Medical Cannabis vs. Other Pain Relief: What You Need to Know

Chronic pain is a complex beast. Many sufferers cycle through multiple treatments, often with limited success and unwanted side effects. Lately, medical cannabis is getting attention as an alternative or adjunct option. But how does it stack up against conventional pain relief? In the UK context, what’s legal, what works, and what risks do you face? Below we will walk you through:

• How medical cannabis works (and its legal status in the UK)
• Mainstream pain relief options (from simple to advanced)
• Pros, cons, and trade-offs
• Practical guidance and red flags

What is medical cannabis (or cannabis-based medicinal products, CBPMs)?

“Medical cannabis” is shorthand for cannabis-derived or cannabis-based medicinal products (CBPMs) that are used under medical supervision, not for recreational use.

In the UK:

• Since November 2018, cannabis for medicinal use has been legal in limited circumstances (i.e. as a prescription by specialist doctors).
• However, this does not mean it is freely available. Access is tightly controlled: only hospital specialists (or doctors on the specialist register) may initiate prescriptions.
• Where possible, licensed cannabis-derived medications (or formulations) are preferred over “unlicensed specials”.
• One such product is nabiximols (brand name Sativex), a THC/CBD oromucosal spray licensed in the UK for spasticity in multiple sclerosis.

NICE (the National Institute for Health & Care Excellence) has a guideline (NG144) on cannabis-based medicinal products, including their use in chronic pain, but is cautious in its recommendations. The British Pain Society similarly does not recommend CBPMs for routine chronic pain use due to limited evidence.

In short: medical cannabis is legally possible in the UK under narrow conditions, but it is not a “first line” option for most pain sufferers.

How does medical cannabis (cannabinoids) produce pain relief?

The active compounds in cannabis that draw interest are mainly THC (tetrahydrocannabinol) and CBD (cannabidiol). Here’s a simplified breakdown of mechanisms and theories:

• The human body has an endocannabinoid system (ECS), with cannabinoid receptors (CB1, CB2) that modulate pain signalling, inflammation, and other physiological responses.
• THC binds more directly to CB1/CB2 and has psychoactive effects; CBD influences the system more indirectly (e.g. modulating receptor activity, reducing inflammation).
• Some believe in an “entourage effect”, that the mix of compounds in whole-plant cannabis (minor cannabinoids, terpenes) produces more balanced effects than pure isolates.
• In pain, cannabinoids may reduce nerve excitability, reduce central sensitisation, modulate inflammatory mediators, or dampen pain signal transmission.

Clinical data is still emerging. Some studies report benefit, especially for neuropathic pain, but effect sizes and consistency are modest.

A 2024 review in BMJ Open comparing medical cannabis vs opioids for non-cancer chronic pain found mixed evidence: cannabis may offer modest relief with fewer risks of overdose but also carries its own side effects and uncertainties.

Conventional pain relief options: the landscape

Before considering medical cannabis, most patients will try a sequence of more standard analgesic approaches. Below is a hierarchy of options, roughly from mild to strong, with pros, cons, and things to watch out for.

Option	Examples / Classes	Mechanism / Notes	Pros	Risks & Drawbacks	Suitability
Over-the-counter (OTC) analgesics	Paracetamol (acetaminophen), NSAIDs (ibuprofen, naproxen), topical gels/creams	Reduce pain and inflammation peripherally	Cheap, easy access	Gastrointestinal issues, liver toxicity (paracetamol), kidney problems, cardiovascular risk (NSAIDs)	Mild to moderate pain, flare ups
Simple adjuvants	Topical capsaicin, heat/cold therapy, TENS, physical therapy, exercises, massage, acupuncture	Local modulation, gate control theory, improved mobility	Low systemic risk, can complement drugs	Variable efficacy, requires compliance/time	Musculoskeletal, neuropathic adjuncts
Weak opioids / mild prescription analgesics	Codeine combinations, tramadol	Act centrally on opioid receptors	More potent pain relief than OTCs	Nausea, constipation, tolerance, dependency risk	Moderate pain not responding to OTCs
Strong opioids / controlled meds	Morphine, oxycodone, fentanyl, methadone	Powerful central pain suppression	Effective in acute severe pain, cancer pain	High risk: tolerance, addiction, respiratory depression, overdose	Severe pain, palliative care, cancer pain
Adjuvant neuropathic / non-analgesic meds	Antidepressants (amitriptyline, duloxetine), anticonvulsants (gabapentin, pregabalin), muscle relaxants, NMDA antagonists	Modulate nerve sensitisation, descending pain pathways	Especially helpful in neuropathic pain	Side effects: drowsiness, weight gain, dizziness, interactions	Neuropathic pain, fibromyalgia, shooting/nerve pain
Interventional / procedural therapies	Nerve blocks, radiofrequency ablation, spinal cord stimulation, epidural injections, surgery	Target pain sources directly	Can provide long term relief for selected patients	Invasive risks, cost, failure rates	When medication alone is insufficient
Complementary / lifestyle & integrative	Mindfulness, CBT, diet, sleep hygiene, weight loss, exercise, cognitive therapies	Address the biopsychosocial dimension of pain	Low harm, can boost overall outcomes	Requires effort, variable response	Chronic pain with psychological components

 
In reality, best practice is often multimodal, combining pharmacological, interventional, rehabilitation, and psychological strategies.

Medical cannabis vs conventional pain relief: comparison & trade-offs

Here’s what you should weigh if you or your clinician are considering cannabis as part of the regimen.

Advantages / potential benefits of medical cannabis

1. Different mechanism: May help when traditional analgesics fail or are contraindicated (e.g. opioid side effects).
2. Reduced opioid burden: Some observational data suggest people using cannabis reduce their opioid usage over time.
3. Lower overdose risk (vs opioids): While cannabis has its risks, fatal overdose risk is negligible compared to opioids.
4. Additional symptomatic benefits: In some patients, improvement in sleep, mood or spasticity are seen.
5. Possibility of targeted dosing / delivery: Oils, sprays, and inhaled forms allow flexibility.

When might medical cannabis be considered (in the UK)?

Here’s a rough pathway by which medical cannabis could be considered:

1. Exhaust standard therapies
   You’ve tried (or been trialled on) safer analgesics, adjuvants, interventional procedures, rehab, psychological support, etc., with incomplete pain control or intolerable side effects.
2. Referral to specialist
   A hospital consultant (pain specialist, neurology, rehabilitation) who is on the GMC specialist register must consider prescribing. General GPs cannot initiate.
3. Risk/benefit assessment
   Consider history of psychiatric illness, risk of substance misuse, interactions, and comorbidities.
4. Start with a licensed / better-evidenced product
   Where applicable, start with products that have more regulatory backing (e.g. Sativex) before moving to unlicensed “specials”.
5. Trial period & monitoring
   Use a defined trial period (e.g. 4–12 weeks), and monitor pain scales, side effects, and functionality. Continue only if benefit outweighs harm.
6. Long-term oversight
   Regular reviews, mental health assessments, checking for tolerance, adjusting other medications, and a plan for de-escalation if ineffective.

Tips for patients / pain sufferers (do’s & don’ts)

Don’t push your GP for medical cannabis as a first option; most aren’t able to prescribe it.

Be prepared to provide a detailed pain history, previous treatments, comorbid conditions, and psychiatric history.

If a private clinic offers you “guaranteed medical cannabis for pain” without exploring alternatives, be wary.

• Ask about drug interactions with your current medications.
• Don’t expect immediate dramatic relief; set realistic expectations.
• Keep logs: pain levels, side effects, functional changes.
• Always have a fallback plan (e.g. rescue analgesic) if cannabis is ineffective or causes side effects.
• Engage in non-drug therapies (physio, CBT, exercise) cannabis is rarely enough alone.

Conclusion

Medical cannabis is not a magic bullet. In the UK, it is legally available only in narrow circumstances and is not recommended for routine chronic pain use given the limited evidence base. The bulk of pain management for most patients will continue to rely on a layered approach, from OTC analgesics, adjuvant therapies, and physical/psychological interventions to more powerful prescription or interventional methods.

However, for a small subset of patients who have failed multiple lines of treatment and in whom a specialist deems it appropriate, CBPMs may offer additional benefit. If you’re exploring this path, go in with your eyes open: demand rigorous monitoring, insist on transparency regarding side effects, and never neglect the non-drug pillars of good pain care.