What evidence is there that cannabis can benefit my patients with headaches and migraines, and what specific recommendations can I make to patients?
Migraines and other types of severe headaches are a common public health problem. It’s estimated that 14.7% of the global population struggle with migraines or similar neurological disorders.1 Recent data suggest that 1 in 7 Americans (37 million) suffer from these vascular headaches and other types of severe headaches.2 So it’s no surprise that migraines and headaches are among the leading complaints reported in both outpatient and emergency department visits. Women especially are prone to suffering from migraines and severe headaches during their reproductive years, but people throughout the lifespan from the young to the very old may suffer from them. Family history of migraines is a factor in 70% to 80% of cases.2
Symptoms of migraines include severe, throbbing pain localized to one side of the head that may be accompanied by nausea, vomiting, sensitivity to light and sound, dizziness, fatigue, irritability, and general malaise. Migraine sufferers report that their headaches may be triggered by environmental or hormonal factors. Women who struggle with migraines often report that their symptoms coincide with other premenstrual syndrome symptoms. Migraines may present with an aura, otherwise known as a sensory disturbance. Sensory disturbances may be visual in nature and include vision changes, a flash of light, and blind spots or floaters in the field of vision. Auras may also be described as numbness or tingling in the back of the head, face, arms, or hands.3
Conventional treatment for migraines tends to be limited to nonsteroidal anti-inflammatory drugs, analgesic medications such as acetaminophen, antiemetics, and a family of tryptamine-based drugs (more commonly called triptans). Triptans are selective 5-hydroxytryptamine (5-HT) receptor agonists; they have a high affinity for 5-HT1B and 5-HT1D receptors. Stimulation of the 5-HT1B receptors on smooth muscle cells of blood vessels causes cranial vasoconstriction, thereby reducing or alleviating a migraine experience.4
Patients report that triptans may not work every time, cannot be used too often as their efficacy decreases with overuse, and are not without side effects. These include nausea, dizziness, drowsiness, flushing of the skin, numbness, tingling, and burning sensations. Patients also report rebound headaches with the use of triptans.4
When conventional treatments are exhausted, many migraine sufferers seek complementary and alternative therapies for symptom relief. Cannabis is one among the treatments they may turn to not only for relief of symptoms but also for prevention. Once largely supported by anecdotal reports but with little scientific evidence for its efficacy, cannabis therapy for migraine and severe headache is starting to gain traction, with data that the medical and science communities should deem valuable.
A study by Washington State University (WSU) researchers recently published in the Journal of Pain revealed that inhaled cannabis reduced headache and migraine severity by approximately 50%. It was the first study to track headache changes by using archival data retrieved from a free medical cannabis app, Strainprint (https://strainprint.ca). The app allows cannabis patients in Canada to track their symptoms before and after using cannabis
obtained from a dispensary. They can track each cannabis experience by recording the strains and products they use, the dosages, and changes in symptom severity as a result of their experiences. The WSU researchers were able to retrieve data from a large sample of 1,300 patients who used the app more than 12,000 times to report changes in their headache symptoms. An additional 650 patients used the app more than 7,400 times to report changes in migraine severity.5
Other data worth noting from the study included gender differences—more males reported sessions involving headache reduction than did women—and that cannabis concentrates were more effective than cannabis flower for reducing the severity of headaches. “Overuse” headaches, a drawback of regular use of conventional migraine treatments, were not seen with cannabis use. Overall, the study revealed benefits for cannabis users with one possible negative: Patients reported using increased dosages of cannabis over time, pointing to the possibility of tolerance development.5
Migraines May Be Related to a Clinical Endocannabinoid Deficiency
Migraine is one of several chronic pain syndromes that manifest in pathophysiological patterns related to a deficiency in the endocannabinoid system. More commonly known as clinical endocannabinoid deficiency, conditions associated with this deficiency tend to be resistant to conventional treatment, but improve with cannabis treatment. For migraines, evidence suggests that the endocannabinoid anandamide (AEA) potentiates 5-HT1A and inhibits 5-HT2A receptors, thereby demonstrating therapeutic efficacy for acute migraine. Cannabinoids also demonstrate anti-inflammatory effects.6 It should come as no surprise that since THC has a molecular structure similar to AEA, it contributes to effectively treating migraine. However, as research shows, it’s not the only player, and whole plant medical cannabis should be considered in lieu of isolated cannabinoids. Whole plant extractions comprise other cannabinoids such as CBD, terpenes, and more than 400 other compounds that interact synergistically to create what scientists refer to as an “entourage effect” that magnifies the therapeutic benefits of the plant’s individual components. Therefore, the medicinal impact of the whole plant is greater than the sum of its parts.7
For a person suffering from migraines or other types of hyperalgesic symptoms, anything that promotes quick relief of symptoms is preferred. Inhalation offers the fastest onset of all cannabis delivery methods, with effects typically felt within a few minutes.8 Hence inhalation tends to be the more popular delivery method for migraine sufferers.
However, it’s important to educate patients about the pitfalls of smoking cannabis. Smoking exposes the user to heat, ash, and other products of combustion that irritate the mouth, throat, and airway. An alternative way to deliver cannabis via inhalation is vaporization, which allows the user to inhale cannabis without combusting plant material.
There are many vaporizing devices on the market, all of which are designed to heat cannabis flower and/or concentrates to a temperature that’s lower than that produced by combustion. Heat melts the trichomes, or the resin sacs where cannabinoids, terpenes, flavonoids, and other compounds of the cannabis plant reside. The compounds are then released into an airborne vapor that can be inhaled by the user.
There are other factors that should be reviewed when consulting with patients. Advise them to use lab-tested cannabis strains and products to reduce intake of contaminants such as pesticides, mold, and heavy metals. Until there’s better regulation for the manufacture and distribution of vape cartridges and pens, advise against the use of these products. The long-term impacts of inhaling lipids, flavoring compounds, dyes, and cutting agents such as propylene glycol and vegetable glycerin are largely unknown, and the risks associated with using vape cartridges and pens likely extend beyond the recent EVALI vape crisis.9 Suggest that patients use full-spectrum products to benefit from the entourage effect.
To reduce the risk that they will develop tolerance, advise patients to start with a low dose and increase slowly until the desired effect is reached. If they find they are using more and more cannabis with diminishing benefit, a cannabis holiday may be in order. When cannabinoid receptors are activated on a regular basis by phytocannabinoids (eg, THC), the response from the receptors is lessened, which leads patients to use an increased amount of cannabis for desired effect. Thankfully, tolerance is easily mitigated by abstaining from cannabis consumption for anywhere from a few days to a few weeks. Once patients have undergone such a holiday, advise them to once again start with a low dose and increase slowly until symptoms are relieved.
To determine which products and dosages are most effective, recommend that patients use a journal or an app such as Strainprint to track their experiences. Patient experiences vary, but the data suggest that cannabis is certainly a viable treatment option and potential preventive medicine for migraines and severe headaches.
1. Steiner TJ, Stovner LJ, Birbeck GL. Migraine: the seventh disabler. J Headache Pain. 2013;14(1):1.
2. Burch RC, Loder S, Loder E, Smitherman TA. The prevalence and burden of migraine and severe headache in the United States: updated statistics from government health surveillance studies. Headache. 2015;55(1):21-34.
3. Migraine. Mayo Clinic website. Updated January 16, 2020.
4. The role of triptans in the treatment of migraine in adults. The Best Practice Advocacy Centre New Zealand website. Published 2014.
5. Cuttler C, Spradlin A, Cleveland MJ, Craft RM. Short- and long-term effects of cannabis on headache and migraine [published online November 9, 2019]. J Pain. doi: 10.1016/j.jpain.2019.11.001.
6. Russo EB. Clinical endocannabinoid deficiency (CECD): can this concept explain therapeutic benefits of cannabis in migraine, fibromyalgia, irritable bowel syndrome and other treatment-resistant conditions? Neuro Endocrinol Lett. 2008;29(2):192-200.
7. Terpenes and the “entourage effect.” Project CBD website.
8. Devitt-Lee A. What is the best way to take cannabis? Project CBD website.
9. Lee MA, Sigman Z. What should we do about vaping? Project CBD website. Published September 27, 2019.