A survey of 244 medical cannabis patients with chronic pain found that cannabis use was associated with a 64% decrease in opioid use, fewer medication side effects, and a 45% improvement in quality of life.
Chronic pain patients interested in whether medical cannabis could reduce their need for opioid medications.
64% decrease in opioid use reported after starting medical cannabis
The Backstory
In 2016, Kevin Boehnke walked into a medical cannabis dispensary in Michigan and did something that pharmaceutical companies weren't doing: he asked patients what happened when they started using cannabis alongside their other medications.
The answer was straightforward. They stopped taking so many of them.
The Survey
Boehnke, working with pain researcher Daniel Clauw at the University of Michigan, conducted a cross-sectional retrospective survey of 244 medical cannabis patients with chronic pain who patronized a Michigan dispensary between November 2013 and February 2015. The questionnaire collected demographic information, changes in opioid use, quality of life, medication classes used, and side effects — all before and after initiating cannabis use.
The design was simple. The findings were not subtle.
Medication Changes
What Happened When Chronic Pain Patients Started Cannabis
64%
Decreased opioid use
among 118 patients previously on opioids
45%
Improved quality of life
self-reported across all 244 patients
Fewer
Medication side effects
reported after starting cannabis
Fewer
Total medications
patients reduced overall medication count
Boehnke et al. (2016), J Pain 17(6):739-44
Nearly two-thirds of patients who had been using opioids reported reducing their opioid use after starting cannabis. They also reported fewer side effects from their remaining medications and a meaningful improvement in quality of life.
What This Study Can and Can't Tell You
Supporting arguments
- Large, consistent effect size — 64% opioid reduction is clinically meaningful
- Captures real-world patient behavior that clinical trials miss
- Quality of life improvement reported alongside medication reduction
- Side effect reduction suggests genuine therapeutic substitution, not just adding a drug
- Pattern replicated in multiple subsequent surveys across different states and countries
Limitations and counterarguments
- Self-report survey — no objective verification of medication changes
- No control group — no placebo comparison possible
- Selection bias — patients at a dispensary are pre-selected for positive cannabis attitudes
- Recall bias — patients may overestimate benefit and underestimate harm
- Cannot determine whether opioid reduction was medically appropriate
- Cross-sectional design — cannot establish that cannabis caused the changes
Boehnke et al. (2016), J Pain
This study cannot prove that cannabis caused patients to reduce their opioid use. It can only show that patients report doing so. The distinction matters enormously. People who seek out medical cannabis and patronize dispensaries are already motivated to use cannabis and may have negative feelings about their other medications. They may overestimate cannabis benefits and underestimate its role in their medication decisions.
But the study captured something the clinical trial literature was entirely missing: what patients actually do when they have access to cannabis alongside their prescription medications. Randomized trials can tell you whether cannabinoids beat placebo for pain on a rating scale. Only surveys like this one can tell you whether patients, in their own lives, are choosing cannabis over opioids — and reporting that the trade feels like an improvement.
The Opioid Context
This study landed in the middle of America's opioid crisis. In 2016, opioid overdoses were killing more than 100 Americans per day. The search for anything that might reduce opioid consumption was desperate and urgent. Boehnke's finding — that patients with access to medical cannabis voluntarily reduced their opioid use by 64% — was exactly the kind of signal that policymakers, physicians, and families were looking for.
The finding didn't prove that cannabis is a solution to the opioid crisis. But it suggested that cannabis access might be one piece of a harm reduction strategy — not by being a superior painkiller, but by being a good-enough alternative with a vastly safer side effect profile. Nobody has ever fatally overdosed on cannabis. The same cannot be said for the medications patients were replacing.
The pattern Boehnke documented has since been replicated. Corroon et al. (2017) found that 46% of cannabis users reported substituting cannabis for prescription drugs, with opioids the most commonly replaced category. Bradford & Bradford (2016) found that states with medical cannabis laws showed significant reductions in Medicare opioid prescribing. The individual-level and population-level data pointed in the same direction.
The Substitution Pattern
Drug Substitution
What Patients Replaced
Opioids
64% reduction — the largest category. Patients reported equivalent or better pain control with fewer side effects.
Other medications
Patients also reduced anti-anxiety medications, sleep aids, and anti-inflammatory drugs — suggesting cannabis addressed multiple symptoms simultaneously.
Side effects
Cannabis produced different side effects (cognitive impairment, dry mouth) but patients rated the overall profile as preferable to opioid side effects (constipation, sedation, dependence, overdose risk).
The concern
Unsupervised medication changes carry risks. Abrupt opioid reduction can cause withdrawal. Some patients may be undertreating their pain. Medical supervision of the transition is important.
Boehnke et al. (2016); Corroon et al. (2017)
The substitution pattern raises a practical question for anyone considering this approach: is cannabis a viable harm reduction tool for people on opioids? The evidence, while observational, consistently suggests yes — for some patients, in some circumstances, with appropriate medical guidance. The key is that it should be a discussion with a physician, not a solo decision. Abrupt opioid discontinuation is dangerous, and not all pain responds equally to cannabinoids.
Key Takeaways
Medical Cannabis Use Is Associated With Decreased Opiate Medication Use in a Retrospective Cross-Sectional Survey of Patients With Chronic Pain
Boehnke KF, Litinas E, Clauw DJ (2016) · The Journal of Pain
Related Research
Key studies in this area
Should I replace my opioids with cannabis?
This study shows that many patients choose to do so and report positive outcomes. But it's not a recommendation. Opioid discontinuation should be managed by a physician — abrupt cessation can cause dangerous withdrawal. Cannabis doesn't work for all types of pain, and some patients need opioids. The best approach is a conversation with your prescriber about whether cannabis might allow a gradual opioid dose reduction.
Is cannabis really safer than opioids?
By most measures, yes — for the specific risk of fatal overdose. No confirmed death from cannabis overdose alone has ever been recorded. Opioids kill tens of thousands annually. But cannabis carries its own risks: cognitive impairment, dependence potential, psychiatric effects in vulnerable individuals, and driving impairment. "Safer" doesn't mean "safe."
Why is this a survey instead of a clinical trial?
Because clinical trials of cannabis as an opioid substitute are extremely difficult to conduct. Schedule I restrictions, ethical concerns about randomizing patients away from established pain treatment, and the complexity of studying real-world substitution behavior all make RCTs impractical for this question. Surveys capture behavior that trials can't.
What the researchers found
Researchers surveyed 244 medical cannabis patients with chronic pain at a Michigan dispensary about how starting cannabis changed their medication patterns and quality of life.
Among participants, medical cannabis use was associated with a 64% decrease in opioid use (based on 118 patients who had previously used opioids). Patients also reported a decreased number of medications overall, fewer medication side effects, and a 45% improvement in quality of life.
The findings suggest that many chronic pain patients are substituting medical cannabis for opioids and other medications, and perceive the benefit and side effect profile of cannabis as superior.
Why it matters
In the context of the opioid crisis, any intervention that helps chronic pain patients reduce opioid use while maintaining or improving quality of life is significant. This study provides patient-level data supporting what population-level studies (linking medical cannabis laws to reduced opioid overdoses) have suggested.
The numbers in context
244 patients surveyed. 64% decrease in opioid use (n=118 opioid users). 45% improvement in quality of life. Decreased number of total medications. Fewer medication side effects reported.
How the study worked
An online cross-sectional retrospective survey of 244 medical cannabis patients with chronic pain who patronized a Michigan dispensary between November 2013 and February 2015. Participants self-reported changes in opioid use, medication use, quality of life, and side effects before and after starting cannabis.
What this study cannot tell us
This was a self-reported retrospective survey with no control group or objective verification of medication changes. Dispensary patients who chose to respond may not represent all medical cannabis users. Selection bias is likely: patients who found cannabis helpful were probably more likely to continue visiting the dispensary and to participate. The survey design cannot determine whether cannabis actually caused the opioid reduction.
How to read the evidence
This is a self-reported retrospective survey with no control group. While the findings are compelling, the study design is subject to selection bias and recall bias, making the evidence preliminary.
When this study was published
Published in 2016. Research on cannabis as an opioid alternative has continued to grow, with mixed results from more rigorous study designs.
The bigger picture
This study contributes to a growing body of evidence suggesting that medical cannabis may serve as an opioid substitute for some chronic pain patients. While the evidence is still largely observational, the consistency across multiple study types (patient surveys, state-level analyses, insurance claims data) is notable.
Questions still open
- Does cannabis truly substitute for opioids, or do patients who reduce opioids also have less pain for other reasons? What are the long-term outcomes for chronic pain patients who switch from opioids to cannabis?
Common questions
Can cannabis replace opioids for chronic pain?
Is cannabis safer than opioids for pain?
Read the original research
Medical Cannabis Use Is Associated With Decreased Opiate Medication Use in a Retrospective Cross-Sectional Survey of Patients With Chronic Pain.
The journal of pain, 17(6), 739-44
Citation
Boehnke, Kevin F; Litinas, Evangelos; Clauw, Daniel J. (2016). Medical Cannabis Use Is Associated With Decreased Opiate Medication Use in a Retrospective Cross-Sectional Survey of Patients With Chronic Pain.. The journal of pain, 17(6), 739-44. https://doi.org/10.1016/j.jpain.2016.03.002