what are cortisol bellies and cortisol faces? everything we know about the stress hormone

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cortisol 'detoxes' are trending, but scientists say most people don't need to worry they're producing too much cortisol

by sharon kirkey, national post

published may 01, 2025

5 minute read

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5 minute read

join the conversation

what to know about stress hormone behind 'cortisol bellies and faces'

cortisol is produced in response to acute stress, and normally, decreases with less stress. getty images

google searches for cortisol, the body’s main stress hormone, are soaring, up 110 per cent in the u.s. in the past year alone, with “cortisol trigger foods” and “how to do a cortisol detox” ranking as top trending related searches, according to google trends.

many scientists are dismissing it as the latest tiktok pseudoscience fad, insisting that trying to “cleanse” the body of a vital hormone is “neither survivable nor desirable.”

however, some of the claims have some truths behind them, even if twisted out of proportion to promote dubious advice and products to slim a “cortisol face” or “cortisol belly,” other experts said.

cortisol is an important hormone for human functioning, said dr. stan van uum, chief of endocrinology and metabolism at st. joseph’s health care in london, ont. “and, like any hormone, you need the right amount. too much is not good, it causes issues” and too little is also bad.

van uum, who is also a professor of medicine at western university’s schulich school of medicine and dentistry, spoke to national post to help break down the fuss about cortisol, how to tell if one’s cortisol levels may be a bit off and what people can do if concerned.

what is cortisol?

cortisol is a hormone secreted by the adrenal glands, located above each kidney. it helps regulate the body’s immune response and inflammation, helps convert glucose (a form of sugar) into energy and plays an important role in the sleep-wake cycle. cortisol increases in the hours just before wakening to rouse people out of sleep, peaks during the morning and then falls off toward evening so people aren’t too wired before bed. “it follows a daily rhythm,” van uum said.

how does it affect the body?

cortisol is produced in response to an acute stress. it helped early humans flee predators, that “fight-or-flight” state. it also plays a role in wound healing.

when our early ancestors “were subject to a certain issue — let’s say than an animal bites your leg or you fall from a tree and break your arm — you have to get a sufficient blood supply of glucose to the brain, you need to make sure you have some form of clotting and you need to maintain blood pressure,” van uum said.

“those are the kinds of things that cortisol’s acute stress response tries to address. it’s a very good and appropriate stress response,” the kind of stress response people need going into surgery, he said.

the body regulates cortisol via a feedback loop: in response to a stressor, the hypothalamus sends a signal to the pituitary (a pea-sized gland at the base of the brain) to release a hormone that stimulates the adrenal glands to make more cortisol.

when cortisol rises, it sends a message back to the pituitary and hypothalamus that the levels are sufficient and to stop making more. “it’s a feedback system, like the thermostat at home,” van uum said.

normally, cortisol decreases with less stress. “when it becomes an issue is when your cortisol goes up and stays up and doesn’t come down in an appropriate way when the reason for the stress is over,” he said. people with post-traumatic stress disorder can have high levels of cortisol.

what causes cortisol to go up and not come back down?

it’s usually due to some form of stress dysregulation, some form of trauma, van uum said. “we see some patients where the cortisol regulation by the adrenals becomes autonomous, no longer regulated by the pituitary, which is normally the driver of the cortisol increase.” the regulation gets out of whack.

how do you know if your cortisol levels are a problem?

a clear overproduction of cortisol can cause cushing syndrome, a rare hormonal disorder characterized by a “fatty hump between the shoulders, a rounded face and pink or purple stretch marks on the skin,” according to the mayo clinic.

cushing syndrome can be measured in various ways, including via 24-hour urine sampling, or monitoring cortisol levels in saliva samples throughout the day.

too little cortisol, on the other hand, causes adrenal insufficiency. symptoms include low blood pressure, nausea, vomiting, weight loss and lower blood sugars. if left untreated, it can lead to a life-threatening adrenal crisis, “especially if you’re in a situation where your system needs to respond, like an infection or a surgery,” van uum said.

cortisol runs across a spectrum, he said. “you have completely normal (cortisol levels), completely abnormal and a grey area in between.”

the problem is that symptoms like a puffy face or weight gain aren’t very specific. “not every swelling of the face is necessarily cushing,” he said. it could be water retention, for example.

“the cortisol released from everyday stress doesn’t even come close to the levels or duration seen in cushings,” craig doig, an associate professor of metabolic health at nottingham trent university in england, wrote for the conversation.

“‘cortisol belly’ and ‘cortisol face’ might sound catchy,” doig said, “but they reduce incredibly complex biological processes into bite-sized insecurities.”

“the way i look at ‘cortisol detoxification’ is the idea that you want to get your cortisol levels to a lower level,” van uum said. “but we don’t have good data to say, how do we measure the outcome? and how do we make sure your cortisol is at the appropriate level for what your body needs?”

what about cortisol balancing ‘cocktails,’ baking soda baths, supplements or other purported cortisol detoxes?

daily omega-3 supplements over eight consecutive weeks improved burnout in nurses and lowered their morning cortisol secretion, one small, placebo-controlled study found.

a larger study involving 138 sedentary, overweight and middle-aged participants found omega-3s lowered cortisol, slowed “accelerated aging” and decreased depression risk.

other placebo-controlled studies have suggested the herb ashwagandha has stress-relieving effects. some have found that the effects of meditation are larger for people “who might be in need of such stress reduction programs due to a risk for elevated cortisol levels as compared to no-risk samples.”

but van uum said that in most cases, long-term data are lacking.

other hormones, like adrenaline, also increase with stress. “i don’t think we understand all the hormones that play a role” van uum said.

“you have to think about it: are you worried about your cortisol level or are you worried about the stress in your life, that you feel that there is too much to deal with?

“what is it really that you are trying to address,” he said. “does it have to do with stress? are there situations that trigger it? it may be related to glucose levels. it may be related to lack of sleep. are there situations that make you feel better as well?

“is it that taking a bath and relaxing by itself will lower the cortisol?”

doig recommended people get decent sleep, exercise regularly, eat a balanced diet (also regularly) and “relax — a little.”

“and if something feels off, talk to your doctor.”

this article was originally published in the national post on may 1, 2025.

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