People who use cannabis several times a week may be waking up with higher levels of the body’s main stress hormone, according to a new study, even though it doesn’t disrupt the hormone’s usual morning surge the way researchers expected.
What scientists actually tested
Researchers at Oregon State University wanted to know whether regular cannabis use throws off the body’s stress response system, specifically the hypothalamic-pituitary-adrenal axis, which controls the release of cortisol. They focused on something called the cortisol awakening response: the sharp spike in cortisol that normally happens in the first 30 minutes after waking up, which is considered a reliable signal of how well the stress system is functioning.
The study compared 39 adults who used cannabis at least three days a week over the past year against 43 healthy adults who rarely or never used it. None of the participants had any history of a diagnosed mental health condition, which let researchers isolate the effects of cannabis use itself rather than other overlapping issues.
How the testing worked
Participants spit into collection tubes at three points: right when they woke up, 30 minutes later, and again in the evening, on two separate weekdays. They also rated their own stress levels at each of those moments and avoided food, caffeine, alcohol, and cannabis before each sample to avoid skewing the results.
Everyone showed up for an initial lab visit where they passed a breathalyzer test and gave a urine sample to confirm recent drug use patterns, then completed standard questionnaires measuring sleep quality, depression, anxiety and perceived stress.
The surprise: no difference in the morning spike
Going in, researchers expected frequent cannabis users to show a blunted, weaker version of that morning cortisol spike, based on an earlier 2026 study that found exactly that pattern. This study didn’t replicate it. The rise in cortisol during that first half hour after waking was statistically the same between cannabis users and non-users.
The twist: baseline cortisol was already higher
Here’s where it gets interesting. Right at the moment of waking, before the 30-minute spike even happened, cannabis users had meaningfully higher cortisol levels than non-users. And the more cannabis-related problems someone reported experiencing, things like trouble at work, cognitive issues, or health complications, the higher their morning cortisol tended to be.
Cannabis use frequency alone, meaning simply how many days a month someone used, wasn’t linked to this cortisol elevation. It was specifically tied to how much cannabis use was causing real problems in someone’s life.
More stress, more cortisol, but not equally for everyone
Across both groups, people who reported feeling more stressed in the moment also had higher cortisol levels, which is expected and matches how the body’s stress system is supposed to work. But there was a hint, not a rock-solid finding, that this connection between how stressed someone feels and what their hormones are actually doing was weaker in frequent cannabis users compared to non-users. Researchers describe this as speculative but consistent with the idea that regular cannabis use may gradually disconnect the way the body reports stress internally from how it reports it consciously.
Frequent cannabis users in the study also reported worse sleep quality and higher scores for depression, anxiety, and general perceived stress than the comparison group, even though actual sleep duration and wake-up times were nearly identical between the two groups.
Why this matters
The researchers frame the elevated morning cortisol as a possible early warning sign. This biological marker could reflect wear and tear on the stress-response system from repeated cannabis use over time. Similar patterns have shown up with other drugs like alcohol and nicotine, both of which are already linked to disrupted stress hormone regulation with heavy use.
This doesn’t mean cannabis directly causes the elevated cortisol, or that the arrow points only one way. The study was a snapshot in time, not a long-term tracking study, so it can’t determine whether cannabis use is driving the hormone changes, whether people with naturally higher stress-hormone activity are more likely to use cannabis frequently, or some mix of both.
The limits of this research
This was a relatively small study of 82 people, though comparable in size to the few other studies that have looked at this question. Participants were only tracked for two days, and everyone was asked to briefly abstain from substances before testing, which itself could subtly affect stress and hormone readings. The researchers are calling for larger, longer-term studies that track cannabis users over time to nail down cause and effect.
The bottom line
This research adds a genuinely useful data point to a messy, evolving picture of what regular cannabis use does to the body’s stress machinery. The takeaway isn’t “cannabis is dangerous” or “cannabis is fine,” it’s that frequent, heavy cannabis use appears to leave a measurable fingerprint on morning stress hormone levels, particularly among people already experiencing cannabis-related problems in their daily lives. If you’re using cannabis regularly and also dealing with high stress, poor sleep or mood changes, this study is one more reason to have that conversation with a healthcare provider rather than assume it’s a neutral habit.
The information in this article is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always talk with a qualified health care provider about substance use, stress management, or hormone-related health concerns.
