Fibromyalgia is a debilitating disease accompanied by widespread pain. In the United States it is estimated that 3.1% of the population suffers from this condition, with no highly effective therapeutic measures or medications to help. (3)
One hypothesized pathophysiology of fibromyalgia is an endocannabinoid deficiency, begging the question of whether or not cannabinoids from plants such as the Cannabis sativa could help bring about relief to those experiencing the painful symptoms of fibromyalgia.
In this article we will review what is currently known about fibromyalgia and the endocannabinoid system (ECS), using published scientific studies to try and help answer the question, can CBD oil help help with fibromyalgia pain?
What is Fibromyalgia?
Fibromyalgia is defined as widespread pain lasting for longer than three months that includes palpation or tenderness at 11 or greater of 18 specific tender points. (3)
Symptoms include frequent widespread pain, fatigue, depression, and difficulty sleeping. As you can imagine, this condition can lead to a poor quality of life, making understanding the cause(s) of and treatment for fibromyalgia crucial for a large portion of our society.
The causes of fibromyalgia remain unknown, although it is known that depression, psychological stress, certain genes, obesity, and a number of other factors tend to increase the likelihood that someone will develop fibromyalgia symptoms.
Fibromyalgia is associated with several physiological factors, such as increased pro-inflammatory cytokines and reduced anti-inflammatory cytokines, disturbances in neurotransmitters linked to mood, including dopamine and serotonin, changes in pain processing in the brain, small fiber pathology, and reduced reactivity of the HPA (hypothalamus-pituitary-adrenal) axis to stress. (3) It is unknown if these factors are the cause or result of fibromyalgia.
Unfortunately, it is difficult to treat the pain and symptoms of fibromyalgia, with very few patients responding well to current treatments.
With how widespread, debilitating, and poorly understood fibromyalgia is, more studies are needed to further explore the pathology of and treatment for this condition.
One promising area of research is linked to marijuana and the compounds found within, which exert their effects through interacting with the endocannabinoid system.
What is the Endocannabinoid System?
Discovered in the 1990s, the endocannabinoid system (ECS) has been found to play a role in the modulation of stress, pain, and the immune system.
The ECS has three functions in mammals: stress recovery and equilibrium, energy balance, and immune regulation. (3) Endocannabinoid receptors (CB1 and CB2 receptors) exist throughout the peripheral and central nervous system, as well as in immune tissues and cells.
It is believed that this system is involved in inflammation and the immune response, memory and cognition, antinociception (pain blocking), nausea and committing, and endocrine function.
The ECS is composed of endocannabinoid receptors, endocannabinoids, and enzymes found throughout our bodies and in our brain.
Fibromyalgia and the Endocannabinoid Deficiency Hypothesis
There exist a number of subjective pain syndromes whose causes for and effective treatment of remain elusive. Of these disorders, three exist that share multiple commonalities: migraine, irritable bowel syndrome (IBS), and fibromyalgia. (1)
These three conditions all display hyperalgesia (a heightened sensitivity to pain) and central sensitization (when the nervous system is in a state of persistent high reactivity), as well as populations that overlap, which has led some researchers to believe that they may share an underlying pathophysiology.
One hypothesized pathophysiology of these three conditions is a clinical endocannabinoid deficiency (CED), although thus far there is no clear and definitive evidence to support this theory. (1,3)
The idea is this – all humans have something referred to as an underlying endocannabinoid tone which reflects the level of endocannabinoids anandamide (AEA) and 2-arachidonoylglycerol (2-AG), their metabolism and production, as well as the relative abundance and condition of cannabinoid receptors.
If the overall function of the ECS were to decrease, it would likely lead to a lower threshold for pain, as well as changes in mood, sleep, and digestion as these systems are all intricately tied to the ECS.
If the endocannabinoid deficiency theory holds true, there are conditions, possibly genetic or environmental, under which endocannabinoid tone become deficient, leading to these pathophysiological syndromes.
Evidence for Clinical Endocannabinoid Deficiency
Migraines, fibromyalgia, and IBS are all hyperalgesic conditions that often generate negative diagnostic workups, have patients who display anxiety and depression, and have a high level of overlap in the population.
In a 2016 study published in Cannabis and Cannabinoid Research, Russo compiled current research in order to test the CED hypothesis in migraines, IBS, and fibromyalgia. (1) Here we will focus on the support for the role of the ECS in fibromyalgia.
Many authorities now believe that neuropathic pain is at the root of fibromyalgia, with secondary hyperalgesia, where patients experience lowered thresholds for pain in areas adjacent to the primary areas of pain.
Studies have observed hyperalgesia in the spinal cord is association with central endocannabinoid hypofunction, finding that endocannabinoids reduced the hyperalgesia. (1) This means that an endocannabinoid deficiency has been linked to the same kind of lowered threshold for pain found in fibromyalgia patients, and was helped with endocannabinoids.
Does Cannabis Help with Fibromyalgia?
Cannabis sativa has been widely used for pain relief for millennia. With the recent movement of legalizing medical and recreational marijuana in multiple states, more research has been funded to further understand how the compounds in this plant function and how they may help a variety of medical conditions.
Cannabis sativa is a plant that encompasses both marijuana and hemp plants, with marijuana plants containing higher levels of THC, the psychoactive cannabinoid, and hemp plants containing lower THC levels and higher cannabidiol (CBD) levels.
CBD and THC are two of over 80 cannabinoids and hundreds of chemical compounds found in cannabis plants. These cannabinoids are known as phytocannabinoids and they are capable of interacting with the ECS.
This interaction with the ECS with phytocannabinoids and synthetic cannabinoids offers hope to millions suffering from a variety of conditions currently poorly treated with therapies and medications, with numerous clinical trials demonstrating that these cannabinoids may offer promise for those suffering from chronic neuropathic pain from a variety of origins. (3)
Below we will review the studies conducted thus far on cannabinoids and fibromyalgia pain.
THC Reduces Subjective Pain in Fibromyalgia Patients
In a 2006 study published in Current Medical Research and Opinion, THC was administered to nine fibromyalgia patients in doses of 2.5-15 mg/day for three months. (8) Only 4 patients completed the study, with other subjects leaving early due to side effects.
Of those 4 patients who completed the study, all had significant reductions in subjective pain. Unfortunately this was not a placebo controlled study, and there were very few subjects who completed the trial.
Nabilone, a Synthetic Cannabinoid, Reduces Pain and Anxiety Associated with Fibromyalgia
Nabilone is a semisynthetic THC analog and CB1 agonist that has 10 times higher potency than THC.
In a 2008 study published in The Journal of Pain, 40 patients with fibromyalgia were given either 1mg of nabilone or placebo daily for 4 weeks. (5)
As compared with the placebo, the patients in the nabilone group experienced a significant improvement in pain, anxiety, as well as the overall impact of fibromyalgia, based on the Fibromyalgia Impact Questionnaire.
Cannabis Use Helps to Relieve Symptoms in Patients with Fibromyalgia
In a 2011 study published in PloS One, a questionnaire regarding cannabis use and perceived benefits on a range of symptoms was given to fibromyalgia patients, along with the Fibromyalgia Impact Questionnaire (FIQ), the Pittsburgh Sleep Quality Index (PSQI), and the Short Form 36 Health Survey (SF-36). (4)
There were 28 cannabis users and 28 non-users included in the study based on similar demographics and clinical variables.
2 hours after cannabis use, VAS scores showed a significant reduction of stiffness and pain, an increased sense of well being and somnolence, and increased relaxation. Additionally, the mental health component summary score from the SF-36 was significantly higher in cannabis users when compared to non-users. There was no significant difference found in other measures, including the FIQ, PSQI, and other SF-36 domains.
This study showed beneficial effects of cannabis use on some of the symptoms of fibromyalgia.
Does CBD Oil Help with Fibromyalgia?
Studies that have included whole-plant cannabis have found benefits for those suffering from fibromyalgia, but as of yet there have not been any studies that have specifically targeted fibromyalgia pain with CBD-only products.
Unlike THC, which has a strong affinity for endocannabinoid receptors, CBD has a weak affinity and appears to impact the ECS through a variety of different mechanisms.
One way that CBD impacts the ECS is through boosting the levels of endocannabinoids that our bodies produce. If fibromyalgia is indeed due to a deficiency in the endocannabinoid system, the endocannabinoid boosting effects of CBD may offer relief.
Further studies need to be conducted in order to determine what effect, if any, CBD has on fibromyalgia, however the studies thus far do support the idea that fibromyalgia may be the result of an endocannabinoid deficiency, and if this is the case, it is possible that CBD products could help.
The benefits of CBD without THC revolve not only around fewer side effects due the the psychoactive effects of THC, but also the wider legality and availability of CBD-only products.
Studies conducted thus far on CBD have found few side effects, and most individuals tolerate CBD quite well. (6,7) It is important to check with your doctor before adding in a new supplement, including CBD. CBD has been found to interact with certain medications.