If you have spent any time on the internet lately, you have almost certainly encountered a version of this claim: your cortisol is too high, and it is ruining your face, your waist, your sleep, and your mood.
The “cortisol trend” is having a moment. Cortisol face. Cortisol belly. Cortisol-blocking supplements. Videos with millions of views explaining that if you fix your cortisol, you fix your life. Most of the specific claims are not supported by rigorous research. Cortisol face, in the way social media describes it, is not a recognized medical phenomenon. Cortisol-blocking supplements have limited evidence. And yet the underlying instinct people are following is not entirely wrong. Chronic stress is real. It has measurable effects on the body. And cortisol is deeply involved in how those effects unfold.
What the cortisol conversation is missing — almost entirely — is the system in your body that is supposed to help turn the stress response off. That system is one you have almost certainly never heard discussed in a wellness video, and it is the same one we have been exploring throughout this series.
This is the sixth piece on how the endocannabinoid system relates to the other chemical messengers in your body. So far we have looked at endorphins, oxytocin, dopamine, serotonin, and GABA.
What Cortisol Actually Is
Cortisol is a steroid hormone produced by the adrenal glands, which sit atop each of your kidneys. It is the primary output of what physiologists call the HPA axis — the hypothalamic-pituitary-adrenal axis, the body’s main neuroendocrine stress response system.
Here is how the HPA axis works, in plain terms. When your brain perceives a threat — real, imagined, physical, or emotional — a region called the hypothalamus releases a signaling molecule called CRH (corticotropin-releasing hormone). CRH travels to the pituitary gland, which releases another signaling molecule called ACTH. ACTH travels through the bloodstream to the adrenal glands, which respond by releasing cortisol. That cortisol then does the work of the stress response: mobilizing glucose, raising blood pressure, sharpening attention, suppressing immune activity in the short term, and shifting the body away from non-urgent functions like digestion, reproduction, and long-term repair.
In an acute crisis — a car swerving toward you, a job interview, a hard conversation — this system is exactly what you want. Cortisol rises, you respond, the threat passes, cortisol falls. Homeostasis restored.
In a chronic crisis — an unrelenting job, an unhealed trauma, a financial pressure that never resolves, a caregiving load that never lets up — the system was not designed for that. Cortisol stays elevated. The systems it suppresses stay suppressed. And over time, the collateral effects begin to accumulate: disrupted sleep, mood disorders, weight changes, inflammation, cardiovascular strain, cognitive impairment, and immune dysregulation. Chronic cortisol elevation is one of the mechanisms by which stress becomes disease.
This is where the endocannabinoid system enters — because it is one of the body’s primary systems for turning cortisol off.
What Endocannabinoids Actually Are
For readers new to the series: endocannabinoids are lipid-based molecules produced by your body throughout the central and peripheral nervous systems. The two most studied are anandamide (AEA) and 2-arachidonoylglycerol (2-AG). They bind to CB1 and CB2 receptors, which are distributed widely throughout the brain, immune system, and other tissues. Together with the enzymes that build and break them down, they form the endocannabinoid system — one of the body’s primary regulatory networks, involved in mood, pain, appetite, sleep, immune function, memory, and — as this article will explore — the stress response itself.
If you’d like the fuller foundation, our back-to-basics guide on endocannabinoids covers the fundamentals.
The Endocannabinoid System Is the Brake on the Stress Response
Over the past two decades, a substantial body of research — much of it from the labs of Matthew Hill (University of Calgary), Sachin Patel (Vanderbilt), and Jeffrey Tasker (Tulane) — has established that the endocannabinoid system is a primary regulator of the HPA axis. And its dominant role is inhibitory. It puts the brake on stress.
The mechanism operates on two timescales.
At the baseline level, anandamide provides ongoing tonic inhibition of HPA axis activity. In the amygdala — the brain region responsible for detecting threat — anandamide levels remain steady under non-stressed conditions, quietly dampening the amygdala’s excitability and keeping the threshold for a stress response reasonably high. When something threatening happens, one of the first molecular events is a rapid drop in anandamide, driven by the activity of an enzyme called FAAH (fatty acid amide hydrolase). Anandamide levels fall. The brake releases. The amygdala fires. The stress response begins.
At the acute level, the story continues. Once the stress response is underway and cortisol begins to rise, the elevated cortisol itself triggers a rapid increase in 2-AG in the hypothalamus and other regulatory regions. That 2-AG binds CB1 receptors on the neurons that were driving the HPA axis, and it tells them to stop. This is called fast feedback inhibition, and it is one of the mechanisms by which cortisol turns its own release off. The endocannabinoid system, in other words, is not just involved in ending the stress response. It is one of the mechanisms cortisol uses to end its own release. The stress system has a built-in off switch, and the off switch is made of endocannabinoids.
This is a remarkable piece of biological architecture. Research published in journals including Neuropsychopharmacology, Journal of Pharmacology, and Neuroscience has established this feedback loop across multiple laboratories and species. It is not a fringe finding. It is one of the most well-characterized functions of the endocannabinoid system in the brain.
What Happens When the Brake Wears Out
Here is where the story becomes clinical.
Chronic stress does not just elevate cortisol. It degrades the systems that regulate cortisol — and the endocannabinoid system is one of the systems it degrades. Under chronic stress, CB1 receptor expression in the stress centers of the brain begins to decline. Anandamide levels tend to fall. The feedback loop that ought to turn the stress response off begins to work less efficiently. And the result is a nervous system that runs hot, with a stress response that fires more easily and terminates less completely.
This is not a hypothetical mechanism. It has been documented across dozens of studies in humans and animals. And it is directly relevant to one of the most challenging conditions in modern psychiatry.
Post-Traumatic Stress Disorder and Endocannabinoid Deficiency
In 2013, a research team led by Alexander Neumeister at NYU School of Medicine, working with colleagues at Yale, Harvard, the Department of Veterans Affairs National Center for PTSD, and UC Irvine, published a study using PET brain imaging to look at the endocannabinoid system in people with PTSD.
The results were striking. People with PTSD had substantially lower serum anandamide than trauma-exposed people who did not develop PTSD, and they had significantly higher CB1 receptor availability in brain regions involved in fear and threat processing — particularly the amygdala. The interpretation is now widely accepted: when endocannabinoid levels drop, the brain compensates by producing more receptors, hoping to catch what little signal is available. It is like a hearing aid getting louder in response to fading input.
Subsequent research has extended these findings. A large study of individuals exposed to the September 11, 2001 attacks found lower anandamide levels in those who developed PTSD compared to those who did not. Animal studies have shown that reduced anandamide predicts increased stress-induced anxiety, and that boosting anandamide can reverse those effects. Research from Vanderbilt has linked PTSD to 2-AG deficiency specifically, with implications for how the disorder is treated.
The theory that has emerged from this body of work is called clinical endocannabinoid deficiency — the idea that in some people, the endocannabinoid system’s normal capacity to regulate stress, mood, and threat processing is compromised, and that this compromise contributes to conditions including PTSD, migraine, fibromyalgia, and certain forms of anxiety. It is not yet a settled clinical framework, and the science continues to develop. But it is a hypothesis grounded in real data, and it is one of the reasons cannabinoid therapies are being investigated seriously for stress-related conditions.
This is also part of why the veteran community has been at the center of the modern cannabinoid research conversation. Approximately fifteen percent of U.S. veterans treated in VA outpatient PTSD clinics report using cannabis to manage their symptoms. Many report significant subjective relief. The research is not yet at the point of definitive clinical recommendation, but the mechanism — a stressed endocannabinoid system compensated by exogenous cannabinoids — is a plausible one, and it is the target of active research.
Realm of Caring has been part of this conversation. In September 2024, we co-organized the Validated Voices Summit in Washington, D.C. with Americans for Safe Access, US Pain Foundation, and Veterans Initiative 22 — bringing patient and provider voices, including veterans, into the federal policy conversation about cannabis access. The advocacy work matters because the biology matters. When people whose endocannabinoid systems have been altered by chronic trauma report that a plant compound helps them, the mechanism that would explain their experience is well-documented in the peer-reviewed literature. Their reports are not incidental to the science. They are consistent with it.
Where Cannabis Fits — and Where It Doesn’t
There is an apparent paradox in the cortisol-cannabis relationship that is worth being honest about.
Acute cannabis use — particularly THC — has been shown in multiple studies to raise cortisol, not lower it. This can sound contradictory. If the endocannabinoid system is a brake on the stress response, why would activating it with an outside compound push the stress response up?
The answer is that the endogenous endocannabinoid system operates locally and precisely, engaging specific circuits at specific times. Exogenous THC activates CB1 receptors broadly, including in regions where the natural role of the receptor may be different from what its activation by a plant compound produces. In addition, the acute cortisol response to THC appears to attenuate with regular use, suggesting the body adapts. And CBD, which does not bind CB1 strongly, appears to affect the stress axis differently than THC does, with some studies suggesting anxiolytic effects that operate without an initial cortisol spike.
The takeaway is not that cannabis is a straightforward stress remedy. It is that the endocannabinoid system, the plant compounds that engage it, and the body’s stress response interact in ways that depend on dose, timing, individual physiology, and which specific compounds are involved. This is part of why cannabinoid therapies for stress-related conditions require care, personalization, and — ideally — coordination with providers who understand what the research does and does not yet show. Our care team exists precisely for that reason.
Where the Two Systems Differ
To pull the comparison fully into view:
Chemistry. Cortisol is a steroid hormone, built from cholesterol. Endocannabinoids are lipid signaling molecules, built from fatty acids. They are entirely different classes of molecules with entirely different biosynthetic pathways.
Type of messenger. Cortisol is a hormone — released into the bloodstream, acting on target tissues throughout the body via slow-acting genomic mechanisms. Endocannabinoids are neuromodulators — released locally at synapses, acting on nearby cells, with effects that unfold in seconds to minutes.
Direction of action. Cortisol is the primary activator of the stress response’s effects on the body. The endocannabinoid system is the primary brake on the stress response’s initiation and continuation. They are, in a real sense, opposing forces in one of the body’s most important regulatory systems.
Timescale. Cortisol operates over hours and days. Endocannabinoid signaling operates over milliseconds to minutes. This difference in timescale is part of why the two systems can regulate each other — the fast system can rapidly turn the slow system off.
Why This Matters
The takeaway from the cortisol conversation is not that cortisol is bad. Cortisol is essential. Without it, you could not respond to threats, mobilize energy, or maintain basic biological function. The problem is not the hormone. It is the system’s regulation.
Your body has a stress hormone. It also has a system that is supposed to help turn it off. When that off-system is intact and functioning well, the stress response does what it evolved to do — it activates when needed, and it terminates when the threat passes. When that off-system is compromised, by chronic stress or by trauma, the consequences show up in some of the most difficult conditions in modern medicine.
The endocannabinoid system is one of those off-systems. It is not a wellness fad. It is not a cannabis-related curiosity. It is a fundamental part of how the body regulates stress, and it is one of the systems modern life may be quietly wearing down in ways researchers are only beginning to fully map.
If you are exploring cannabinoid therapies for anxiety, sleep, seizures, or another condition, our care team is available worldwide at no cost. If you are a candidate for participation in observational research, our Observational Research Registry — the largest of its kind in the United States, and an ongoing partnership with Johns Hopkins University — welcomes patients from anywhere in the world. And our Research Library holds more than 800 peer-reviewed studies on cannabinoids and human health.
Coming Up Next
Future pieces in this series will examine how endocannabinoids interact with norepinephrine and the alertness system, with histamine and inflammation, and with other major chemical messengers. Each comparison shows a different facet of the same underlying network — your body’s internal regulatory chemistry, of which the endocannabinoid system is one of the most far-reaching and least talked-about parts.
