Can Cannabis Relieve Neuropathic Pain?

More patients than ever are trying cannabis for neuropathic pain and meeting with successful relief of painful symptoms.

Neuropathy is a disease or injury to the nerves. It results in a state of chronic neuropathic pain that affects every aspect of an individual’s way of life. It’s often called “nerve pain” because the condition stems from actual nerve damage. This is often the result of other conditions such as cancer, multiple sclerosis, or diabetes.
Unfortunately, a study in Pain (2013) [1] found that as many as ten percent of Americans suffer from neuropathic pain. In 2021 researchers reported that 20.2% of Americans suffer chronic pain, of which neuropathic pain is one type.  

Neuropathic Pain Caused by Injury

The most common cause of nerve pain is physical injury. Damage to a nerve resulting from an injury can leave it crushed or compressed, causing pain in the area of the injury and radiating to elsewhere. Even after the injury itself has healed, nerve damage can be long lasting. It can take months, or even years, for the nerve to be fully repaired.
Basically any injury that causes a nerve pathway to narrow or compress could become neuropathic. Some common causes of neuropathic pain are:
  • Broken or dislocated bones
  • Injury to tissue, muscles, or joints
  • Slipped discs

neuropathic pain represented by wrist pain

Neuropathic Pain Caused by Disease

Arthritis, and other conditions can cause neuropathy. However, one of the most prevalent causes of neuropathy in the United States is diabetes. The disease often causes mild to severe nerve damage and may lead to “diabetic peripheral neuropathy” (DPN). Around 366 million people worldwide suffer from DPN, since it is a common side effect of diabetes. Fifteen per cent of diabetes patients report painful DPN symptoms.
Auto-immune diseases can also cause neuropathy by attacking nerves and/or the body’s tissues. Nerve damage or compression can occur suddenly, as a result of an infection, or slowly over time. Some examples of neuropathy causing auto-immune diseases include rheumatoid arthritis, lupus, and Sjögren’s syndrome.
Cancer is another leading cause of neuropathic pain. This comes from treatment with chemotherapy and radiation. Both negatively affect the nervous system. Other known causes of neuropathy include:
  • Multiple sclerosis,
  • thyroid problems,
  • carpal tunnel syndrome,
  • alcoholism,
  • and even vitamin B deficiency.

Symptoms of Neuropathy

The symptoms of neuropathic pain can take days, weeks, months or years to develop, and in some cases never go away. People suffering from neuropathy might experience a shooting or burning pain, and even a feeling of numbness. Neuropathy can be as mild as a subtle tingling, and as severe as a stabbing, debilitating pain. Unfortunately, pain can be constant.
Often, neuropathic pain begins once in a while, but becomes chronic over time. Neuropathic pain can also complicate life for a person, leading to loss of sleep, emotional problems, a general feeling of unease, anxiety and stressFurther, even benign conditions can worsen nerve pain, like cold weather or mild contact with the skin.
Overall, the symptoms vary from person to person, and can be very distressing as the condition progresses. All too often, this distress sends neuropathic pain patients to pharmaceutical treatments.

Treating Neuropathy With Pharmaceuticals

Treatment for neuropathic pain can involve a wide variety of pharmaceutical medications. Even with pharmaceuticals, for some, the pain never goes away. Accordingly, this leads to a dependency on opioid medications, that can in turn lasts for yearsWorse, the side effects of these medications can also cause health-related complications, such as muscle rigidity, hormonal dysfunction, constipation, nausea, and more.
Currently, there is no out-right cure for neuropathic pain, since it has such a wide range of causes and can occur in different areas of the body. Additionally, each individual is different, so no single type of treatment is effective for everyoneAccordingly, as the neuropathic pain progresses, patients can sink into depression, and need to solve that as well. So what can be done for a condition that an estimated one in three Americans faces? Well, the increasing legalization of cannabis, and accompanying advancement in research, provides some clarity.
neuropathic pain represented by cortisone injection into wrist

How Cannabis May Treat Neuropathic Pain

Scientists believe cannabis could potentially help the symptoms of neuropathic pain. Essentially, cannabis interacts with the body’s endocannabinoid system. Through this mechanism, cannabis may help relieve neuropathic pain for some patients. Many patients even find that it helps fight the associated depression that comes wiht their painPerhaps most importantly: Cannabis presents an option for a medical treatment with a low-toxicity profile that has fewer side effects – and no risk of overdose – as is all too common with pharmaceuticals. It all functions within the body’s built-in endocannabinoid system.

The Role of the Endocannabinoid System in Pain Management

The human body has a complex endocannabinoid system (ECS). Surprisingly, the system is relatively newly discovered, too. This means new information comes out almost every day. This system contains multiple types of receptors and molecules that respond to external stimuli – In this case, cannabinoids. The cannabinoids in cannabis interact with the ECS through this network of receptors.
Two cannabinoid receptors (CB1 and CB2) classify as ‘G-protein coupled’ receptors‘. They send signals to the cell, and regulate a wide variety of cellular processes. These receptors are also involved in the way the body detects and transmits signals of pain — however, the precise interplay of these mechanisms is still largely unknown by scienceAccordinglyhowever, an interesting study in Neuropsychopharmacology (2018) [2] found that mice with noCB1 receptors in their peripheral nervous system seemed to feel pain more strongly.

Cannabis and The ECS

The cannabis plant contains active cannabinoids that interact with the endocannabinoid system and thereby induce a range of cellular responses in the body. As you likely know, THC and CBD are the two main cannabinoids found in cannabis, though the whole plant also contains a multitude of other helpful, and potentially pain relieving, compounds — like terpenes, and flavonoids.
THC and CBD both stimulate the ECS in different ways. Basically, THC binds to cannabinoid receptors like CB1 and CB2, while CBD has been shown to have affinity for these receptorsCBD also binds to non-cannabinoid receptors and helps modulate receptor pathways.
neuropathic pain represented by patient holding arm in pain

Relieving Neuropathic Pain

Basically, by binding with endocannabinoid receptors, THC produces the pyschoactive high it is so well-known for. But through this same mechanism, it can also affect a person’s experience of pain.
Through activation of the CB1 receptor, THC affects the serotonergic, dopaminergic, and the glutamergic systems, which can relieves pain. Why? Because neuropathic pain is created and sustained through the glutamatergic system. This system is a nerve pathway that actually regulates the stimulation of neurons, much like an on and off switch.
Accordingly, studies show that THC can have a positive, relieving, effect on neuropathic pain in targeted doses.

For example, a study published in Neurology (2018)[3]investigated how THC could help fifteen male patients with chronic nerve pain. They each underwent an MRI brain scan, and then were dosed with fifteen milligrams of THC. Two hours later, researchers gave the subjects another MRI. They found that not only did THC help alleviate pain, but the patients actually self-ranked their discomfort nearly twenty points lower on a one-hundred point scaleThrough the MRI, the scientists discovered that THC changed the connections in the brain that were responsible for processing pain sensations.

Cannabinoids in Conjunction

Multiple cannabinoids are now under study for their effects on fixing neuropathic pain. Of particular interest is how they work together to fight pain. Here’s an example: the intersection of cannabis, nerve injury, and inflammation. THC activates the patient’s receptors, thus alleviating nerve pain. But at the same time, CBD can also help reduce inflammation, which is a common cause of nerve pain due to the narrowing of nerve pathways. Basically, by inhibiting a non-cannabinoid receptor called GPR55, it induces an anti-inflammatory effect.

Study on CBD and Neuropathy

A study [4] published in Current Pharmaceutical Biotechnology (2019), investigated whether or not topical CBD could help treat peripheral neuropathyResearchers studied twenty-nine patients, by dividing them into a treatment group and a placebo group.
They found that CBD significantly reduced sensations of intense, sharp pain, as well as feelings of itchiness and coldAnd, unlike other pharmaceutical treatments for neuropathic pain, the authors noted that no adverse side effects resulted from treatment with topical CBDThis is because unlike THC and its CB receptor-binding abilities, CBD does not cause a psychoactive high.

Cannabis Vs Opioids? Or Cannabis And Opioids?

To date, common pharmaceutical treatments for nerve pain include opioids, anti-depressants, local anesthetics (like nerve blocks), serotonin-norepinephrine reuptake inhibitors and anti-seizure medications. Many of these medications can be accompanied by toxic side effects and can be habit forming. Cannabis may be able to reduce a patient’s dependence on certain medications, or at the very least help lower dosages.
Through human and animal studies, science has also discovered that cannabinoids, taken in combination with opioids (like morphine), can help treat neuropathic painThe information so far is that taken alongside cannabis, patients can relieve pain with lower doses of opioids.
Basically, cannabinoids act on epidermal keratinocytes to enhance the release of pain-relieving opioids. Science has discovered that when cannabinoids activate the CB1 receptor, the pre-synaptic terminal is hyperpolarizedThis works to close the calcium channel, which holds back inhibitory and excitatory neurotransmitters at their synapses. The result? Modulated pain with opioid and serotonin release.
This is big news considering the devastating effects of opioid addiction. For those trying to cut opioid use entirely, however, there’s positive research in that field as well. A study published in Behavioral Pharmacology (2011) [5] found that activators of CB1 and CB2 have a pain-relieving effect comparable to morphine.
neuropathic pain represented by woman holding her foot

Cannabis and Quality of Life For Neuropathy Patients

Scientific research is also finding that cannabis can improve the quality of life of patients suffering from chronic neuropathic pain.
For example, in one study, researchers from the University of California, San Diego investigated cannabis as a treatment for patients with diabetes leg painThe study, published in the Journal of Pain (2015), [6] observed sixteen patients who were suffering from peripheral neuropathy, or otherwise known as diabetes leg painThey split their subjects into two groups, dosing one group with aerosolized cannabis, and the other with a placebo. Their results showed a reduction in pain intensity with the cannabis treatment. However, there was also a short term impact on cognition. Though researchers note that THC does cause a psychoactive effect, which can be experienced as a negative side effect for some, combining THC with CBD may help help minimize it.
Otherwise, a review published in Pain Physician (2017) [7] combed through studies regarding cannabis and pain treatment, and concluded that cannabis-based medicines could be effective for treating the effects of chronic pain, specifically neuropathic painWhile the evidence is still limited, these results are promising. They pave the way for further scientific research.

Other Cannabis Compounds for Potential Pain Relief

THC and CBD aren’t the only cannabinoids that can help patients who are suffering from neuropathic painCBN has been found to have a positive effect on sleep, which is major hurtle for individuals with chronic pain.
But alongside those helpful cannabinoids, cannabis also contains terpenes and flavonoids. Science is still in the process of uncovering all of what these compounds do for the human body, but so far it has presented us with a few clues.Terpenes like beta-caryophyllene, myrcene and pinene have been found to help regulate pain.
Flavonoids also carry potential health benefits, since they can actually interact with the body’s opioid receptorsThough their binding ability is on the weaker side in comparison to opioid drugs, cannabis flavonoids such as vitexin, isovitexin and cannaflavin can do so in such a way to activate opioid signaling.
Flavonoids can also do more than just bind to opioid receptors. They may also be able to alleviate anxiety and slow cancerous growth — which can be helpful for some patients with neuropathic pain stemming from cancer-related treatments.
What we’re seeing is an entourage effect of the many different compounds found in cannabis, which can not only help treat neuropathic pain, but also many of the different factors that arise from the existence of long-term chronic pain — such as anxiety and difficulty sleeping. Here we see the overarching effects of whole plant medicine.