Medical Cannabis Clinical Evidence

Pain

Chronic neuropathic pain

• Ateş, Gülay, et al. “Cannabis-based medicines for chronic neuropathic pain in adults.” Cochrane Database of Systematic Reviews 1 (2026). cochranelibrary.com
• Wang, Li, et al. “Medical cannabis or cannabinoids for chronic non-cancer and cancer related pain: a systematic review and meta-analysis of randomised clinical trials.” BMJ 374 (2021). bmj.com

Chronic non-cancer pain

• Busse, Jason W., et al. “Medical cannabis or cannabinoids for chronic pain: a clinical practice guideline.” BMJ 374 (2021). bmj.com
• Wang, Li, et al. “Medical cannabis or cannabinoids for chronic non-cancer and cancer related pain: a systematic review and meta-analysis of randomised clinical trials.” BMJ 374 (2021). bmj.com

Cancer pain

• Häuser, Winfried, et al. “Cannabis-based medicines and medical cannabis for adults with cancer pain.” Cochrane Database of Systematic Reviews 6 (2023). cochranelibrary.com

Fibromyalgia

• Lam, Pui Ming, et al. “Analgesic Effect of Cannabinoids for Fibromyalgia: A Systematic Review and Meta-Analysis.” Pain Physician 29.2 (2026): 95-107. researchgate.net

Osteoarthritis/rheumatoid arthritis

• Pramhas, Sibylle, et al. “Oral cannabidiol (CBD) as add-on to paracetamol for painful chronic osteoarthritis of the knee: a randomized, double-blind, placebo-controlled clinical trial.” The Lancet Regional Health–Europe 35 (2023). thelancet.com
• Vela, Jonathan, et al. “Cannabidiol treatment in hand osteoarthritis and psoriatic arthritis: a randomized, double-blind, placebo-controlled trial.” Pain 163.6 (2022): 1206-1214. journals.lww.com

Opioid sparing

• Noori, Atefeh, et al. “Opioid-sparing effects of medical cannabis or cannabinoids for chronic pain: a systematic review and meta-analysis of randomised and observational studies.” BMJ Open 11.7 (2021): e047717. bmjopen.bmj.com

Nausea/Vomiting and Appetite/Wasting

Chemotherapy-induced nausea and vomiting

• Grimison, Peter, et al. “Oral cannabis extract for secondary prevention of chemotherapy-induced nausea and vomiting: Final results of a randomized, placebo-controlled, phase II/III trial.” Journal of Clinical Oncology 42.34 (2024): 4040-4050. ascopubs.org

HIV/AIDS wasting

• Beal, Jeffrey E., et al. “Dronabinol as a treatment for anorexia associated with weight loss in patients with AIDS.” Journal of Pain and Symptom Management 10.2 (1995): 89-97. sciencedirect.com

Cancer cachexia

• Jatoi, Aminah, et al. “Dronabinol versus megestrol acetate versus combination therapy for cancer-associated anorexia: a North Central Cancer Treatment Group study.” Journal of Clinical Oncology 20.2 (2002): 567-573. ascopubs.org
• Strasser, Florian, et al. “Comparison of orally administered cannabis extract and delta-9-tetrahydrocannabinol in treating patients with cancer-related anorexia-cachexia syndrome: a multicenter, phase III, randomized, double-blind, placebo-controlled clinical trial from the Cannabis-In-Cachexia-Study-Group.” Journal of Clinical Oncology 24.21 (2006): 3394-3400. ascopubs.org

Neurological Conditions

Epilepsy

• Devinsky, Orrin, et al. “Randomized, dose-ranging safety trial of cannabidiol in Dravet syndrome.” Neurology 90.14 (2018): e1204-e1211. neurology.org
• Devinsky, Orrin, et al. “Trial of cannabidiol for drug-resistant seizures in the Dravet syndrome.” New England Journal of Medicine 376.21 (2017): 2011-2020. nejm.org
• Miller, Ian, et al. “Dose-ranging effect of adjunctive oral cannabidiol vs placebo on convulsive seizure frequency in Dravet syndrome: a randomized clinical trial.” JAMA Neurology 77.5 (2020): 613-621. jamanetwork.com
• Devinsky, Orrin, et al. “Effect of cannabidiol on drop seizures in the Lennox–Gastaut syndrome.” New England Journal of Medicine 378.20 (2018): 1888-1897. nejm.org
• Thiele, Elizabeth A., et al. “Cannabidiol in patients with seizures associated with Lennox-Gastaut syndrome (GWPCARE4): a randomised, double-blind, placebo-controlled phase 3 trial.” The Lancet 391.10125 (2018): 1085-1096. thelancet.com
• Abu-Sawwa, Renad, Brielle Scutt, and Yong Park. “Emerging use of Epidiolex (cannabidiol) in epilepsy.” The Journal of Pediatric Pharmacology and Therapeutics 25.6 (2020): 485-499. pmc.ncbi.nlm.nih.gov
• Thiele, Elizabeth, et al. “Cannabidiol in patients with Lennox-Gastaut syndrome: interim analysis of an open-label extension study.” Epilepsia 60.3 (2019): 419-428. onlinelibrary.wiley.com

MS spasticity

• Filippini, Graziella, et al. “Cannabis and cannabinoids for symptomatic treatment for people with multiple sclerosis.” The Cochrane Database of Systematic Reviews 2022.5 (2022): CD013444. pmc.ncbi.nlm.nih.gov

Parkinson’s disease

• Messak, Mark, et al. “Therapeutic effects of cannabinoids on Parkinson’s disease: an updated systematic review and meta-analysis of randomized controlled trials.” Acta Neurologica Belgica (2026): 1-20. link.springer.com
• Urbi, Berzenn, et al. “Effects of cannabis in Parkinson’s disease: a systematic review and meta-analysis.” Journal of Parkinson’s Disease 12.2 (2022): 495-508. journals.sagepub.com

ALS/motor neuron disease

• Riva, Nilo, et al. “Safety and efficacy of nabiximols on spasticity symptoms in patients with motor neuron disease (CANALS): a multicentre, double-blind, randomised, placebo-controlled, phase 2 trial.” The Lancet Neurology 18.2 (2019): 155-164. thelancet.com

Spinal cord injury spasticity

• Martins Braga, Fernando, et al. “The effects of nabiximols (Sativex®) on spasticity and non-motor symptoms in chronic spinal cord injury (SCI): a longitudinal prospective study.” Spinal Cord Series and Cases 11.1 (2025): 19. nature.com
• Pooyania, Sepideh, et al. “A randomized, double-blinded, crossover pilot study assessing the effect of nabilone on spasticity in persons with spinal cord injury.” Archives of Physical Medicine and Rehabilitation 91.5 (2010): 703-707. sciencedirect.com

Tourette syndrome

• Mosley, Philip E., et al. “Tetrahydrocannabinol and cannabidiol in Tourette syndrome.” NEJM Evidence 2.9 (2023): EVIDoa2300012. evidence.nejm.org

Dementia-related agitation

• Ruthirakuhan, Myuri T., et al. “Investigating the safety and efficacy of nabilone for the treatment of agitation in patients with moderate-to-severe Alzheimer’s disease: study protocol for a cross-over randomized controlled trial.” Contemporary Clinical Trials Communications 15 (2019): 100385. sciencedirect.com
• Feldman, Oriel J., et al. “Assessment of clinical factors that predict response to nabilone for agitation in Alzheimer’s disease: A post hoc analysis of a randomized placebo-controlled trial.” International Psychogeriatrics (2026): 100183. sciencedirect.com

Migraine/headache

• Only narrative reviews exist. No quality randomized controlled trials.

Huntington’s disease

• Minimal controlled data.

Psychiatric Conditions and Substance Use

Anxiety

• Wilson, Jack, et al. “The efficacy and safety of cannabinoids for the treatment of mental disorders and substance use disorders: a systematic review and meta-analysis.” The Lancet Psychiatry 13.4 (2026): 304-315. thelancet.com
• Coelho, Carly de Faria, et al. “The impact of cannabidiol treatment on anxiety disorders: A systematic review of randomized controlled clinical trials.” Life 14.11 (2024): 1373. mdpi.com
• Han, Kevin, et al. “Therapeutic potential of cannabidiol (CBD) in anxiety disorders: A systematic review and meta-analysis.” Psychiatry Research 339 (2024): 116049. sciencedirect.com

Depression

• Wilson, Jack, et al. “The efficacy and safety of cannabinoids for the treatment of mental disorders and substance use disorders: a systematic review and meta-analysis.” The Lancet Psychiatry 13.4 (2026): 304-315. thelancet.com

ADHD

• Wilson, Jack, et al. “The efficacy and safety of cannabinoids for the treatment of mental disorders and substance use disorders: a systematic review and meta-analysis.” The Lancet Psychiatry 13.4 (2026): 304-315. thelancet.com

Substance use disorders

• Wilson, Jack, et al. “The efficacy and safety of cannabinoids for the treatment of mental disorders and substance use disorders: a systematic review and meta-analysis.” The Lancet Psychiatry 13.4 (2026): 304-315. thelancet.com
• Dimech, David Zammit, et al. “Cannabinoid exposure across substance use disorders: Short-term symptom benefits without sustained therapeutic gains in a tier-weighted systematic review.” European Psychiatry 69.1 (2026): e73. cambridge.org

Schizophrenia/psychosis

• McGuire, Philip, et al. “Cannabidiol (CBD) as an adjunctive therapy in schizophrenia: a multicenter randomized controlled trial.” American Journal of Psychiatry 175.3 (2018): 225-231. psychiatryonline.org
• Boggs, Douglas L., et al. “The effects of cannabidiol (CBD) on cognition and symptoms in outpatients with chronic schizophrenia a randomized placebo controlled trial.” Psychopharmacology 235.7 (2018): 1923-1932. link.springer.com
• Leweke, F. Markus, et al. “Cannabidiol and amisulpride improve cognition in acute schizophrenia in an explorative, double-blind, active-controlled, randomized clinical trial.” Frontiers in Pharmacology 12 (2021): 614811. frontiersin.org
• Di Francesco, Antonio, et al. “Cannabidiol for the treatment of positive and negative symptoms in schizophrenia spectrum disorders: a systematic review and meta-analysis.” European Archives of Psychiatry and Clinical Neuroscience (2026): 1-10. link.springer.com

PTSD

• Roepke, Stefan, et al. “Dronabinol for nightmares in post-traumatic stress disorder: a randomized controlled trial.” Nature Medicine (2026): 1-10. nature.com

Sleep/insomnia

• Bhagavan, Chiranth, et al. “Cannabinoids in the Treatment of Insomnia Disorder: A Systematic Review and Meta-Analysis.” CNS Drugs 34.12 (2020): 1217-1228. link.springer.com
• Narayan, Andrea J., et al. “Cannabidiol for moderate–severe insomnia: a randomized controlled pilot trial of 150 mg of nightly dosing.” Journal of Clinical Sleep Medicine 20.5 (2024): 753-763. link.springer.com
• Lavender, Isobel G., et al. “Cannabinol for Acute Treatment of Insomnia Disorder in a Randomized Placebo-Controlled Crossover Trial.” Journal of Sleep Research 35.4 (2026): e70284. onlinelibrary.wiley.com
• da Silva, Giovanna Hanike Santos, et al. “Effectiveness of Cannabinoids for Improving Sleep Quality in People with and without Insomnia or Poor Sleep: A Systematic Review and Meta-Analysis of Randomised Studies.” Sleep Medicine Reviews (2025): 102156. sciencedirect.com

Gastrointestinal

IBD (Crohn’s, ulcerative colitis)

• Kafil, Tahir S., et al. “Cannabis for the treatment of Crohn’s disease and ulcerative colitis: evidence from Cochrane reviews.” Inflammatory Bowel Diseases 26.4 (2020): 502-509. academic.oup.com
• Jugl, Sebastian, et al. “Effectiveness of THC-containing cannabis for inflammatory bowel disease: a systematic review.” Journal of Cannabis Research (2026). link.springer.com
• Vaid, Rayyan, et al. “Cannabis use in Crohn’s disease: a systematic review and meta-analysis of randomized controlled trials (RCTs).” Irish Journal of Medical Science 194.2 (2025): 439-446. link.springer.com

Irritable bowel syndrome

• No quality RCT evidence of benefit.

Ophthalmology

Glaucoma

The American Academy of Ophthalmology (2014 reaffirmed) and the American Glaucoma Society position statement both state cannabis is not recommended. While THC transiently lowers intraocular pressure (roughly 3-4 hours, ~18-20mg THC needed), the short duration of action, systemic side effects, and blood pressure lowering (potentially reducing optic-nerve perfusion) make it impractical and potentially harmful versus standard therapies. Novel controlled-deactivation CB1 agonists and MAGL inhibitors remain experimental.

• Jampel, Henry. “American Glaucoma Society position statement: marijuana and the treatment of glaucoma.” Journal of Glaucoma 19.2 (2010): 75-76. ovid.com
• American Academy of Ophthalmology. “Marijuana and Glaucoma: A Shifting Landscape.” EyeNet (2022). aao.org
• American Academy of Ophthalmology. “Why Eye Doctors Don’t Recommend Marijuana for Glaucoma” (infographic). aao.org

Women’s Health

Endometriosis/pelvic pain

• Scoping reviews; no RCTs.
• Calleson Cummings, Savannah, et al. “Evaluating the current evidence for the efficacy of cannabis in symptom management of endometriosis-associated pain.” Integrative Medicine Reports 3.1 (2024). journals.sagepub.com
• McLaren, Kindha, Simon Erridge, and Mikael H. Sodergren. “A scoping systematic review of cannabis use in endometriosis.” Australian and New Zealand Journal of Obstetrics and Gynaecology 66.1 (2026): e70081. obgyn.onlinelibrary.wiley.com
• 2024 American College of Obstetricians and Gynecologists Clinical Consensus on cannabis for gynecologic pain notes insufficient evidence and highlights PEA (palmitoylethanolamide) data. acog.org
• Four ongoing RCTs.

Pediatric

Autism spectrum disorder

• Branco, L. Cappelleti Beneti, et al. “Efficacy and Safety of Cannabidiol Cannabis Extracts for Children and Adolescents with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.” European Psychiatry 68.Suppl 1 (2025): S140. doi.org
• Trauner, Doris, et al. “Cannabidiol (CBD) treatment for severe problem behaviors in autistic boys: a randomized clinical trial.” Journal of Autism and Developmental Disorders (2025): 1-14. link.springer.com
• Aran, Adi, et al. “Cannabinoid treatment for autism: a proof-of-concept randomized trial.” Molecular Autism 12.1 (2021): 6. link.springer.com

Minor Cannabinoids

Cannabigerol (CBG)

• Cuttler, Carrie, et al. “Acute effects of cannabigerol on anxiety, stress, and mood: a double-blind, placebo-controlled, crossover, field trial.” Scientific Reports 14.1 (2024): 16163. nature.com

Tetrahydrocannabivarin (THCV)

• Jadoon, Khalid A., et al. “Efficacy and safety of cannabidiol and tetrahydrocannabivarin on glycemic and lipid parameters in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled, parallel group pilot study.” Diabetes Care 39.10 (2016): 1777-1786. diabetesjournals.org

Cannabinol (CBN)

• Hausenblas, Heather, Stephanie Hooper, and Tarah Lynch. “Effectiveness of a Cannabinoids Supplement on Sleep and Mood in Adults With Subthreshold Insomnia: A Randomized Double-Blind Placebo-Controlled Crossover Pilot Trial.” Health Science Reports 8.2 (2025): e70481. onlinelibrary.wiley.com

CBC, CBDA, THCA

• No controlled human clinical trials exist. Claims are preclinical or anecdotal only.

Harms and Safety Literature

Cardiovascular

• Storck, Wilhelm, et al. “Cardiovascular risk associated with the use of cannabis and cannabinoids: a systematic review and meta-analysis.” Heart 111.22 (2025): 1047-1056. heart.bmj.com
• Glantz, Stanton, and Lynn Silver. “It is time to treat cannabis as an important risk factor for cardiovascular disease.” Heart 111.22 (2025): 1043-1044. heart.bmj.com
• Jeffers, Abra M., et al. “Association of cannabis use with cardiovascular outcomes among US adults.” Journal of the American Heart Association 13.5 (2024): e030178. ahajournals.org
• Kamel, Ibrahim, et al. “Myocardial infarction and cardiovascular risks associated with cannabis use: a multicenter retrospective study.” JACC: Advances 4.5 (2025): 101698. jacc.org

Cannabis use disorder in medicinal users

• Dawson, Danielle, et al. “The prevalence of cannabis use disorders in people who use medicinal cannabis: A systematic review and meta-analysis.” Drug and Alcohol Dependence 257 (2024): 111263. sciencedirect.com

Drug interactions

• Geffrey, Alexandra L., et al. “Drug–drug interaction between clobazam and cannabidiol in children with refractory epilepsy.” Epilepsia 56.8 (2015): 1246-1251. onlinelibrary.wiley.com
• Herdegen, Thomas, and Ingolf Cascorbi. “Drug interactions of tetrahydrocannabinol and cannabidiol in cannabinoid drugs: recommendations for clinical practice.” Deutsches Ärzteblatt International 120.49 (2023): 833. pmc.ncbi.nlm.nih.gov

Pregnancy

• Lo, Jamie O., et al. “Prenatal cannabis use and neonatal outcomes: a systematic review and meta-analysis.” JAMA Pediatrics 179.7 (2025): 738-746. jamanetwork.com
• Sorkhou, Maryam, et al. “Birth, cognitive and behavioral effects of intrauterine cannabis exposure in infants and children: A systematic review and meta-analysis.” Addiction 119.3 (2024): 411-437. onlinelibrary.wiley.com
• Baia, Ines, and Rosa MSM Domingues. “The effects of cannabis use during pregnancy on low birth weight and preterm birth: a systematic review and meta-analysis.” American Journal of Perinatology 41.01 (2024): 017-030. thieme-connect.com

Psychosis (dose-response)

• Di Forti, Marta, et al. “The contribution of cannabis use to variation in the incidence of psychotic disorder across Europe (EU-GEI): a multicentre case-control study.” The Lancet Psychiatry 6.5 (2019): 427-436. thelancet.com

Older adults/cognitive effects

• National Academies of Sciences, Engineering, and Medicine. “Health effects of marijuana and cannabis-derived products presented in new report.” Released January 12, 2017. nationalacademies.org
• Souza, José Diogo R., et al. “Adverse effects of oral cannabidiol: an updated systematic review of randomized controlled trials (2020–2022).” Pharmaceutics 14.12 (2022): 2598. mdpi.com