Cannabis has long held a reputation as a chill pill. You take it, you relax. It’s a cultural staple, a medical recommendation, and a weekend ritual for millions. But the narrative is shifting. New research suggests that for regular users, the very substance meant to lower stress might actually be keeping your body in a low-grade state of alarm every morning.
It’s not a conspiracy. It’s biology.
Researchers from Oregon State University dug into the hypothalamic-pituitary-axis, or HPA axis. This is the body’s central command center for stress. It orchestrates the release of cortisol, the hormone that tells your brain and body it’s time to move, react, or flee. The team wanted to see if daily cannabis use disrupts this delicate hormonal dance.
The answer, published in the journal Cannabis, is yes.
The study focused heavily on the cortisol awakening response (CAR). This is the sharp spike in cortisol levels that typically hits within 30 minutes of waking up. It’s nature’s way of booting up your system, prepping you for the day. Healthy CAR is essential. It’s supposed to rise, peak, and then settle.
But here is where it gets complicated.
The OSU team didn’t just look at whether the spike happened. They looked at the baseline. They recruited 39 frequent cannabis users and a control group of 43 people who used the drug rarely or never. Over two weekdays, participants collected saliva swabs at three specific intervals: immediately upon waking, 30 minutes later, and again at 9 p.m. They also filled out surveys about their mental health, sleep quality, and perceived stress.
The results were stark.
The size of the spike—the actual rise in cortisol over that 30-minute window—was similar in both groups. The mechanism still works. The car engine still revs. The difference? Regular cannabis users started the day with a higher floor. Their baseline cortisol levels upon waking were significantly higher than non-users.
“Our research suggests cortisol levels upon awakening may serve a neurobiological marker of problematic cannabisuse,” says behavioral neuroscientist Anita Cservenko.
Think of it like a thermostat. In non-users, the temperature (stress hormones) starts low and rises to a functional level. In frequent users, the thermostat is broken. The room is already hot when they wake up, and the spike just adds fuel to the fire.
Chronic exposure to high cortisol is no joke. It’s linked to anxiety, heart disease, and metabolic issues. So why is this happening? The study design—observational, snapshot-in-time—means we can’t prove causality. We don’t know if cannabis causes higher cortisol, or if people with naturally higher cortisol just use more cannabis to cope.
The relationship is likely bidirectional. High stress drives use. Use drives higher stress. It’s a loop.
“We would need to study the same groups over a longer period to understand cause and effect, but this provides an important starting point,” Cservenko notes.
This matters because use is exploding. In the U.S., nearly 29% of 19-to-30-year-olds reported using cannabis in the last 30 days. That figure has almost doubled in the last two decades. More telling is the frequency of use. Over 10% of that same demographic used cannabis 20 or more days in that same month. That number has more than doubled in just 15 years. We are dealing with a massive shift in consumption habits, and the physiological fallout is still being mapped.
It’s also worth noting that the science isn’t entirely consistent. Another study earlier this year suggested that chronic use might actually blunt the CAR, leading to lower morning cortisol. Cservenko acknowledges this contradiction. She suggests it points to nuances in analytic strategies and sample characteristics rather than a clear, uniform biological rule.
The body is complex. Cannabis is complex. The intersection of the two is messy.
What remains clear is that for those waking up every day with their stress system already primed, the habit might be costing more than they think. It’s not just about getting high. It’s about how long it takes to come down, and what the morning feels like while you’re stuck in the gap.
The data is just one piece of the puzzle. But for the millions waking up before the alarm goes off, wondering why they feel wired before their first sip of coffee, the question isn’t whether it helps. It’s what it’s quietly doing while you sleep.
