Cannabis has been used to relieve headaches for thousands of years, and yet rigorous clinical trials on this ancient remedy for head pain have only just begun.
The first double-blind, randomized, placebo-controlled study is now investigating whether cannabis products, like THC and CBD, can actually treat acute migraines in a safe and effective way.
Currently, 20 participants who experience monthly migraines are enrolled in the trial, but researchers at the University of California San Diego hope to enroll at least another 70 volunteers.
Today, despite numerous treatment options, a significant number of people are still suffering from migraines, which can often be debilitating. The throbbing pain, typically located on one side of the head, can last for hours or even days and be accompanied by nausea, vomiting, and extreme sensitivity to light or sound.
Unfortunately, not everyone responds the same to current migraine treatments, and over time, these drugs can stop working for some.
Plenty of patients report turning to cannabis as an alternative, and yet ever since the plant was deemed illegal in the United States, there has been very little research on its potential as a medicine for chronic pain conditions. A lot of what we know is only anecdotal.
"Many patients who suffer from migraines have experienced them for many years but have never discussed them with their physicians. They are, rather, self-treating with various treatments, such as cannabis," says headache neurologist Nathaniel Schuster from UCSD.
"Right now, when patients ask us if cannabis works for migraines, we do not have evidence-based data to answer that question."
For decades, the medical potential of cannabis and cannabinoids has been overlooked in the West, and yet this ignorance is largely a modern phenomenon.
Two thousand years before the common era (BCE), historical documents suggest people in Assyria were using cannabis to "bind the temples" and relieve tension in the head. In ancient Greece, the drug continued to be used for "pain of the ears", and Persian and Arabic texts refer to cannabis as a treatment for headache disorders.
Even in the Middle Ages, prominent physicians were recommending the plant to alleviate head pain.
Hundreds of years later in the US, cannabis entered a dark age of scientific research. Following the Marijuana Tax Act of 1937, possessing or trafficking the material became illegal, though it was still permitted for medical use. That all changed in the 1970s, when the act was repealed and replaced with a new law that officially outlawed its use for any purpose. All that means it's been extremely difficult to study.
Without proper clinical trials, it's unclear whether any derivatives of this plant can work to relieve head pain, and yet many individuals are using the plant for just that. Certainly, the initial results from preclinical trials are promising.
In 2020, a 30-day trial in the US found over 86 percent of patients with headaches and migraines saw an improvement in their symptoms after using cannabis. Other recent surveys in California suggest up to 10 percent of those with headache disorders are turning to the plant for relief.
Yet self-reports and case studies can only give us so much insight. Without a proper control group, it's hard to say whether the therapeutic effects of cannabis are a placebo response or something more.
The first known trial to properly tackle this issue will randomize volunteers into four separate groups. One group will receive a vape with sham cannabis. Another group will take four puffs of cannabis flower containing THC. A third group will take four puffs of cannabis flower containing CBD, and the last group will vape a mix of both THC and CBD.
Researchers will then determine which treatment is best for relieving headache pain, nausea, vomiting and light or sound sensitivity in both the long term and the short term.
Allison Knigge is one of the first to volunteer for the trial. Knigge has experienced piercing migraines since she was a young child, and despite trying several medications, nothing has helped so far.
When she was approached by Schuster about the UCSD trial, she was at her wit's end and willing to try just about anything.
"I am proud and grateful to be part of a study that could lead to more tools in the toolbox for those of us who suffer from migraines," says Knigge.
"It could mean one more option when all other options have not worked. This is truly significant for patients whose lives are disrupted on a regular basis from migraines."
The trial is currently ongoing.