How Does Cannabis Affect the Brain’s Pain Center?

The most common reason that patients explore medical cannabis is for help with chronic pain. The causes of chronic pain are complex and can be related to a number of medical conditions, as well as lifestyle and cardiometabolic health.

Medical cannabis patients may find that using cannabis products can reduce pain. Based on feedback and online reviews, cannabis can be an effective way to lower the volume or intensity of pain for a temporary period of time. Medical marijuana can put the pause button on pain for a period of 3-7 hours, depending on the potency and intake method.

You may know some people who are successful in finding relief from chronic pain because of how cannabis affects their bodies. However, not many people understand how it actually works and why cannabis consumption for pain can be more effective than using other substances for pain relief.

The Endocannabinoid System: A Key Player in Pain Regulation.

If ever there was a rationale supporting the use of cannabinoids for wellness, it is that human beings have cannabinoid receptors in our bodies. The Endocannabinoid System, or ECS, performs a number of functions in the body. But one of the most important roles it plays is to manage pain signals.

There are two receptors in the body, CB1 and CB2, which are located throughout but primarily within the human central nervous system (CNS). They operate like switches, turning on or shutting off different physiological functions.

While CB2 receptors play a role by signaling the immune system and inflammation processes, it is the CB1 receptors that have the greatest influence on your mood and pain perception, or how much pain you feel and where it is located in the body.

Your cannabinoid receptors adjust the intensity of pain signals. It works like this: when you experience pain, the CB1 and CB2 receptors respond, dampen the transmission of pain signals, and trigger an immune system response that also tries to reduce inflammation in the affected area(s).

If you have chronic pain that you find very uncomfortable, consider that your ECS is working overtime to try to reduce that pain. What you are feeling is only a portion of the discomfort you could feel without your endocannabinoid system, which is one of the known impacts between cannabis and the brain.

Exploring the Interaction Between Cannabis and Pain Receptors

Most of the clinical studies about pain management and cannabis focus on cannabidiol (CBD) and dela-9-tetrahydrocannabinol (THC). There are actually over two hundred different cannabinoids known, but more research is needed to understand how they work and their potential therapeutic benefits.

Research suggests that THC and CBD can help modulate pain perception. No pain medication or alternative health method can cure chronic pain. But what it can do is reduce the severity of pain. For some people, that temporary relief of pain can drastically improve their mobility, sleep, and overall quality of life.

But how does cannabis actually work when used for pain relief? After consuming THC, the cannabinoids from the cannabis plant affect the brain and the central nervous system by binding with CB1 and CB2 receptors. Particularly the receptors responsible for processing the experience of acute pain. It reduces discomfort for a period of time.

The THC in cannabis works to reduce the sensation of peripheral pain because it binds to CB1 receptors in cells located in the rostral ventromedial medulla area of the brain. That part of the brain is responsible for pain modulation. When those CB1 receptors interact with cannabinoids, it decreases sensitivity to pain.

One study in 2013 found that even low doses of cannabis could help reduce neuropathic pain. The intake method discussed was vaporized cannabis. A different study in 2021, “Effect of cannabis on oxaliplatin-induced peripheral neuropathy among oncology patients: a retrospective analysis,” reported a 34% reduction in daily pain for patients with diabetes and HIV after consuming smokable cannabis.

What is interesting is that some cannabis strains may actually increase pain sensitivity. That is why it is important to research the strains you plan to use carefully. A 2010 study, “High frequency medical cannabis use is associated with worse pain among individuals with chronic pain,” sparked discussion about the long-term use of cannabis (versus prescription medications).

While it is well known that prescription opioid medications can increase pain sensitivity, it is possible that people who develop cannabis use disorder (excessive use of cannabis) may experience the same problem. Over time, it seems that the human body can develop a tolerance to any type of pain medication, making it less effective. This is why physicians suggest that medical cannabis should be used in conjunction with lifestyle changes and other therapies for long-term pain management.

Differences Between Cannabis and Prescription Pain Medications

Cannabis users often consider changing from prescription pain medications to medical marijuana because they may find commonly prescribed pain drugs to be less effective over time. When a patient has developed a resistance or tolerance for pain medications, doctor-supervised cannabis may provide better results.

Fear of side effects and health risks is also a strong reason why people explore medical marijuana after using conventional medications for a long period of time. The following types of medications are commonly prescribed for neuropathic and other types of pain:

Anti-convulsants

For nerve pain, anti-convulsant medications are thought to be the most effective approach, with drugs like Lyrica (pregabalin) and Neurontin (gabapentin) commonly prescribed. For some patients, this class of prescription drugs can be very effective, but they can also present with undesirable side effects, like chronic fatigue, gastrointestinal or stomach upset, dizziness, and sometimes blurred vision.

Nonsteroidal Anti-Inflammatory Drugs

Patients with chronic pain are often prescribed NSAIDs, which include medications like Ibuprofen and Naproxen. While these medications can be effective, they may also cause a variety of serious side effects, including bleeding stomach ulcers, kidney damage, and an increased risk of heart attack or stroke.

Acetaminophen

Tylenol is a brand name most people know and trust for pain relief, and stronger varieties of Acetaminophen are available by prescription only. One of the risks of taking prescription-grade Acetaminophen is liver damage if it is taken in excessive doses, which makes it a significant risk factor for individuals who use it long-term for pain relief.

Opioids

Some of the most well-known pain medications fall in this class, including Morphine, Oxycodone, and Hydrocodone. What is also well understood is that long-term use of opioid medications can cause patients to develop a tolerance to where the medications are no longer effective for pain relief.

Opioids have significant side effects and risks that make patients hesitant to use them for chronic pain symptoms. Some of those side effects include constipation, drowsiness, symptoms of nausea, dangerous levels of sedation (respiratory depression), and a high potential for addiction and drug dependence.

Corticosteroids

While corticosteroids can be effective for pain management, drugs like Prednisone and Dexamethasone can have side effects such as weight gain, hyperglycemia (increased blood glucose), negative impact on mood and energy, and a higher risk of developing osteoporosis.

Patients who have other underlying health conditions may find that prescription pain medications increase overall risks of complications and unwanted side effects. The legalization of medical cannabis in most states across America provides what many believe to be a safer alternative to prescription drugs for pain.

How Cannabinoids Work Together to Provide Relief

The entourage effects of cannabis are still being studied, and there are many things the medical community does not understand about the interaction between different cannabinoids and potential therapeutic benefits. But they do know that there is more to the effects of cannabis for pain relief than just the two major cannabinoids, THC and CBD.

Cannabigerol (CBG)

This minor cannabinoid is often discussed for its potential pain-relieving properties. Not only does Cannabigerol function as a mild analgesic, but it can also help reduce inflammation. The CBG cannabinoid engages both CB1 and CB2 receptors.

Cannabichromene (CBC)

This non-psychoactive minor cannabinoid has known analgesic or pain-relieving effects. While it does not bind directly to CB1 receptors in the human body, it does with other types of receptors in the endocannabinoid system.

Cannabidivarin (CBDV)

Anti-convulsant medications are often prescribed for pain relief, and CBDV has the same potential. If prescription anti-convulsants work, so too could CBDV, which is also a powerful anti-inflammatory that can reduce pain perception and discomfort.

Cannabinol (CBN)

Cannabinol or CBN does not produce psychoactive effects or impairment, but it may provide mild analgesic or pain-relieving effects. The metabolite cannabinoid is naturally formed when cannabis ages and THC turns into CBN when exposed to UV light for long periods of time.

When choosing cannabis products for pain relief, look for strains that have more than THC and CBD content. You may find that minor cannabinoids like cannabichromene (CBC), and cannabidivarin (CBDV) may help you achieve your pain management goals.

Potential Side Effects of Cannabis in Pain Management

We know that THC activates cannabinoid receptors in the body, and there is some scientific evidence that it can provide symptom relief, not just for chronic pain but for muscle spasms and mental health symptoms as well. Are there any side effects of marijuana that patients should be aware of?

Like any drug, healthcare professionals warn that there has not been enough research about the long-term use of cannabis to fully understand what impact it can have, particularly when used regularly for years. Some studies conducted cognitive tests that revealed minimal impact on the prefrontal cortex and brain development when used responsibly.

However, that is not to imply that there are no potential side effects on the human brain. Adolescent cannabis users may experience problems with cognitive impairment if chronic cannabis use occurs before the age of twenty-one years. The effects on a developing brain can lead to poorer cognitive performance, changes in emotional behavior, and changes to healthy brain structure.

For adults who use cannabis on a daily basis, there may also be increased coronary artery risk development, impact on emotional regulation, and other negative health effects. Many of the studies that warn about cannabis use refer to smokable cannabis and inhalable products, and more research is needed to understand the impact on vascular biology and marijuana’s effect on the brain.

How to Use Cannabis Responsibly for Pain

When cannabis is used for medical purposes, patients benefit from the guidance of an experienced healthcare provider. Because higher potency cannabis products can lead to developing a cannabinoid tolerance, ask health care professionals about suggested THC potencies that may be effective. The lowest potency that manages your symptoms is the best place to start.

Consider that cannabis is only one part of an effective treatment plan for chronic pain management. Exercise, dietary changes, mental health support, and other therapies can help you reduce the severity of pain symptoms you experience.

Dr. Marissa Magsino

With over 25 years of specialty training in Internal Medicine, as well as fellowship training in Functional and Sexual medicine, Dr. Maginso added Plant Medicine (Medical Marijuana) to her niche practice as of 2017. She is licensed in the State of Florida and attended the University of the East (UERM) in Quezon City, Philippines as well as the University of Medicine and Dentistry in Newark, NJ.

She joined DocMJ in 2019 to align with a known group of compassionate physicians that empower their patients to be better versions of themselves. Her favorite hashtag is #powerpassionperformance, using the combination of optimized bioidentical hormones, medical marijuana, plasma therapies, and sexual wellness.

She is an author, speaker and community advocate for Medical Marijuana, Sexual Health, and the empowerment of mature women.