Health Benefits of Medicinal Cannabis

 PubMed references over 20,000 published studies or reviews under the search terms cannabis, cannabinoid or marijuana, nearly half of which were published within the last five years.   PubMed is a search engine accessing primarily the MEDLINE database of references and abstracts on life sciences and biomedical topics and from peer reviewed journals. 

 By comparison, few pharmaceutical medicines are tested in multiple, large-scale clinical trials or have thousands of years of actual experience behind them.  

Some of medicinal Cannabis proven benefits include: 

  • Relieves pain  and  inflammation
  • Reduces anxiety
  • Relieves nausea
  • Helps to  fight cancer (Other possible effects that may prove beneficial in the oncology population include analgesia, antitumor effect, mood elevation, muscle relaxation, and relief of insomnia ) 
  • Promotes cardiovascular health
  • May treat seizures and other neurological disorders including Alzheimers      ( 2007. British Journal of Pharmacology: “Cannabinoids offer a multi-faceted approach for the treatment of Alzheimer's disease by providing neuroprotection and reducing neuroinflammation, whilst simultaneously supporting the brain's intrinsic repair mechanisms...”  )


Cannabinoids and Chronic Pain


 Chronic pain is the condition for which cannabis is most widely used. It seems to be particularly effective in neuropathic pain for which opioids, NSAIDs and other pharmaceutical medicines are not effective. It also appears to reduce the required dose when used in conjunction with opioids. The following studies add support to the growing evidence:

  • Comparison of the Analgesic Effects of Dronabinol and Smoked Marijuana in Daily Marijuana Smokers. Neuropsychopharmacology, 2013. 
  •  These data indicate that under controlled conditions, marijuana and dronabinol decreased pain, with dronabinol producing longer-lasting decreases in pain sensitivity and lower ratings of abuse-related subjective effects than marijuana. 

  •  Cannabis in painful HIV-associated sensory neuropathy: A randomized placebo-controlled trial. Neurology, 2007. 

  •  A Randomized, Placebo Controlled Cross-Over Trial of Cannabis Cigarettes in Neuropathic Pain. J.Pain, 2007. 

  •  Smoked Medicinal Cannabis for Neuropathic Pain in HIV: A randomized, cross-over clinical trial. Neuropsychopharmacology, 2008. 

  •  Smoked cannabis for chronic neuropathic pain: a randomized controlled trial. CMAJ, 2010. 
  •  Conclusion: A single inhalation of 25 mg of 9.4% tetrahydrocannabinol herbal cannabis three times daily for five days reduced the intensity of pain, improved sleep and was well tolerated. Further long-term safety and efficacy studies are indicated. (International Standard Randomised Controlled Trial Register no. ISRCTN68314063


Cannabinoids and Cancer


  •  Cannabis Extract Treatment for Terminal Acute Lymphoblastic Leukemia with a Philadelphia Chromosome Mutation. Case Rep Oncol. 2013. 
  • Towards the use of cannabinoids as antitumour agents. Nat Rev Cancer. 2012

  •  Cannabinoids and cancer: potential for colorectal cancer therapy. Biochem Soc Trans. 2005. 

  • Cannabidiol as potential anticancer drug. Br J Clin Pharmacol. 2013. 

  •  Cannabinoids: a new hope for breast cancer therapy? Cancer Treat Rev. 2012

  • Cannabinoids for Cancer Treatment: Progress and Promise. Cancer Res. 2008. 

  •  Non-hallucinogenic cannabinoids are effective anti-cancer drugs. Anticancer Research, 2013.

  • The Combination of Cannabidiol and Δ9-Tetrahydrocannabinol Enhances the Anticancer Effects of Radiation in an Orthotopic Murine Glioma Model. Mol.Cancer.Ther. 2014. 

  • The intersection between cannabis and cancer in the United States. CROH, 2011. 

  •  A pilot clinical study of Δ9-tetrahydrocannabinol in patients with recurrent glioblastoma multiforme, British Journal of Cancer, 2006 

  •   Cannabis, cannabinoids and cancer – the evidence so far. Cancer Research UK, 2014. 


  •  Cannabidiol Induces Programmed Cell Death in Breast Cancer Cells by Coordinating the Cross-talk between Apoptosis and Autophagy. Mol Cancer Ther., 2011. 


Cannabinoids and Crohn's Disease


  • A Pilot Study of GWP42003 in the Symptomatic Treatment of Ulcerative Colitis. GW Pharma, 2014. 

  • Impact of Cannabis Treatment on the Quality of Life, Weight and Clinical Disease Activity in Inflammatory Bowel Disease Patients: A Pilot Prospective Study. Digestion, 2012. 

  • Cannabis Induces a Clinical Response in Patients With Crohn’s Disease: A Prospective PlaceboControlled Study. Clin Gastroenterol Hepatol. 2013. 3565(13)00604-6/pdf 

  •  Cannabis use amongst patients with inflammatory bowel disease. Eur J Gastroenterol Hepatol. 2011. 

  •  Cannabis Finds Its Way into Treatment of Crohn’s Disease. Pharmacology, 2014. .



Medicinal Cannabis: The Evidence


 Drugs. 2018 Nov;78(17):1791-1804. doi: 10.1007/s40265-018-0992-5.

Efficacy and Safety of Cannabidiol in Epilepsy: A Systematic Review and Meta-Analysis.

Lattanzi S1, Brigo F2,3, Trinka E4,5,6, Zaccara G7, Cagnetti C8, Del Giovane C9, Silvestrini M8.


Adjunctive CBD in patients with LGS or DS experiencing seizures uncontrolled by concomitant anti-epileptic treatment regimens is associated with a greater reduction in seizure frequency and a higher rate of AEs than placebo.

 CNS Drugs. 2018 Oct;32(10):905-916. doi: 10.1007/s40263-018-0558-9.

Efficacy and Safety of Adjunctive Cannabidiol in Patients with Lennox-Gastaut Syndrome: A Systematic Review and Meta-Analysis.

Lattanzi S1, Brigo F2,3, Cagnetti C4, Trinka E5,6,7, Silvestrini M4.



Adjunctive CBD resulted in a greater reduction in seizure frequency and a higher rate of AEs than placebo in patients with LGS presenting seizures uncontrolled by concomitant  approved antiepileptic drugs  

J Neurol Neurosurg Psychiatry. 2018 Jul;89(7):741-753. doi: 10.1136/jnnp-2017-317168. Epub 2018 Mar 6.

Evidence for cannabis and cannabinoids for epilepsy: a systematic review of controlled and observational evidence.

Stockings E1, Zagic D1, Campbell G1, Weier M1, Hall WD2,3, Nielsen S1, Herkes GK4, Farrell M1, Degenhardt L1. 

 Pharmaceutical-grade CBD as adjuvant treatment in paediatric-onset drug-resistant epilepsy may reduce seizure frequency. Existing RCT evidence is mostly in paediatric samples with rare and severe epilepsy syndromes; randomized controlled trieals examining other syndromes and cannabinoids are needed. 

 BMJ. 2019 Feb 5;364:l574. doi: 10.1136/bmj.l574.

WHO proposes rescheduling cannabis to allow medical applications.

Mayor S1. 

 CNS Drugs. 2003;17(3):179-202.

Therapeutic potential of cannabinoids in CNS disease.

Croxford JL1. 

 This review highlights recent advances in understanding of the endocannabinoid system and indicates CNS disorders that may benefit from the therapeutic effects of cannabinoid treatment. Where applicable, reference is made to ongoing clinical trials of cannabinoids to alleviate symptoms of these disorders. 

 Support Care Cancer. 2003 Mar;11(3):137-43. Epub 2002 Aug 21.

Established and potential therapeutic applications of cannabinoids in oncology.

Walsh D1, Nelson KA, Mahmoud FA

 The two proven indications for the use of the synthetic cannabinoid (dronabinol) are chemotherapy-induced nausea and vomiting and AIDS-related anorexia. Other possible effects that may prove beneficial in the oncology population include analgesia, antitumor effect, mood elevation, muscle relaxation, and relief of insomnia. Two types of cannabinoid receptors, CB1 and CB2, have been detected. CB1 receptors are expressed mainly in the central and peripheral nervous system. CB2 receptors are found in certain nonneuronal tissues, particularly in the immune cells. Recent discovery of both the cannabinoid receptors and endocannabinoids has opened a new era in research on the pharmaceutical applications of cannabinoids. The use of cannabinoids should be continued in the areas indicated, and further studies are needed to evaluate other potential uses in clinical oncology. 

Expert Opin Investig Drugs. 2019 Mar;28(3):285-296. doi: 10.1080/13543784.2019.1561859. Epub 2018 Dec 29.

Cannabis for cancer - illusion or the tip of an iceberg: a review of the evidence for the use of Cannabis and synthetic cannabinoids in oncology.

Turgeman I1, Bar-Sela G2,3. 

 Expert opinion: Sufficient evidence supports the use of Cannabis for palliative indications in oncology; however, patients should be carefully selected, guided and followed. Promising research suggests the potent antineoplastic activity, but more data must be accrued. 

 Eur Arch Psychiatry Clin Neurosci. 2019 Jan 31. doi: 10.1007/s00406-019-00984-4. [Epub ahead of print]

How effective and safe is medical cannabis as a treatment of mental disorders? A systematic review.

Hoch E1, Niemann D2, von Keller R2, Schneider M3, Friemel CM2, Preuss UW4, Hasan A2, Pogarell O2. 

 THC- and CBD-based medicines, given as adjunct to pharmaco- and psychotherapy, were associated with improvements of several symptoms of mental disorders, but not with remission. Side effects occurred, but severe adverse effects were mentioned in single cases only. 

 Recenti Prog Med. 2008 Dec;99(12):616-24.

[Cannabinoids in the control of pain].

[Article in Italian]Shaladi AM1, Crestani F, Tartari S, Piva B

 Pain Manag. 2019 Jan 25. doi: 10.2217/pmt-2018-0051. [Epub ahead of print]

Perspectives on cannabis as a substitute for opioid analgesics.

Khan SP1, Pickens TA1, Berlau DJ1.

With the opioid epidemic reaching new heights in the USA, it has become critical to find suitable alternatives to opioids. Cannabis, an antinociceptive, is a strong contender to help patients reduce their opioid usage. A growing literature has been examining the complex effects cannabis has on pain relief and on opioid usage; whether it is a substitute for opioids or increases their use. This review explores the studies that compare cannabis-opioid interactions and presents some challenges of cannabis research and usage. The practical clinical pharmacology of cannabis as an analgesic, including the route of administration, safety and pharmacokinetics, are discussed to address the concerns, as well as possible solutions, of cannabis as a pain reliever.

 Front Pharmacol. 2018 Nov 13;9:1259. doi: 10.3389/fphar.2018.01259. eCollection 2018.

Cannabinoids and Pain: New Insights From Old Molecules.

Vučković S1, Srebro D1, Vujović KS1, Vučetić Č2,3, Prostran M1. 


The evidence from current research supports the use of medical cannabis in the treatment of chronic pain in adults. Careful follow-up and monitoring of patients using cannabis/cannabinoids are mandatory.