THC-CBD Vaporized Cannabis Reduced Acute Migraine Symptoms in a Randomized Trial
A vaporized cannabis preparation containing both THC and CBD reduced pain and other acute migraine symptoms more consistently than placebo in a randomized, double-blind clinical trial. The findings suggest potential for a specific cannabinoid combination as an acute migraine treatment—not as proof that cannabis prevents migraines or provides established long-term relief.
The research was first posted as a 2024 medRxiv preprint and was later published in Headache: The Journal of Head and Face Pain. In the published randomized trial, researchers at the University of California, San Diego enrolled 92 adults with migraine. Participants treated up to four separate migraine attacks, using one of four vaporized cannabis preparations in a randomly assigned order: approximately 6% THC, approximately 11% CBD, a combination of 6% THC and 11% CBD, or a placebo flower containing negligible THC and CBD.
The study recorded outcomes at one, two, 24 and 48 hours after treatment. In total, 247 migraine attacks were treated. Participants used a standardized vaporization procedure at the beginning of an attack and reported pain and related symptoms through a smartphone application. The trial was registered at ClinicalTrials.gov.
Combination treatment performed best on key measures
Two hours after vaporization, the THC-CBD combination produced pain relief in 67.2% of treated attacks, compared with 46.6% with placebo. It also produced complete pain freedom in 34.5% of attacks, compared with 15.5% with placebo.
The combination was also associated with freedom from the participant’s most bothersome migraine symptom—typically light sensitivity, sound sensitivity or nausea—in 60.3% of attacks, compared with 34.5% with placebo. It improved freedom from photophobia and phonophobia, although the study did not find a significant advantage over placebo for nausea or vomiting.
The THC-CBD preparation was the only treatment to show statistically significant sustained benefits beyond the initial two-hour assessment. Compared with placebo, it was associated with higher rates of pain freedom at 24 hours, freedom from the most bothersome symptom at 24 hours, and freedom from that symptom at 48 hours. The difference in 48-hour sustained pain freedom was not statistically significant.
THC alone also improved two-hour pain relief, with 68.9% of attacks meeting that measure compared with 46.6% with placebo. However, THC alone did not significantly improve two-hour complete pain freedom or freedom from the most bothersome symptom. The CBD-only preparation did not significantly outperform placebo on the main two-hour outcomes.
What the study does—and does not—show
Because the combined preparation performed better than either single-cannabinoid preparation on several outcomes, the results are consistent with the possibility that THC and CBD may have complementary effects. The trial did not, however, establish a specific biological mechanism or prove that the two compounds act synergistically.
The study also does not show that vaporized cannabis is an effective preventive treatment or that using it regularly is safe over the long term. Participants treated individual attacks rather than following a preventive regimen, and the researchers did not assess risks such as medication-overuse headache or cannabis use disorder over extended periods.
The cannabis used in the trial was also highly standardized. The study examined one THC concentration, one CBD concentration and one THC-to-CBD ratio. The flower contained very small amounts of minor cannabinoids and no terpenes, so the findings cannot automatically be applied to commercial cannabis products, which may differ substantially in potency and chemical composition.
Side effects and clinical context
No serious adverse events were reported. Nevertheless, psychoactive effects were more common with THC-containing preparations. Participants receiving THC alone reported more euphoria, cognitive impairment and subjective feelings of being high than those receiving the THC-CBD combination. Sleepiness, dizziness, impaired focus and throat irritation were also reported.
Cannabis products are not approved by the U.S. Food and Drug Administration for migraine treatment. The FDA’s consumer guidance on cannabis and CBD notes that CBD can interact with medications and may carry risks including drowsiness and liver injury. People considering cannabis for migraine should discuss it with a healthcare professional, particularly if they take other medicines, have a history of substance-use problems, are pregnant or breastfeeding, or have conditions that could make inhaled products unsafe.
Overall, the trial provides controlled evidence that a low-potency vaporized preparation containing both THC and CBD can relieve some symptoms during an acute migraine attack, with benefits lasting into the following day for several measures. Larger, multicenter studies are still needed to determine how the treatment compares with established migraine therapies and whether repeated use offers meaningful benefits without unacceptable long-term risks.
