Dr Simon Erridge, Head of Research, Curaleaf Clinic, reflects on some of the key findings published from the UK Medical Cannabis Patient Registry this year.
As we look back on 2025, it’s been another year of deepening understanding about how medical cannabis is being used in the UK. Research from Curaleaf Clinic’s UK Medical Cannabis Registry, the largest of its kind, alongside other studies, has offered valuable insight into patient experiences across a wide range of conditions.
Our work is guided by a simple principle: improving patient care. By analysing patterns in symptoms, tolerability, and treatment approaches, we aim to generate insights that support clinicians and help patients make informed decisions.
This year, 15 new peer-reviewed studies added further detail to how patients respond to treatment in real-world settings. Here are some of the key things we’ve learned.
Longer-term data is becoming available
One of the most significant developments this year has been the publication of longer follow-up studies. Previous research often looked at patients for just three or six months, but new studies have now tracked patients for 18 to 24 months. This longer-term perspective helps us better understand how people’s experiences may change over time.
Emotional burden of endometriosis
Endometriosis affects 6-10% of women of reproductive age and can cause significant pelvic pain. Our review examined all available studies in this field, including surveys of people who use cannabis for endometriosis symptoms. Importantly, the research identified that high-quality clinical trials are still needed in this area. This was reinforced by a UK Medical Cannabis Registry study assessing the outcomes of patients in the UK, outlining changes in the affective dimension of their pain, alongside physical symptoms.
Insomnia and age-related responsiveness
Insomnia affects millions of people in the UK, and many have tried multiple licensed medications before considering medical cannabis. Interestingly, patients over 50 with insomnia were more likely to experience clinically meaningful changes in sleep quality compared with younger cohorts, potentially due to age-related differences in cannabinoid metabolism or sleep architecture. These patterns indicate that age may play a meaningful role in treatment response and should be considered in prescribing decisions.
Cannabis product safety in the illicit market remains a serious concern
Perhaps one of the most sobering findings this year came from an analysis of illegal cannabis products submitted for testing to the WEDINOS drug checking service. The research found that over one-third of samples contained psychoactive adulterants, with synthetic cannabinoids being the most common. Vape products showed particularly high contamination rates. This research highlights the potential dangers of unregulated cannabis and underscores why quality-controlled, pharmacy-dispensed products are important for those using cannabis for medical purposes.
Post-traumatic stress disorder research has been updated
PTSD can be a challenging condition to manage, and our study following patients for up to 18 months looked at how patients’ symptoms, sleep quality, and anxiety levels changed over time. This research also found differences in response between males and females, adding to emerging evidence that sex may influence therapeutic response.
Multiple sclerosis outcomes
MS can cause a wide range of symptoms, including pain, spasticity, sleep problems, and anxiety. An updated analysis, tracking people for up to 24 months, looked at MS-specific quality of life measures as well as general well-being. With over 2.8 million people living with MS worldwide, understanding all treatment options available is important for patient care.
Complex Regional Pain Syndrome (CRPS)
The first dedicated real-world evidence for cannabis-based medicines in CRPS, a chronic pain condition that is relatively rare and difficult to treat. These findings may offer clinicians an additional option for a condition that often responds poorly to standard treatments.
Substance use disorder and harm reduction
For the first time, we published an analysis of patients treated for substance use disorder. This included people with opioid use disorder, alcohol use disorder, and other substance use conditions. This limited study provided evidence towards a harm reduction role for medical cannabis in individuals with previous substance misuse.
Epilepsy research provides new insights
About one-third of people with epilepsy don’t achieve adequate seizure control with licensed anti-seizure medications. Patients aged 55 and over were more than eight times more likely to achieve meaningful changes in epilepsy-specific quality of life, suggesting that older adults with treatment-resistant epilepsy may respond differently to younger adults, potentially reflecting different responses according to the causes of epilepsy.
Hypermobility-associated chronic pain is gaining attention
2025 saw the examination of cannabis-based medicinal products in patients with hypermobility spectrum disorder (HSD) and hypermobile Ehlers-Danlos Syndrome (hEDS). These connective tissue conditions can cause chronic pain that’s often difficult to manage with conventional treatments. The research tracked patients for up to 18 months, showing sustained changes in pain levels and health-related quality of life.
Cancer pain remains an important area of focus
New research has examined how patients with cancer-related pain reported their experiences when prescribed cannabis-based medicinal products. Cancer pain can be complex and often requires multiple approaches to management. The study looked at pain intensity, sleep quality, and overall quality of life.
Misinformation online is a growing concern
A systematic review examining medical cannabis content on YouTube has highlighted concerns about the quality of information available online. The research found that whilst YouTube is a major source of health information for many people, the platform’s algorithms may prioritise engagement over accuracy. This study emphasises the importance of seeking information from reliable, evidence-based sources and discussing treatment options with qualified healthcare professionals.
Looking Ahead: 2026 and Beyond
These studies provide valuable insights into medical cannabis use in the UK. Real-world evidence from registries like the UK Medical Cannabis Registry helps bridge the current evidence gap by showing how cannabis is used in routine clinical practice and what patients experience. However, randomised controlled trials remain essential to improve access beyond private clinics.
There are encouraging signs of international progress. In 2025, two major clinical trials across Europe examined medical cannabis for chronic low back pain. These studies mark significant advances and demonstrate that high-quality research in this area is both possible and necessary.
While the UK has the infrastructure to lead in this field, it urgently needs its own programme of rigorous clinical trials. Currently, medical cannabis is only available to patients who have not found adequate relief from licensed medications. To expand NHS access beyond a “treatment of last resort,” robust evidence is required to guide NHS and NICE decisions about which patients might benefit and under what circumstances.
What this body of research does show is that medical cannabis is being increasingly prescribed for a diverse range of conditions, typically when people have not found adequate relief from licensed medications. The studies also demonstrate that researchers are carefully monitoring patient experiences, including both reported benefits and side effects. Importantly, it also shows that patients in the UK are committed to contributing to research around medical cannabis. It is through their efforts that we have been able to make strides in understanding to date, so thank you to all those who have given their time to contribute to research and will continue to do so in 2026 and beyond.
References:
Getter S, Erridge S, Warner-Ley J, Clarke E, McLachlan K, Coomber R, Barnes S, Darweish Medniuk A, Guru R, Holden W, Sajad M, Searle R, Usmani A, Varma S, Rucker JJ, Platt M, Sodergren MH. A Longitudinal Assessment of Endometriosis Patients Prescribed Cannabis-Based Medicinal Products: A Case Series from the UK Medical Cannabis Registry. The Australian and New Zealand Journal of Obstetrics and Gynaecology. 2025. doi: http://doi.org/10.1111/ajo.70078
Aggarwal A, Erridge S, Cowley I, Evans L, Varadpande M, Clarke E, McLachlan K, Coomber R, Rucker JJ, Weatherall MW, Sodergren MH. UK Medical Cannabis Registry: A Clinical Outcomes Analysis for Insomnia. PLOS Mental Health. 2025. doi: https://doi.org/10.1371/journal.pmen.0000390
Erridge S, Sodergren MH. Medical Cannabis and Insomnia: A Narrative Review. Expert Review of Neurotherapeutics. 2025. doi: https://doi.org/10.12968/bjnn.2024.0011
Varadpande M, Erridge S, Aggarwal A, Cowley I, Evans L, Clarke E, McLachlan K, Coomber R, Rucker JJ, Platt MW, Khan S, Sodergren MH. UK Medical Cannabis Registry: An Analysis of Clinical Outcomes of Medicinal Cannabis Therapy for Cancer Pain. Journal of Pain and Palliative Care Pharmacotherapy. 2025. doi: https://doi.org/10.1080/15360288.2025.2457101
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Datta A, Erridge S, Warner-Levy J, Clarke E, McLachlan K, Coomber R, Asghar M, Bhoskar U, Crews M, De Angelis A, Imran M, Kamal F, Korb L, Mwimba G, Sachdeva-Mohan S, Shaya G, Rucker JJ, Sodergren MH. UK Medical Cannabis Registry: An updated clinical outcomes analysis of patients with post-traumatic stress disorder. Expert Review of Neurotherapeutics. 2025. doi: https://doi.org/10.1080/14737175.2025.2490539
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Ghosh A, Erridge S, Coomber R, Bhoskar U, Holden W, Kamal F, Mwimba G, Sachdeva-Mohan S, Shaya G, Usmani A, Rucker JJ, Sodergren MH. UK Medical Cannabis Registry: A Clinical Analysis of Patients with Substance Use Disorder. European Addiction Research. 2025. doi: https://doi.org/10.1159/000547696
Cowley I, Erridge S, Aggarwal A, Evans L, Varadpande M, Clarke E, McLachlan K, Coomber R, Iqbal A, Rucker JJ, Weatherall MW, Sodergren MH. UK Medical Cannabis Registry: A Clinical Outcomes Analysis for Epilepsy. Brain and Behaviour. 2025. doi: https://doi.org/10.1002/brb3.70490
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Erridge S, Hall M, Sodergren MH. Prevalence and Patterns of Cannabis Product Adulteration: An Analysis of WEDINOS Data. Journal of Psychoactive Drugs. 2025. doi: https://www.tandfonline.com/doi/full/10.1080/02791072.2025.2478087
