Migraines and Medical Cannabis

An introduction to migraines

Migraines are more than just headaches. Classified as a disabling illness, migraines affect around 10 million people in the UK aged 15-69 years old. Women are more likely to experience migraines than men (1 in 5 women experience migraines, compared to 1 in 15 men). They can occur anywhere from several times a week to once every several years.

These extremely painful headaches are often accompanied by a selection of unpleasant symptoms, from nausea to light sensitivity. Migraines are believed to be caused by temporary changes in the brain, likely due to the involvement of a genetic factor. They can be triggered by things like stress and exhaustion, menstruation, or even certain foods and drinks.

Migraines can cause significant distress, not only due to the severe pain and accompanying symptoms, but also because frequent migraines can prevent people from fully living their lives. There’s currently no cure, though medications are available to ease migraine pain. One area of particular interest is the therapeutic potential of marijuana for headaches and migraines.

What happens when you have migraines?

A migraine is generally classed as a headache with throbbing pain on one side of the head. The pain can become so severe that it can cause nausea and vomiting. People often become extremely sensitive to light and sounds during a migraine, and can even experience vertigo, a tingling in their extremities, sweating, or diarrhoea.

Some people experience sensory symptoms known as an aura beforehand, which warns them that a migraine is coming on. This is a change in perception such as blind spots or flashing lights in the visual field, stiffness, feelings of confusion, or difficulty speaking. It’s possible to experience a migraine aura without the headache, though this is rare.

Migraines without auras are the most common type, but there are many different kinds of migraines, including abdominal migraines (where the pain is in the stomach rather than the head). They can be classified as chronic if the person experiences headaches at least 15 days of the month for at least 3 months, with specific migraine symptoms on 8 of the 15 days.

Medical cannabis and migraines: what does the evidence say?

Cannabis is a flowering plant with various strains, which contain different concentrations of hundreds of chemical compounds known as cannabinoids. Among these compounds are CBD (cannabidiol) and THC (tetrahydrocannabinol), the latter of which is psychoactive.

These cannabinoids in particular have been the subject of increasing interest for decades now, due to their potential to relieve chronic pain. Where other treatments have been ineffective for chronic migraines, cannabinoids could not only reduce acute pain but possibly work as a preventative treatment to reduce the frequency of migraines.

While clinical research into the effects of cannabinoids on both animals and humans has been ongoing for many years, there is still a need for further investigation. Here is a selection of some of the most promising evidence for the use of marijuana for headaches:

  • 2012 – A study at the University of Modena’s Interdepartmental Centre for Research on Headache and Drug Abuse compared nabilone (synthetic THC) to ibuprofen for treating headaches. Nabilone was more effective than ibuprofen at reducing both pain and medication dependence, improving quality of life with rare and mild side effects.1
  • 2016 – A review of research into pain syndromes and the endocannabinoid system suggests that conditions such as migraines are caused by a genetic or acquired endocannabinoid deficiency, with cannabinoid treatments potentially able to mediate symptoms by acting on this system. The theory is supported by findings of significantly different endocannabinoid levels (specifically anandamide) in the cerebrospinal fluid of migraineurs.2
  • 2016 – A retrospective chart review found that migraine frequency decreased from 10.4 headaches to 4.6 headaches a month for migraine patients prescribed medical cannabis. Patients used different forms of marijuana daily, most commonly inhaled – when edible forms were used, some patients experienced negative effects such as excessive sleepiness.3
  • 2017 – A study on female rats found that THC reduced migraine-like pain by mediating CB1 receptors, supporting the use of cannabinoids to treat migraines in humans and implicating CB1 receptors as therapeutic targets for migraine relief.4
  • 2017 – A two-phase Italian study presented at the 3rd Congress of the European Academy of Neurology (EAN) found that doses of cannabinoids below 100mg were ineffective for migraine patients, but 200mg reduced acute pain by 55%. When comparing longer-term use of 200mg of the CBD-THC combination to common migraine medications, the second phase found that CBD-THC was more effective than amitriptyline (40.4% pain reduction, compared to 40.1%).5
  • 2019 – Another retrospective chart review found that 88% of patients experienced an improvement in their headaches after 17-22 weeks of medical cannabis exposure. Average monthly migraine frequency decreased by 42.1%, with significant improvements in sleep quality and mood and reductions in anxiety and opioid medication use. A 20:1 ratio of THC to CBD was significantly more effective than a 1:1 ratio.6
  • 2019 – A study at Washington State University found that patients who inhaled cannabis reported a 47.3% reduction in headache severity and a 49.6% reduction in migraine severity (90% of men reported pain reduction, compared to 89.1% of women). There was no significant difference among strains with higher or lower CBD or THC, but cannabis concentrates like CBD oil were more effective than cannabis flower.7
  • 2020 – A study at the University of Colorado measured the self-reported effectiveness of cannabis for adults actively using cannabis. Of the users who experienced migraines, 76.4% specifically used cannabis to treat their migraines, and reported significantly higher relief when using cannabis (75.82%) compared to non-cannabis treatments (51.01%).8
  • 2020 – A questionnaire-based cross-sectional study explored the use of phytocannabinoids among subgroups of migraineurs. Those who responded to medical cannabis treatment reported lower pain and disability scores and higher quality sleep scores than non-responders. Overall, medical cannabis reduced long-term migraine frequency in over 60% of patients.9
  • 2020 – A study on the effectiveness of cannabis flower in treating headaches used data from the Releaf cannabis-tracking app to determine symptom relief. The majority of users (94%) experienced relief within 2 hours, with symptom intensity reducing by 3.3 points on a scale of 0-10. Strains with 10% THC or higher were most effective for women and younger people with headaches.10 

As the research suggests, cannabis can alleviate and suppress chronic pain such as migraines in appropriate dosages, with THC or combinations being more effective than just CBD for migraines. The concern over the medicinal use of THC is its psychoactive properties, which could negatively affect cognitive and executive function in the long-term.

However, research has also shown that using sub-intoxicating levels of THC in combination with CBD and gradually up-titrating can reduce such side effects while maintaining analgesic action.11 Across studies and reviews, authors commonly concluded that some types of headaches respond better to different dosages and strains of cannabis, recommending future study on specific migraine aspects.

Migraines and the endocannabinoid system

Humans produce endogenous cannabinoids (endocannabinoids) as part of a biological system which includes cannabinoid receptors throughout the body, known as the endocannabinoid system (ECS). Studies suggest that chronic pain conditions, such as migraines, are caused by a dysfunctional ECS.2

The theory is that exogenous cannabinoids (from the cannabis plant) can activate the ECS and stimulate the production of endocannabinoids, thus restoring pain-relieving processes. THC is the main antinociceptive cannabinoid, affecting the ways that the human body’s systems respond to sensory stimuli most strongly by binding to CB1 receptors throughout the nervous system.12

It’s believed that CB1 receptors then affect trigeminal neuron responses in the brain to suppress pain and other migraine symptoms, further suggesting that ECS dysfunction is the reason for failed inhibition of trigeminovascular activity.13-14 If cannabinoids such as THC can reactive the ECS and restrict migraine-causing activity in the trigeminovascular system as suggested, then medical cannabis is a viable treatment for chronic migraines.

While CBD appears to have less of an analgesic effect via the endocannabinoid system, primarily affecting CB2 receptors in the immune system without actually binding to them, it still contributes anti-inflammatory benefits that could relieve migraine symptoms.15 There’s also evidence that CBD can help to reduce migraines by modulating the body’s 5HT1A serotonin receptors, providing anti-depressant and anti-anxiety effects.16-17

While more research into the specificities of the biological causes of migraines and cannabinoid activity is necessary, the historical results of scientific research and anecdotal evidence from migraine patients confirm the pain-relieving potential of marijuana for migraines.

How does cannabis compare to current treatments for migraines?

Migraines can be difficult to treat, especially if over-the-counter painkillers aren’t managing the pain. If you experience migraines for more than 5 days a month, it’s best to visit your GP to discuss potential causes and treatments. These could include:

  • Lifestyle changes – if you identify a migraine trigger, such as stress or a certain food, you should aim to resolve or avoid this trigger to prevent migraines
  • Medications – your doctor can prescribe triptan painkillers, anti-emetics, or combinations
  • Physical therapyacupuncture for tension migraines, or electrical nerve stimulation

Not everyone will have access to or even desire to undergo physical therapies, and migraine medications often run the risk of becoming addicted to painkillers. The previously mentioned research shows that medical cannabis for migraines is often a more effective alternative for pain reduction, and allows patients to avoid developing a dependency on traditional painkillers.

The issue with medicinal cannabis is that the potential side effects can vary depending on the dosage, delivery method, and the individual themselves. This is why self-medication is not recommended, and standardised dosing overseen by a specialist is required. In the UK, medical professionals on the General Medical Council’s Specialist Register can prescribe medicinal cannabis for chronic pain when other treatments are ineffective.

If you experience chronic migraine pain and would like to try medical marijuana treatments for headaches, you can book a consultation with Cannabis Access Clinics. Our expert clinicians will assess your eligibility and decide whether medicinal cannabis would be a suitable treatment for your migraines. Click here if you would like to know more about this process.


1) Pini LA, Guerzoni S, Cainazzo MM, Ferrari A, Sarchielli P, Tiraferri I, Ciccarese M, Zappaterra M. (2012). ‘Nabilone for the treatment of medication overuse headache: results of a preliminary double-blind, active-controlled, randomized trial’. The Journal of Headache and Pain, 13(8), pp. 677-684.

2) Russo EB. (2016). ‘Clinical Endocannabinoid Deficiency Reconsidered: Current Research Supports the Theory in Migraine, Fibromyalgia, Irritable Bowel, and Other Treatment-Resistant Syndromes’. Cannabis and Cannabinoid Research, 1(1), pp. 154-165.

3) Rhyne DN, Anderson SL, Gedde M, Borgelt LM. (2016) ‘Effects of Medical Marijuana on Migraine Headache Frequency in an Adult Population’. Pharmacotherapy, 36(5), pp. 505-10.

4) Kandasamy R, Dawson CT, Craft RM, Morgan MM. (2017). ‘Anti-migraine effect of ∆9-tetrahydrocannabinol in the female rat’. European Journal of Pharmacology, 818, pp. 271-277.

5) Congress Review. (2017) European Medical Journal Neurology, 5(1), pp. 12-29.

6) Mechtler L, Bargnes V, Hart P, McVige JW, Saikali N. (2019). ‘Medical Cannabis for Chronic Migraine: A Retrospective Review’.  Neurology, 92 (15 Supplement), P3.10-015.

7) Cuttler C, Spradlin A, Cleveland MJ, Craft RM. (2019) ‘Short- and Long-Term Effects of Cannabis on Headache and Migraine’. The Journal of Pain, 21(5-6), pp. 722-730.

8) Gibson LP, Hitchcock LN, Bryan AD, Bidwell LC. (2020). ‘Experience of migraine, its severity, and perceived efficacy of treatments among cannabis users’. Complementary Therapies in Medicine, 56, 102619.

9) Aviram J, Vysotski Y, Berman P, Lewitus GM, Eisenberg E, Meiri D. (2020) ‘Migraine Frequency Decrease Following Prolonged Medical Cannabis Treatment: A Cross-Sectional Study’. Brain Sciences, 10(6), p. 360.

10) Stith SS, Diviant JP, Brockelman F, Keeling K, Hall B, Lucern S, Vigil JM. (2020) ‘Alleviative effects of cannabis flower on migraine and headache’. Journal of Integrative Medicine, 18(5), pp. 416-424.

11) MacCallum CA, Russo EB. (2018) ‘Practical considerations in medical cannabis administration and dosing’. European Journal of International Medicine, 49, pp. 12-19.

Hohmann AG, Suplita RL 2nd. Endocannabinoid mechanisms of pain modulation. AAPS J. 2006;8(4):E693-E708.

12) Hohmann AG, Suplita RL 2nd. (2006). ‘Endocannabinoid mechanisms of pain modulation’. The AAPS Journal, 8(4), pp. 693-708.

13) Akerman S, Holland PR, Goadsby PJ. (2007). ‘Cannabinoid (CB1) receptor activation inhibits trigeminovascular neurons’. The Journal of Pharmacology and Experimental Therapeutics, 320(1), pp. 64-71.

14) Sarchielli P, Pini LA, Coppola F, Rossi C, Baldi A, Mancini ML, Calabresi P. (2007). ‘Endocannabinoids in chronic migraine: CSF findings suggest a system failure’. Neuropsychopharmacology, 32(6), pp. 1384-1390.

15) Pertwee RG. (2008) ‘The diverse CB1 and CB2 receptor pharmacology of three plant cannabinoids: delta9-tetrahydrocannabinol, cannabidiol and delta9-tetrahydrocannabivarin’. British Journal of Pharmacology, 153(2), pp. 199-215.

16) O’Sullivan SE. (2016). ‘An update on PPAR activation by cannabinoids’. British Journal of Pharmacology, 173(12), pp. 1899-1910.

17) Sartim AG, Guimarães FS, Joca SR. (2016). ‘Antidepressant-like effect of cannabidiol injection into the ventral medial prefrontal cortex-Possible involvement of 5-HT1A and CB1 receptors’. Behavioural Brain Research, 303, pp.218-227.



Though an exact cause of migraines isn’t known, we have a better understanding of how migraines work, and what can trigger them episodically. When a stimulus that you’re sensitive to triggers the trigeminal nerve, it releases chemicals that impair the normal function of blood vessels and nerves.

This results in extreme over-sensitivity to sensory stimuli and an inability to regulate pain properly. It’s believed that this neurological dysfunction and sensitivity to particular triggers for it are at least partially genetic. So, if adult family members experience migraines, you’re more likely to as well.

There is a wide variety of triggers for migraines, which vary from person to person. The most common are dietary triggers, such as not eating or drinking enough, or eating or drinking certain things, like cheese, chocolate, coffee, or alcohol. Strong smells can also be common triggers.

Emotional triggers include stress, shock, or excitement, while hormonal triggers include menstruation, pregnancy, and menopause. Physical or environmental triggers include lack of sleep, bright lights, weather changes, strenuous physical activity, poor posture, and medications.

Since migraines are often hereditary, it’s possible for family members to have the same triggers for their headaches. However, the ways that a particular substance, activity, or environment affect the trigeminovascular system can be completely different in severity from one person to the next.

If you experience severe migraines, which occur on more than five days out of a whole month, then you should visit your GP. However, if you experience a sudden blinding pain, muscle weakness, seizures, a high temperature, or slurred speech, then you should go to A&E right away.

There isn’t one specific physical test to diagnose migraines, as they (and their symptoms) can be unpredictable. To help your doctor identify a pattern in your headaches, you should keep a ‘migraine diary’ where you can document the onset times, severity, and duration of pain and other symptoms.

You should also record what you were doing that could possibly have triggered the migraine, and any painkillers you took to treat it (including which type, how much, and how often). Frequent use of painkillers can actually cause a headache, which could make them ineffective against a migraine.

When you see your GP, they’ll carry out a physical exam to test your vision, co-ordination, and reflexes. They’ll consider your full medical history and attempt to determine whether these are primary or secondary headaches (caused by an underlying condition with pain as a symptom).

Your doctor might also refer you for further testing, including blood tests and scans such as an MRI, CT, and X-ray, and maybe even a lumbar puncture (spinal tap). Based on your symptoms, medical history, and the results of these tests, they can determine which (if any) type of migraine you have.

In cases of chronic migraines where symptoms are difficult to control or a diagnosis isn’t clear, you may have to see a neurologist for further specialist assessment and treatment. You will only receive a migraine diagnosis if the headaches you experience can’t be better accounted for by anything else.

Medicinal cannabis is a highly regulated substance, and qualified medical professionals can only prescribe it to treat severe chronic pain. Under current legal restrictions and clinical guidance, all other possible treatments must have been pursued via your primary care provider beforehand.

If you’ve been experiencing chronic migraines that severely impact your quality of life, and no other treatment option has given adequate relief from the pain, then you may be eligible to try medical cannabis. Ask your GP to refer you to a specialist like Cannabis Access Clinics, or contact us directly.

You’ll have to provide your medical history via your GP, and we’ll assess your eligibility free of charge. If you’re eligible for cannabis treatment for migraines, we’ll proceed with a detailed consultation to determine a suitable plan, carefully considering any other medications you need.

Since medicinal cannabis is strictly regulated in the UK and prescriptions and studies are monitored by a Controlled Drugs Accountable Officer, you can be sure that you’ll receive high-quality CBD/THC formulations and that your treatment plan is properly designed by experts to meet your needs.

The efficacy of cannabis for migraines has a strong success rate, but it can vary from one individual to another. If nothing else is helping you to cope with your intense migraines, it’s worth trialling medicinal cannabis to see if it can relieve the pain and reduce the frequency of your migraines.

Why not contact us to find out whether this treatment would be a valid option for you? If you do participate in cannabis studies for migraines, you’ll be helping to lead the way towards the eventual wider availability and legalisation of medicinal cannabis for more people with other ailments.



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