Medical cannabis for inflammation: evidence, treatment options, and safety (Updated)

What is inflammation, why does it occur, and can medical cannabis help?

The term inflammation refers to when the body releases a cascade of biochemical signals that increase blood flow to an affected area and activate immune cells. This acute inflammation is vital to healing and repair, but can also contribute to the heat, swelling, and discomfort that so often accompany injury or illness. 

These reactions are clear signs that the immune system is doing its intended job, but not all inflammation is part of a normal and healthy functioning system. When the issue is resolved, be it injury or illness, the process shifts from short-term protection to long-term disruption.

Chronic inflammation explained

Chronic inflammation (sometimes also referred to as ‘slow, long-term inflammation’) is when the inflammatory response lasts for months, even years. It is linked with ongoing pain, fatigue, mobility issues, GI illnesses, along with so many other chronic health concerns. 

In certain cases, the immune system continues to respond to try to fight a disease that has already been taken care of, or even misidentifies our own healthy system as a threat that needs to be handled. 

This is the type of inflammation seen in conditions that medical cannabis can be prescribed for like arthritis, psoriasis, inflammatory bowel disease, and a range of autoimmune issues where the immune response becomes far more persistent than it needs to be. The symptoms may ebb and flow, but the underlying inflammatory drive is still there, shaping how the body feels and functions day to day.

So, where does medical cannabis for inflammation enter the equation?

Long heralded for its ability to potentially help the body reduce the impact of a range of inflammation issues, cannabis has played a somewhat surprising role throughout world history as a medicinal relief option for inflammation, but it is only recently that the plant has been able to be legally and thoroughly studied.

How does the endocannabinoid system influence inflammation?

The endocannabinoid system (ECS) is a vast, interconnected network of signalling chemicals and receptors spread throughout the body. Only discovered in 1988, the ECS plays a heavy hand in regulating many of our most essential bodily functions, including learning and memory, emotional processing, sleep, temperature control, pain control, immune and inflammatory responses, and appetite.

It is made up of three core ‘components’:

• Cannabinoid receptors: CB1 receptors are found mostly in the central nervous system, with CB2 receptors being far more common in the peripheral nervous system. This split is important, with CB2 receptors being more closely tied to immune system functioning and the inflammatory response.
• Endocannabinoids: These are the ECS signalling molecules our bodies naturally produce, which bind with both CB1 and CB2 receptors and regulate how active the ECS is.
• Metabolic enzymes: Once our endocannabinoids have carried out their role, enzymes break them down to make sure the ECS can continue functioning properly. 

Now, you may have noticed the term ‘cannabinoid’ being very much present here. The ECS is named as such because researchers only discovered it while trying to understand how the body responds to THC (one of the two major cannabinoids produced by cannabis plants). 

The compounds produced by Cannabis sativa L. genus led scientists to discover the largest neurotransmitter system in our bodies, not the other way around. 

The cannabinoids (or phytocannabinoids, to be more precise - THC and CBD, along with other minor cannabinoids) offered up by cannabis have a remarkably similar chemical structure to our own endocannabinoids, and as such, can bind with the ECS receptors, along with other signalling pathways that sit alongside them.

The role of CB1 and CB2 receptors in inflammation

While CB1 receptors sit mostly in the brain and spinal cord, they do not play a huge role in how our bodies generally generate inflammation itself, with one important caveat… 

Neurological inflammation, which can occur in conditions such as multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, traumatic brain injury, and certain chronic pain disorders, involves inflammatory activity within the central nervous system itself. In these settings, shifts in CB1 activity can affect how the nervous system responds to ongoing stress or injury. 

CB2 receptors are more important to the overall inflammatory response. Found on the surface of many immune cells, they play a role in which immune responses are triggered, how strongly these cells react to the stimuli, and which inflammatory signals are sent to help the affected area. This means that CB2 activation is very much front and centre when it comes to research on how cannabinoids may influence immune activity and the broader inflammatory process.

How do cannabinoids (THC and CBD) influence the body’s ECS and inflammatory response?

A recent comprehensive review of cannabis and its impact on the immune response (published in November 2025) clearly shows how differently THC and CBD behave in terms of the inflammatory response, and how each one can influence inflammatory signals through separate, sometimes overlapping pathways. The review included 236 previous research papers from January 2000 through February 2025, making it the largest review of its kind to date. 

Of the two, THC has a much more direct effect on the ECS. It binds strongly with CB1 receptors (and to a lesser extent, CB2 receptors), which means THC can influence how pain signals are perceived, and how strongly certain immune responses are triggered. This may reduce the release of some inflammatory messengers, although this effect is individualised and also depends on dose and the condition being treated. 

CBD doesn’t interact with the ECS in the same direct way as THC. While it only binds in a weak fashion to CB2 receptors, and barely at all to CB1, it does slow the breakdown of our own endocannabinoids. This means the body’s natural ECS signals stay active for longer, which can influence how inflammatory messages are handled.

Here’s a brief breakdown of the currently available evidence for both THC and CBD when it comes to their impact on the inflammatory response.

 How THC interacts with inflammation

How CBD interacts with inflammation

How cannabinoids may influence key inflammatory pathways

Above, we have gone over how cannabinoids (THC and CBD) interact with not just the ECS, but also several of the receptor and signalling pathways that sit alongside it.

• Cytokines are the molecules that immune cells use to communicate. Some of the preclinical studies included in the 2025 review showed that both THC and CBD may reduce some of the pro-inflammatory cytokines, including IL-1β, TNF-α and IL-6. 

• Oxidative stress is another of the main drivers behind chronic inflammation, especially in conditions where tissues are repeatedly damaged or inflamed (such as rheumatoid arthritis, inflammatory bowel disease, psoriasis, and certain neurodegenerative disorders like Alzheimer’s and Parkinson’s). CBD shows the most promise here and seems to push oxidative stress markers down by interacting with pathways like TRPV1 and PPAR that sit close to the ECS (quite dramatically in some of the research).    

How do different medical cannabis products fit into inflammation management?

In this brave new world of UK medical cannabis legality, the range of treatment options available to patients looking for a natural complementary/alternative to pharmaceuticals is ever-growing. 

Keep in mind, the level of regulatory oversight for medical cannabis in the UK is among the most stringent worldwide. When you become a Releaf patient, you have access to everything that has made us the most trusted medical cannabis clinic in the UK, but also a wide range of medications that meet strict manufacturing and prescription requirements. 

Never self-medicate with black market cannabis. Cannabis products sourced on the street have zero regulatory oversight and can contain harmful byproducts.

What should patients know about medical cannabis safety and interactions?

In the overwhelming majority of trials involving human participants taking medical cannabis, the treatment is generally very well tolerated. The full Releaf sign-up process (and beyond) is conducted with patient safety as the number one priority. 

During your first appointment, one of the GMC-registered specialists who make up Releaf’s world-class clinical team will take their time to fully understand your condition and symptoms, the treatments you have tried so far, and any medications or conditions that could have an impact on your response to THC and/or CBD treatment. 

All Releaf patients are required to attend regular follow-up appointments to ensure that their treatment plan is not only as effective as possible, but also fully safe. When you first sign up as a Releaf patient and pay for your first prescription, you will be mailed a free UK medical cannabis card, which makes identifying yourself as a fully legal and compliant patient extremely easy.

FAQs on medical cannabis for inflammation

Can medical cannabis reduce inflammation?

Yes, the latest research shows that both THC and CBD can help reduce inflammation, along with the pain and mental strain that chronic conditions cause. Medical cannabis is not a cure, but it may reduce the impact of chronic inflammation and help patients manage symptoms linked with inflammation under specialist guidance.

Does THC or CBD work better for inflammatory symptoms?

Both THC and CBD have been shown to help reduce inflammation, but in different ways. THC interacts more directly with CB1 and CB2 receptors, which can influence both pain and immune signalling. CBD takes a gentler approach, slowing the breakdown of our own endocannabinoids and interacting with pathways linked to inflammation and oxidative stress.

Is medical cannabis suitable for chronic inflammation for UK patients?

Yes, as long as you have tried at least two ‘conventional’ treatment options with little or no relief. Suitability depends on a range of factors, including medical history and your current diagnosis. To find out more, head to Releaf’s medical cannabis eligibility checker.

How long might it take to notice a reduction in inflammation when taking medical cannabis?

That depends on a huge range of factors. Medical cannabis treatment is individualised, meaning what works for one patient may not for another (or it may). It also depends on what form of medical cannabis is prescribed, the dose, and 

How can you access medical cannabis for inflammation in the UK?

The easiest first step for UK residents looking to begin medical cannabis treatment is Releaf’s medical cannabis eligibility checker, a fast and free tool that takes all of 20 seconds to complete and helps you understand whether medical cannabis may be suitable for your health history and current needs.

If so, you will be prompted to: 

• Create a Releaf account
• Upload your medical documentation
• Book in for your initial consultation

What are you waiting for? Head to our medical cannabis eligibility checker right now to find out if a UK medical cannabis prescription may be right for you. It is free and gives you an instant answer on whether you may be potentially eligible for a Releaf treatment plan.