The Cannabis Act (Bill C-45) took effect on October 17, 2018, making Canada the second country to legalize recreational marijuana after Uruguay. So it’s high time that we covered the possibilities that cannabis can open up. Bad puns aside, cannabis legalization opens up the floodgates for medical research in many ways, and will likely have an impact on dermatology, as well as the larger skincare market.
Politics make for entertaining narratives – social collapse, moral decay, and the apocalypse vs. the end of disease, crime, and war – a utopia. Contrary to the seeming hype on the news, for the average Canadian, October 17th, 2018, went by like another sleepy Wednesday. Most smokers and non-smokers alike seemed about as excited or terrified as if they had found out that kale was now legal. On the medical side of things, though, things may be more exciting.
Where Medicinal Cannabis Stands
Medicinal use of cannabis dates back thousands of years; knowledge of their psychoactive effects and their therapeutic effects is nothing new.1 The discovery of the endocannabinoid system (ECS) and a more modern scientific understanding of its impact is. We have cannabinoid receptors throughout our bodies and in our skin as well. It has wide-reaching effects, and from a therapeutic perspective, it could have numerous potential benefits.2
THC (tetrahydrocannabinol) and CBD (cannabidiol) are often understood as the “get high” part and the “medicinal” part, respectively. This is true for what it’s worth – THC is psychoactive, while CBD is not, and CBD actually tends to suppress the high. Still, both compounds interact with the endocannabinoid system via the cannabinoid receptors in your body. Both compounds have similar therapeutic potential – it is not that THC is only useful for getting high.3
It’s also worth noting that there is somewhat of a black box effect in play due to a wide-reaching restriction on production and supply. While Canada doesn’t exactly mirror U.S. drug scheduling laws, researchers must apply for an exemption to obtain controlled substances for research purposes from Health Canada, adding a big obstacle and securing funding likely presents an even larger one.4 In terms of research, especially in the United States, there is a familiar paradox of bureaucracy:
You need substantial scientific evidence to reschedule drugs as having medicinal benefits, but the severe restrictions on their production and availability are precisely what makes research difficult to get done in the first place.5
At present, much of the data that we rely on comes from a few countries such as Israel and Spain, which have pushed research in this field, but this may be about to change6 as more economic incentives push to fund research.
The Weight of Evidence
So far, the best, weighted evidence we have in terms of the overall efficacy of cannabis is a 2017 review of over 10,000 medical articles related to cannabis, The Health Effects of Cannabis and Cannabinoids. It’s around 400 pages, but there is a more succinct summary of its findings here.7 Below is a further shortlisting of where the evidence currently stands:
Benefits
| Strong Evidence | Moderate Evidence | No/Insufficient Evidence |
| Chronic pain in adults | Short term benefits for sleep apnea | All Cancers |
| Anti-nausea and vomit | Better cognitive performance for people with psychotic disorders and a history of cannabis use | Epilepsy |
| Some symptoms of MS |
Risks
| Strong Evidence | Moderate Evidence | No/Insufficient Evidence |
| Respiratory problems, chronic bronchitis | Increased risk of suicidal ideation | Impaired academic performance, educational attainment, social engagement |
| Increased risk of vehicular accidents | Social anxiety disorder | Death from overdose |
| Low birth weight in babies | Develop anxiety disorder | |
| Increases risk of schizophrenia and other psychoses | Asthma when controlled for cigarette smoking |
Notable is the lack of high-quality evidence pointing at cancer cures and epilepsy, which often spikes media attention. On the other hand, commonly believed risks such as impaired academic performance or educational attainment also have no basis in evidence. Note that this doesn’t mean that this is the final judgment on the medicinal benefits or risks of cannabis. It’s only the state of what the best evidence points at, as of 2017. The science will undoubtedly evolve as more studies come in, and the more speculative applications will either get debunked or will garner more supporting evidence.
Dermatological Application
In terms of dermatology and the larger area of skincare, we are still in the zone of speculation in terms of the level of evidence. There aren’t as many high-quality cannabis studies for treating dermatological conditions as there are for something like chronic pain. However, looking at the mechanisms of action, these are areas that show the most promise:
Immunosuppressive properties: Atopic dermatitis, allergic contact dermatitis, sclerosis
Anti-inflammatory properties: Acne
Antipruritic properties: Allergic contact dermatitis, many other conditions where itching is a major symptom
Anti-neoplastic properties: It could have relevance for both melanoma and non-melanoma skin cancers.
The endocannabinoid system affects the whole body, and in the skin specifically, it may influence keratinocytes, melanocytes, and sebocytes. Therefore, the potential application is wide-ranging, and we could see the uses of cannabis in numerous conditions. One cautionary note, though:
Hype is already a thing in this industry where lore can quickly become law.8
At this stage, the evidence is mixed, and there are many unknowns. Many cannabinoids have both anti and pro-inflammatory or neoplastic responses that may have to do with concentration. Many questions remain, including, how the drug is best used – as a topical or edible, dosage, and application. As more high-quality studies (double-blind, placebo-controlled) come in, cannabis products will certainly find their applications in dermatology.
Skincare and OTC
The potential for topical application in skin care is also an exciting area that has potential. This isn’t “getting high on cosmetics,” of course, but beauty products that will contain cannabis in some form to produce the desired effect. The rigor for efficacy is not nearly as high as prescription drugs, and there will certainly be substantial interest. We expect cannabinoid compounds to make a big splash in the general skincare market in the coming years.
1 https://www.sciencedirect.com/science/article/pii/S0378874106000821?via%3Dihub
2 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3997295/
3 https://www.healthline.com/health/cbd-vs-thc#medical-benefits
4 https://www.the-scientist.com/news-opinion/canada-could-come-to-the-fore-in-cannabis-research-64455
5 https://www.vox.com/2014/9/25/6842187/drug-schedule-list-marijuana
6 https://420intel.com/articles/2018/04/20/6-most-advanced-countries-marijuana-research
7 If you can tolerate the author’s skeptic snark – but the content itself is a fair summary of the report.
8 https://www.scientificamerican.com/article/some-of-the-parts-is-marijuana-rsquo-s-ldquo-entourage-effect-rdquo-scientifically-valid/
