ↩︎
20. Therapeutic Goods Administration. Withania somnifera (ashwagandha) and very rare risk of liver injury. Safety update, 7 July 2026. tga.gov.au ↩︎
21. Björnsson ES. Common causes of drug-induced liver injury in 2025. Turk J Gastroenterol. 2026;37(9):924-935. doi.org/10.5152/tjg.2026.26361 ↩︎

General information only, not individual medical advice. Always discuss supplements and herbal medicines with your treating practitioner.