Can you get medical cannabis for complex regional pain syndrome in the UK?

Complex regional pain syndrome is rare, severe, and badly served by the treatments available. Pain is out of proportion to the original injury, and the standard options — physiotherapy, neuropathic pain medicines, nerve blocks — often fall short. That is the setting in which UK specialists consider a cannabis-based medicine, on the thinnest evidence base on this site.

Is complex regional pain syndrome treated with medical cannabis in the UK?

It is considered, individually, and almost always in people who have already been through specialist pain services without adequate relief. It is not an NHS treatment for CRPS and no product is licensed for it.

CRPS usually follows an injury or surgery and produces burning pain, swelling, changes in skin colour and temperature, sensitivity to light touch, and loss of function in the affected limb. UK practice, set out in Royal College of Physicians guidance, is built around early multidisciplinary care: physical rehabilitation, pain management, and psychological support together, with medicines playing a supporting role rather than a leading one.

A specialist considering a cannabis-based medicine for CRPS is looking for something that makes rehabilitation possible — not something that replaces it. If pain relief comes at the cost of engagement with physiotherapy, it has not helped.

What the evidence actually shows

This is the weakest evidence base on this site. There is no randomised controlled trial of cannabis-based medicines in complex regional pain syndrome. What exists is a small UK case series and indirect evidence borrowed from the neuropathic pain literature.

Researchers analysing the UK Medical Cannabis Registry published a clinical outcomes analysis for CRPS patients, tracking patient-reported pain, sleep, anxiety and quality-of-life measures over six months. It reported improvements across those measures with adverse events that were mostly mild or moderate. As a case series with no control group, it cannot distinguish the medicine from the natural course of the condition, from regression to the mean in people who enrolled at their worst, or from the effect of expectation. The authors say as much.

Anyone telling you the evidence for CRPS is strong is not describing the literature.

What a specialist will want to see

There is no UK list of qualifying conditions, so nothing here entitles you to a prescription. A specialist works through your history and decides whether a monitored trial is justified for you. For complex regional pain syndrome they will typically look at:

• Whether CRPS has been formally diagnosed, and against which criteria
• Whether you have been seen by a specialist pain service and what that involved
• Which neuropathic pain medicines you have tried — and nerve blocks or other interventions, if offered
• How you are getting on with physical rehabilitation, and what is stopping you
• The psychological impact, which in CRPS is substantial and is treated as part of the condition, not a side issue
• Your other medicines, and your personal and family history of psychosis

The general requirements — age, a documented diagnosis, the convention that two standard treatments have been tried, and access to your medical records — are covered in What are the requirements?

Risks and reasons a specialist may say no

With evidence this thin, the main risk is a mismatch between hope and outcome. CRPS is a condition where people have often been let down repeatedly, and a specialist who promises a result rather than a trial is not being straight with you.

The pharmacological risks are the usual ones: drowsiness, dizziness, impaired concentration, dry mouth and driving impairment from THC-containing products. Sedation matters more than usual here, because anything that reduces your capacity for physical rehabilitation works against the treatment that has the best evidence behind it. Personal or family history of psychosis, unstable mental illness, pregnancy and breastfeeding all count against treatment.

If you want to take this further

The useful next step is a proper assessment, not a better list. Gather your diagnosis, the treatments you have already tried and what happened with each, and your current medicines — that is what a specialist needs in order to give you a straight answer.

The consultation itself, and what happens after it, is set out in What is the process to get a medical cannabis prescription? If complex regional pain syndrome is not the only thing you are being treated for, say so early: other conditions and other medicines change the assessment.

Patient guide · Written by the Flora House editorial team · Last reviewed: 31 August 2026