Find the Right Cannabis for Pain Relief in the UK

The UK allows prescription of cannabis products for pain when other treatment options have failed. 

But what products are most helpful for pain relief? For many patients, it's easy to feel overwhelmed when discussing options with a specialist. 

To help patients have a more informed conversation with their physician about treatment options, we look at how cannabis interacts with pain, how the evaluation process works, and how cannabis products differ.

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How Does Cannabis Work as a Painkiller?

Cannabis produces over 100 compounds called cannabinoids, with tetrahydrocannabinol (THC) and cannabidiol (CBD) being the most studied. These compounds interact with the body’s endocannabinoid system (ECS). This system regulates pain, inflammation, and other processes.

THC binds to receptors in your endocannabinoid system, which may help reduce pain signals, including nerve pain, and reduce muscle spasms. 

Unlike THC, CBD doesn’t cause intoxication. Instead, it may potentially reduce inflammation and calm overactive pain pathways. This may help relieve certain symptoms of chronic pain or arthritis.

Studies show cannabis may help with neuropathic pain, arthritis, and pain linked to multiple sclerosis (MS). For example, some patients with MS report significant pain relief and improved quality of life after using cannabis. Others, like cancer patients, find it helps manage pain when traditional treatments fall short.

There’s also evidence that cannabis can reduce reliance on opioids. Some chronic pain patients who use cannabis cut their opioid use significantly, often with fewer side effects and a greater sense of control over their pain.

Of course, cannabis isn’t a one-size-fits-all treatment. Specialists consider pain type, body chemistry, medication interactions and more when deciding on strain, dosage, and delivery method. That’s why every cannabis patient must work closely with their physician when beginning cannabis treatment.

Can You Get Medical Cannabis for Pain in the UK?

Yes, medical cannabis is legal in the UK for certain conditions, including chronic pain, fibromyalgia, and neuropathic pain. However, it’s only available through a specialist prescription, and accessing it through the NHS is difficult. 

Since November 2018, specialist doctors have been allowed to prescribe cannabis-based products for medicinal use (CBPMs), but only when other treatments haven’t worked. For many people, the most practical treatment route is through a private clinic.

Most physicians won't consider cannabis treatment for pain unless the patient meets the following criteria:

1. The patient has a serious chronic condition that hasn’t improved with conventional treatments. 
2. The patient has tried several other treatment options without finding relief. 
3. The specialist physician believes that cannabis may be appropriate and the potential benefits of treatment reasonably outweigh the potential risks.

Conditions like chronic pain, fibromyalgia, and neuropathic pain may qualify for medical cannabis in the UK.

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Can Cannabis Interact with Pain Medications?

If you’re already taking pain medications, it’s important to know how cannabis may affect them. CBD, for example, can change how your body processes certain drugs.

CBD slows down liver enzymes like CYP2D6 and CYP3A4, which break down many medications. This can make drugs like opioids, antidepressants, or anti-inflammatories stronger or cause unexpected side effects.

Here’s what to watch out for:

• Opioids: CBD may make them more potent, increasing the risk of drowsiness or breathing problems.¹
• Anti-inflammatories: Mixing CBD with drugs like naproxen or celecoxib could raise their levels in your bloodstream.¹
• Antidepressants: CBD can increase the concentration of SSRIs, tricyclic antidepressants, and MAOIs, potentially leading to side effects like drowsiness or heart rhythm issues.¹
• Over-the-counter meds: Even common pain relievers like ibuprofen or paracetamol could interact with CBD, though research is still limited.

Herbal remedies can also interact with cannabis. For example:

• St. John’s Wort, often used for pain and mood, may amplify CBD’s effects.
• Kava, used for anxiety and pain, could increase the risk of liver-related side effects.

To stay safe, tell your doctor about every medication, supplement, or herb you’re using, including over-the-counter products. They can help you avoid harmful interactions and ensure your treatment plan works for you.

Should You Choose Flower or Oils?

If you’re considering cannabis for pain relief, your specialist will need to decide between different forms, like flower and oils. In the UK, smoking cannabis isn’t allowed for medical use, but vaping is an option.

• Cannabis Flower: Vaping dried flower lets cannabinoids absorb quickly, which may be able to provide fast relief. However, you’ll need a vaporiser, which isn’t as discreet as other methods.
• Oils and Tinctures: These are taken under the tongue (sublingually) and provide longer-lasting effects. They’re easy to dose and a good choice if you’d rather not inhale.

Your prescribing specialist will work with you to find the best option for your condition and lifestyle. 

Choosing Cannabis Flower: Strains, Terpenes, and Cannabinoids

Cannabis flower isn’t one-size-fits-all. The effects you feel depend on the strains, terpenes, and cannabinoids in the product. Here’s what you need to know:

• Strains: Cannabis strains can vary widely in their effects. Some are more calming, while others may feel more energising. Your specialist can help you pick one that fits your pain and lifestyle.
• Terpenes: These natural compounds give cannabis its smell and flavor. They also influence how it affects you. For example, myrcene is often linked to relaxation, while limonene may help with inflammation.
• Cannabinoids: The two main cannabinoids are THC and CBD. A product with a mix of both may offer pain relief without excessive intoxication.

How to Find the Right Products at Your Pharmacy

Once you’re prescribed medical cannabis, your pharmacy and prescribing specialist will help you find the right products. This process is a team effort. You’ll discuss your medical history, medications, and pain symptoms to determine what works best for you.

Here are some questions to ask:

• What strains or products are best for my type of pain? 
• How should I dose this product? 
• Are there any potential interactions with my current medications? 
• What’s the best way to consume this product?

If your current product isn’t working or you’d like to try something different, book a follow-up consultation. Your specialist can adjust your treatment plan to better suit your needs.

Is Cannabis or CBD Better for Pain?

Studies show THC may reduce pain signals, while CBD is often researched for its anti-inflammatory effects. A mix of both may work best, but more research is needed.

Is Medical Cannabis Legal in the UK?

Yes, medical cannabis is legal in the UK, but it’s only available through a specialist prescription. Recreational use is illegal.

What Cannabis Product Is Best for Joint Pain?

For joint pain, many people try CBD oils or topicals, which target the area directly. Because cannabis works differently for everyone, it’s best to talk to a doctor about what may work for you.

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1. Balachandran P, Elsohly M, Hill KP. Cannabidiol Interactions with Medications, Illicit Substances, and Alcohol: a Comprehensive Review. J Gen Intern Med. 2021;36(7):2074-2084. doi:10.1007/s11606-020-06504-8. ↩︎

The information in this article and any included images or charts are for educational purposes only. This information is neither a substitute for, nor does it replace, professional legal advice or medical advice, diagnosis, or treatment. If you have any concerns or questions about laws, regulations, or your health, you should always consult with an attorney, physician or other licensed professional.