hit counter

Is cannabidiol effective against COVID-19?

Coronavirus disease 2019 (COVID-19), caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused over 6.4 million deaths so far.

A new Cannabis and cannabinoid research Journal study discusses the utility of cannabidiol (CBD) in treating the inflammatory symptoms of COVID-19. This treatment approach could help halt or reduce the progression of COVID-19, potentially reducing its severity and mortality rate.

Study: Cannabidiol as a Treatment for COVID-19 Symptoms?  A critical review.  Image source: r.classen / Shutterstock.com

To learn: Cannabidiol as a Treatment for COVID-19 Symptoms? A critical review. Image source: r.classen / Shutterstock.com


COVID-19 is associated with a wide range of manifestations from mild to life-threatening illness. The hyperinflammatory response to SARS-CoV-2 is thought to be responsible for severe symptoms affecting multiple organ systems.

A wide range of drugs have been studied for their ability to mitigate the severity of COVID-19. These include dexamethasone, a powerful corticosteroid with anti-inflammatory and immunosuppressive activity; remdesivir, a nucleoside analogue that inhibits viral replication; Hydrochloroquine, an antimalarial immunomodulatory agent, convalescent plasma containing antibodies specific to the virus, and SARS-CoV-2 monoclonal antibodies.

Of these, only dexamethasone has shown a clear improvement in outcomes in a specific patient population. Notably, this steroid has not been studied for its usefulness in treating early-stage COVID-19.

Meanwhile, remdesivir is useful only for hospitalized patients with a relatively long course of treatment that requires parenteral administration. In addition, immunomodulators can have systemic effects.

Monoclonal antibodies are currently approved for use in patients with early disease who are at high risk for severe COVID-19 disease.

Paxlovid and molnupiravir have received an Emergency Use Authorization (EUA) for the treatment of high-risk COVID-19 positive patients. These remedies are only suitable for people with early symptoms who are not receiving other treatment for severe COVID-19.

The need for safe and effective early interventions has prompted investigations into potentially useful drugs for COVID-19. One of them is CBD, which acts on the endocannabinoid CB1 and CB2 receptors in the brain, as well as on the adenosine A2A receptors. These receptors are widespread in the human body.

CBD received orphan drug approval in 2018 to treat a form of epilepsy. It is also known to have immunosuppressive and anti-inflammatory effects due to the expression of CB2 receptors in immune cells in the gut, lungs and immune organs.

CBD in low doses can increase the intoxication caused by other cannabis metabolites, especially tetrahydrocannabidiol (THC); however, it appears to counteract such effects at high doses. Importantly, CBD is not known to cause dependency or addiction.

Side effects of CBD include drowsiness, fever, loss of appetite, abnormal behavior, and euphoria. Further research is needed to determine the relevance of these side effects after chronic use.

The current review summarizes the current knowledge on the effects of CBD on COVID-19-related inflammation and respiratory symptoms from studies published between September and December 2020.

study results

Of the nine papers that were eligible for inclusion in the study, there were five in vivo studies and three were in vitro Human tissue studies. None of the animal models had COVID-19; However, they have been used to determine the effects of CBD on acute pneumonia or injury, asthma, and acute respiratory distress syndrome (ARDS).

CBD has been reported to decrease several inflammatory cytokines and reduce ARDS symptoms. Inflammatory infiltration of the lungs as well as decreased protein exudation, inflammatory cytokine levels, and myeloperoxidase levels were observed in response to CBD. Asthma-related inflammation was similarly reduced.

In which in vitro In human tissue models, CBD treatment has been associated with lower expression of A2A receptors and reduced inflammation. Compared to dexamethasone, CBD reduced inflammatory signaling induced by lipopolysaccharide, which is a potent bacterial inflammation-inducing antigen

A single human randomized clinical trial (RCT) of CBD treatment in patients with mild to moderate COVID-19 was also available. To this end, no significant improvement was reported for CBD compared to controls in prevention of severe disease, reduced symptom duration, lower cytokine levels, reduced lung damage, hospitalization, or mortality. The psychological symptoms also did not differ between the groups.

A single open-label study reported less burnout and emotional exhaustion after treatment with CBD among COVID-19 frontline workers. However, 10% of the study participants reported serious adverse events, although all made a full recovery.

In a more recent study, not included in the current review, researchers identify some evidence of an endoplasmic reticulum-mediated effect of CBD on SARS-CoV-2 that inhibits replication. It cited data from the National COVID Cohort Collaborative Database showing lower rates of positive COVID-19 test results with CBD treatment.


Although the current evidence does not support the use of CBD in treating COVID-19, there remains an urgent need for further studies. These should investigate different dosage levels with CBD of a certain purity for prophylactic and therapeutic purposes given the promising anti-inflammatory activity observed with this molecule in vitro.

Drug interactions also need to be investigated, especially since the treatment of COVID-19 currently involves the use of many anti-inflammatory and immunomodulatory drugs.

Its anti-inflammatory properties could also be detrimental in suppressing the immune response, which could suppress the ability to fight off infection, so the risk of viral and respiratory infections could be higher.”

Overall, there is insufficient evidence to support or disapprove CBD in treating COVID-19.

Magazine reference:

  • Holst, M. Nowak, D., & Hoch, E. (2022). Cannabidiol as a Treatment for COVID-19 Symptoms? A critical review. Cannabis and cannabidiol research. doi:10.1089/can.2021.0135.

Leave a Comment