Today, a substantial proportion of medical cannabis users report using cannabis to manage headache and migraine, claiming that it is effective. However, research on the effectiveness of cannabis for these purposes remains sparse. To date, only one clinical trial has been conducted, wherein the effectiveness of nabilone (a synthetic cannabinoid) was examined. In that study, nabilone was found to be more effective than ibuprofen at reducing pain and increasing quality of life.

Expanding Upon the Literature

For a study published in the Journal of Pain, my colleagues and I sought to expand upon this limited literature by examining the short- and long term effectiveness of cannabis on headache and migraine. We obtained anonymous archival data from the medical cannabis app StrainprintTM, which allows medical cannabis patients to rate the severity of their symptoms immediately before and after cannabis use. Specifically, we obtained pain severity ratings immediately before and after cannabis use from more than 1,300 patients using medical cannabis to treat headache and more than 650 to treat migraine across 16 months.

We also obtained information on the percentage of delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) in the cannabis used, the type of cannabis used (flower vs. concentrates), dose, and patient gender. Only sessions in which cannabis was inhaled and in which symptoms were re-rated within 4 hours of use were included. We also only examined sessions for which the THC and CBD concentrations were obtained directly from the cannabis producer. We analyzed data from nearly 20,000 cannabis use sessions.

Significant Relief

The results of our analyses revealed that headache severity ratings were reduced by 47.3%, and migraine severity ratings 49.6%, after cannabis use. While both cannabis flower and cannabis concentrates were associated with significant reductions in headache and migraine, cannabis concentrates produced significantly larger reductions in headache than did cannabis flower. Similarly, while both men and women reported significant symptom relief, men reported larger reductions in headache than did women. These results suggest that cannabis, particularly cannabis concentrates, provide significant and substantial relief from headache and migraine severity.

We also explored potential long-term ramifications of using cannabis repeatedly to manage headache and migraine. Medical cannabis users reported using significantly increased doses of cannabis across time. Further, they reported smaller reductions in headache severity across time but no changes in relief of migraine across time.

Collectively, these results indicate that tolerance to the effects of cannabis may develop over time, and people may require larger doses of cannabis to achieve smaller reductions in headache severity and equivalent reductions in migraine severity across time. In contrast, we found no evidence for the development of medication overuse headache that is often associated with more conventional treatments. Specifically, pre-cannabis use headache and migraine severity ratings did not change across time, suggesting that repeated use of cannabis to manage headache and migraine does not exacerbate baseline headache or migraine severity.

Looking Ahead

Study limitations include the lack of a placebo control group and use of a self-selected sample of people using cannabis to treat headache and migraine. As such, these results likely overestimate the effectiveness of cannabis, and some of the reported symptom relief may be attributed to users’ expectations of pain relief from cannabis. The results are also specific to the effects of inhaled cannabis; further research is needed to examine whether other routes of administration produce equivalent effects. Nevertheless, our findings of nearly 50% reductions in headache and migraine from before to after cannabis use and the lack of evidence that cannabis is associated with medication overuse headache are encouraging. Hopefully, these findings will serve as a catalyst for clinical trials to examine the effectiveness of cannabis flower and concentrates in treating headache and migraine in a more controlled manner.