What migraine and headache disorders are
Migraine is a common neurological disorder characterised by recurrent headache attacks lasting 4 to 72 hours, often accompanied by nausea, vomiting, and sensitivity to light and sound. About one third of people with migraine experience aura: transient visual, sensory, or speech disturbances that typically precede the headache phase. Migraine affects approximately 15% of the UK population and is more common in women.
Other primary headache disorders include tension-type headache, the most prevalent, and cluster headache, a rarer but extremely severe condition involving intense unilateral pain with autonomic features. Medication-overuse headache occurs when frequent use of acute pain medicines paradoxically worsens the underlying headache disorder.
The pathophysiology of migraine involves activation of the trigeminovascular system, release of vasoactive peptides including calcitonin gene-related peptide (CGRP), and abnormal cortical excitability. The endocannabinoid system is present throughout pain-processing pathways and brain regions implicated in migraine, including the trigeminal ganglion, periaqueductal grey, and cortex.
Cannabis research on Migraine and headache
One is a 1997 British Medical Association overview that classifies the evidence for cannabis in migraine as far less convincing than for other indications. The remaining three are ISMOKE magazine articles from 2011-2012 containing anecdotal mentions. None of the evidence base pages constitutes clinical evidence.
The published medical literature provides a small but relevant body of human studies.
A randomised, double-blind, placebo-controlled crossover trial of vaporised cannabis for acute migraine, published in 2026, examined four cannabis varieties versus placebo in people with episodic migraine. In this human clinical study, vaporised cannabis outperformed placebo on pain relief and pain freedom at two hours. This is the only completed randomised controlled trial to date that has tested inhaled cannabis as an acute migraine treatment in a controlled human study.
A clinical trial protocol for a tolerability study of a CBD-enriched cannabis herbal extract for chronic headaches in adolescents (CAN-CHA), published in 2024, has been registered but results are not yet available.
A review article on the clinical endocannabinoid deficiency hypothesis, published in 2016, proposed that migraine, fibromyalgia, and irritable bowel syndrome share a common pathophysiological feature of reduced endocannabinoid tone. This remains a hypothesis; it has not been confirmed by prospective human studies measuring endocannabinoid levels before and after migraine attacks.
A randomised controlled clinical trial of aerobic exercise in people with migraine, published in 2019, measured serum anandamide levels and found that exercise increased anandamide and was associated with clinical improvement. This human clinical study provides indirect evidence linking the endocannabinoid system to migraine, but it tested exercise, not a cannabinoid.
Animal research has demonstrated that CB1 receptor activation inhibits trigeminal nociception and CGRP release in animal models of migraine. These findings show biological plausibility but do not constitute treatment evidence.
Compounds studied for Migraine and headache
THC has been studied in one human randomised controlled trial of vaporised cannabis for acute migraine, where it was a component of the tested cannabis preparations. The trial tested whole-plant cannabis, not isolated THC, so the contribution of THC specifically cannot be separated from other compounds in the cannabis tested.
CBD has not been tested in a completed human randomised controlled trial for migraine or headache disorders. Its anti-inflammatory properties have been documented in cell and animal studies. A clinical trial of CBD-enriched extract for adolescent chronic headaches is under way but has not reported results.
Anandamide is an endogenous cannabinoid produced by the human body. Human observational data from a single exercise trial linked higher anandamide levels to migraine improvement, but anandamide is not available as a treatment.
Beta-caryophyllene is a CB2 agonist. Animal research has shown that CB2 activation reduces inflammatory pain signalling. There are no human trials of beta-caryophyllene for migraine.
Limonene has been studied in animal research for anxiolytic and anti-inflammatory effects. No human migraine trial of limonene exists.
Pinene has demonstrated anti-inflammatory effects in cell and animal studies. Human clinical evidence for pinene and migraine is absent.
Limits of the evidence for Migraine and headache
One randomised controlled trial has provided human clinical evidence that vaporised cannabis outperforms placebo for acute migraine pain, but this is a single study with results that have not been replicated independently. The same trial enrolled people with episodic migraine and excluded those with chronic migraine or medication-overuse headache, so the findings do not extend to those populations.
All other human evidence is indirect. The endocannabinoid deficiency hypothesis is biologically plausible and intellectually coherent, but it remains a hypothesis. No prospective human study has demonstrated that people with migraine have measurably lower endocannabinoid levels than people without migraine, or that cannabinoid administration corrects a specific deficiency.
No randomised controlled trial has tested cannabis or cannabinoids for the prevention of migraine. No trial has compared cannabis against standard acute migraine treatments such as triptans, gepants, or nonsteroidal anti-inflammatory drugs.
The long-term effects of regular cannabis use on headache frequency, including the risk of medication-overuse headache or cannabinoid-induced headache chronification, have not been studied.
The evidence base contains no peer-reviewed migraine research. All clinical evidence was sourced from PubMed.
Sources
1. Schuster NM, Wallace MS, Marcotte TD, et al. Vaporized cannabis versus placebo for acute migraine: a randomized, double-blind, placebo-controlled crossover trial. Headache. 2026;66(4):e70025. Study record
2. Chhabra M, Lewis EC, Balshaw R, et al. A multi-centre, tolerability study of a cannabidiol-enriched cannabis herbal extract for chronic headaches in adolescents: the CAN-CHA protocol. PLoS ONE. 2024;19(9):e0290185. Study record
3. Russo EB. Clinical endocannabinoid deficiency reconsidered: current research supports the theory in migraine, fibromyalgia, irritable bowel, and other treatment-resistant syndromes. Cannabis and Cannabinoid Research. 2016;1(1):154-165. Study record
4. Oliveira AB, Ribeiro RT, Mello MT, Tufik S, Peres MFP. Anandamide is related to clinical and cardiorespiratory benefits of aerobic exercise training in migraine patients: a randomized controlled clinical trial. Cannabis and Cannabinoid Research. 2019;4(4):275-284. Study record
5. Rajapakse T, Davenport WJ. Phytomedicines in the treatment of migraine. CNS Drugs. 2019;33(5):399-415. Study record
