Medical Research Trending Applications

CBD – Antibacterial Agent?

Written by Loren Devito, PhD

Evidence to date

Cannabidiol (CBD) can do wonders for the body and brain. And cumulative clinical evidence is substantiating many anecdotal tales from daily CBD users. But, while many satisfied CBD consumers have benefitted from the internal benefits of this cannabinoid, they may be missing out on its external benefits.

CBD exists in many forms–as oils, tinctures, edibles, and vapes. However, what many people often forget is that CBD can be applied to the skin in topical forms, such as creams and lotions. These salves can be very effective to treat localized pain and inflammation and do not require consumption to achieve relief. This method can be very convenient for people with arthritis or those who would rather not use systemic CBD.

But topicals have another trick up their sleeve–they may also be used as an antibacterial. In 1976, researchers published a report on the antibacterial properties of tetrahydrocannabinol (THC) and CBD. The journal in which they published was named after Antonie van Leeuwenhoek, who is known as the “Father of Microbiology” due to his discovery of bacteria. In this report, researchers applied extracts of CBD, THC, or both to plates growing staphylococci (which causes “staph” infections) and streptococci (which causes “strep” throat), which are types of “Gram-positive” bacteria. [1] The results showed that both CBD and THC are effective antibacterial agents against Gram-positive but not Gram-negative bacteria.

A more recent study found similar results. While both CBD and THC were found to possess antibacterial properties, they were only effective against Gram-positive bacteria [2]. In addition, CBD had higher antimicrobial activity compared to THC; a CBD/THC mixture also had higher antimicrobial activity compared to THC alone. Results of both studies together suggest that CBD may be used as an effective antimicrobial against Gram-positive bacteria.

But what about really tough types of bacteria that don’t seem to respond to current medications? There is some evidence that CBD may be powerful enough to tackle those strains as well.

A study published in 2008 evaluated the effectiveness of five cannabinoids, including THC and CBD, on methicillin-resistant Staphylococcus aureus, or MRSA [3]. This group of Gram-positive bacteria is known as a “super-bug” that causes very difficult-to-treat infections that current medications cannot treat. MRSA is a growing problem as it spreads easily through hospitals and can cause significant harm.

All cannabinoids tested in this study showed potent antibacterial activity against MRSA strains, suggesting that CBD may in fact be tough enough to fight the most difficult-to-target bacteria. It’s of extreme importance to note that these are anti-bacterial properties and not anti-viral. CBD and other cannabinoids should not be used alone in an attempt to treat COVID-19 or any other virus, as we don’t have scientific evidence to support that currently.

Before you swap out all of your antibacterials for CBD, additional research is required to confirm these effects. There are certainly many benefits of using CBD topicals so, for now, continue to use salves and creams (or give them a try!), knowing you may be getting an added antibacterial boost as we await further evidence.

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  1. van Klingeren, B., ten Ham, M., “Antibacterial Activity of Δ9-tetrahydrocannabinol and Cannabidiol”, Antonie van Leeuwenhoek, 1976, Volume 42, pg. 9-12.
  2. Lelario, G., et al., “Identification and Antimicrobial Activity of Most Representative Secondary Metabolites from Different Plant Species”, Chemical and Biological Technologies in Agriculture, 2018, Volume 5, pg. 1-12.
  3. Appendino, G., et al., “Antibacterial Cannabinoids from Cannabis sativa: A Structure-activity Study”, J Nat Prod, 2008, Volume 71, pg. 1427-1430.

About the author

Loren Devito, PhD

Loren DeVito, PhD is a neuroscientist and science writer with expertise in cannabis science and medicine. She is committed to communicating evidence-based information about cannabis and its healing properties. Learn more about her work at