Do you feel overwhelmed by daily tasks? Catch yourself thinking negative or pessimistic thoughts? Blame your high cortisol levels, influencers would have you believe.
Online, cortisol—commonly called the “stress hormone”—is a hot topic and frequent scapegoat. Type “cortisol levels” or “howtoreducecortisol” into TikTok, and you’ll be met with hundreds of millions of posts, name-dropping the hormone as responsible for everything from a puffy face (#cortistolface) to a bloated midsection. There are just as many hacks for how to handle it. Beauty and wellness brands have also jumped on the cortisol bandwagon and released products, sometimes marketed as “anti-stress,” that claim to reduce cortisol.
Considering that stress has become a bogeyman for everything that ails us, it’s perhaps not surprising that people are zeroing in on tamping down the hormone aligned with it. But what exactly is cortisol? Do we really need to be fixated on our levels? And when can we fairly blame it for health issues?
How cortisol works
The cortisol fixation has made its way from the internet to doctors’ offices. And people have questions. “In all my years of being a doctor, I’ve never heard cortisol being mentioned so much by patients,” says Dr. Molly McBride, an ob-gyn and women’s health specialist in New York City. “Now with TikTok running amok, everybody is asking for cortisol checks.”
Cortisol is a hormone synthesized from cholesterol that is produced by the adrenal glands. When we are stressed or in fight-or-flight mode, the brain kicks off a process that results in the body producing cortisol. “Cortisol then stimulates our body to increase blood pressure and metabolize fats, carbohydrates, and protein so we have the energy to respond to the stressor,” says Dr. David Kim, a dermatologist in New York City. Cortisol is essential for regulating circadian rhythms and reacting to internal and external stressors. “It really is an adaptive hormone,” critical for our acute stress response and the recovery from it, says Rajita Sinha, a neuroscientist and professor of psychiatry at Yale School of Medicine. We all have cortisol, in other words, and we all need it.
The highs and lows of cortisol
It’s normal for cortisol levels to rise and fall throughout the day. This pattern is called the diurnal cycle, says Sinha: cortisol is highest in the morning, then plummets in the afternoon (which is why you’ll sometimes get a post-lunch energy slump). It’s lower in the evening, before bedtime. Short-term spikes help us deal with physical and emotional stressors—running away from a tiger, say, or its modern-day equivalent, receiving a distressing work email—which is not a bad thing. “Cortisol triggers blood sugar so muscles have glucose to function,” says Dr. Gillian Goddard, an endocrinologist in New York City. These quick bursts “increase your alertness in the brain to make good decisions.” Cortisol also goes up when we’re sick in an attempt to help recruit the immune system.
When cortisol is concerning—and when it’s not
If cortisol stays elevated consistently, the blood-sugar spike it sets off can lead to weight gain around the midsection. It can also keep you up at night; people with persistently higher cortisol tend to have problems falling or staying asleep.
Because cortisol can affect the dopamine and serotonin levels in the brain, it can also have an impact on mood, and higher levels have been linked to mental-health conditions like depression and anxiety, says McBride.
Levels can also dip too low. When that happens for an extended period of time, “it’s either because the adrenal gland, which produces cortisol, isn’t getting the proper stimulation from the brain, or there’s something actually wrong with the adrenal gland,” says Dr. Caroline Messer, an endocrinologist in New York City. Very low cortisol levels can cause symptoms including weight loss, fatigue, a lack of appetite, and low blood pressure and blood sugar, says Goddard.
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Consistently high cortisol levels are sometimes linked to certain diseases. If cortisol is two to four times higher than the normal level (which itself is variable) for too long, it can cause Type 2 diabetes, Goddard says. In rare cases, high cortisol can be an indication of Cushing’s syndrome (caused by a benign tumor in the pituitary gland). “The classic picture of Cushing’s is weight gain in the midsection, skinny arms with muscular atrophy, dark wide purple stretch marks on the belly and thighs, sleep disruptions, and new onset mood changes like depression or anxiety,” says Goddard. A large swollen face, irregular distribution of fat, and the development of a hump between the shoulders are additional signs, says Kim.
Just like cortisol, Cushing’s disease is much-discussed on social media. Doctors including Goddard and Messer have more patients, particularly young women, asking to be tested for it more than ever. “A lot of people are diagnosing themselves with Cushing’s when they don’t have it,” says Messer.
Calculating your cortisol levels is challenging
At-home cortisol tests exist, but doctors doubt their accuracy and utility. By using various blood, saliva, and urine tests, endocrinologists are best equipped to get a comprehensive picture of a patient’s cortisol profile and what it means.
Before testing, your specific cortisol-related issue needs to be defined—“you can’t just be generally concerned about your cortisol,” says Messer—and because levels can shift throughout the day, timing matters. Generally, to diagnose a problem, doctors want patients to check their cortisol levels late at night (between 11 p.m. and midnight) and first thing in the morning between 6 a.m. and 8 a.m. A number of conditions and medications can impede the testing process. For example, “oral contraceptives can elevate cortisol levels and mimic stress-like conditions,” says McBride; patients who are pregnant, undergoing menopause, or who have PCOS also generally have higher levels, making testing more challenging.
Sometimes the testing itself can pose a problem. “Even the act of drawing blood, if it’s something that makes you nervous, can raise your cortisol level,” says Goddard. Your doctor will work with you to get the most accurate results.
Cutting through the noise
As name-checking cortisol has become more commonplace, so have the misconceptions around it. Take “cortisol face,” the social-media moniker for facial puffiness supposedly linked to high cortisol. High levels of cortisol can cause inflammation, increased perspiration, and sebum production, which can lead to acne flare-ups, says Kim, but the bloating is often due to behavior precipitated by stress. “When we are stressed, we snack more and crave food that tends to have higher salt and sugar content that can lead to bloating and swelling of the face,” says Kim.
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As for the claims that you can actually feel your cortisol spiking? Not possible, experts say. “You can experience symptoms associated with elevated cortisol like increasing heart rate, sweating, or anxiety, but they are not specific to high cortisol,” says McBride.
Then there’s so-called adrenal fatigue, which refers to a notion that adrenal glands can burn out and become unable to produce cortisol. Doctors say it has no basis in science. “It is a colloquial term, and there is absolutely nothing in medical literature that supports it,” says Goddard. Plus, it’s physiologically impossible, says McBride. “So long as you’re eating you have some cholesterol, you’re going to be making cortisol,” she says. “Adrenal fatigue has become a catchall term for people who just aren’t feeling well.”
Should you try to lower your cortisol?
It’s important to remember that cortisol rises and falls; testing and tracking it or taking supplements that claim to address it is usually unnecessary. “The idea that the stress in our day-to-day lives is raising our cortisol levels to the point of causing long-term harm is overstated,” says Goddard.
The best things you can do for your cortisol are the same stress-management tips you already know: maintain a balanced diet that is low in sugar and refined carbohydrates, get enough rest, exercise regularly, and make relaxation a habit, whether through breathwork, meditation, short walks in nature, or another proven tactic. “If engaging in these activities makes people feel better and less stressed, that’s great,” says Goddard. “It doesn’t matter whether they truly lower cortisol levels or not.”
