For millennia, humans have added plants into topical preparations designed for medicinal purposes. Alongside popular herbal remedies like aloe vera, arnica, and witch hazel, cannabis is earning renewed pharmacological attention.
Consumers and researchers alike are intrigued by the possible medicinal benefits of topically applied cannabinoids, like tetrahydrocannabinol (THC) and cannabidiol (CBD). There is so much excitement, in fact, some analysts predict the cannabis topicals market will outpace the growth of the cannabis sector as a whole.
But patients and consumers are not waiting for the results of clinical trials. Cannabinoids are already making their way into skincare lines and sports medicine. But beyond the over-the-counter market, what does the current body of study tell us about its true medicinal potential? Is there a viable future for cannabis within topical plant-based medicines?
Skin Deep: Cannabinoids and the Epidermis
Whether applied through a topical/transdermal application or more popular administration routes like inhaled and oral formulas, the human body interacts with cannabinoids via the endocannabinoid system. This system regulates many biological processes through a network of receptors and chemical neurotransmitters, such as pain, inflammation, mood, memory, and more.
How do cannabis and its various extracts apply to skincare and skin treatment? When inhaled, cannabinoids travel rapidly through the lining of the lungs into the bloodstream. When consumed orally, the digestive tract and liver handle the metabolism of each cannabinoid.
But, when applied topically, cannabinoids interact directly with the endocannabinoid receptors located in the skin. Thus, the endocannabinoid system is a novel new target for skin health and disease research.
As outlined by a 2009 piece in Trends in pharmacological sciences, “It seems that the main physiological function of the cutaneous [endocannabinoid system] is to constitutively control the proper and well-balanced proliferation, differentiation and survival, as well as immune competence and/or tolerance, of skin cells.”
From this perspective, pharmaceutical preparations working through the endocannabinoid system could offer relief for conditions like acne, itch, pain, psoriasis, systemic sclerosis, and cancer.
Unlike with other administration routes, cannabinoids applied topically do not penetrate the bloodstream. A recent small-scale experiment on THC-infused topicals confirmed that “topically applied products did not produce cannabinoid findings in blood or urine.”
This means topical preparations of cannabis do not cause intoxication, even if they contain THC. Because of this, they may be suitable for a much broader demographic than inhaled or oral preparations containing this high-inducing cannabinoid.
Research into Topical Cannabis and Cannabinoids Limited
In 2018, Molecules published “Cannabinoid Delivery Systems for Pain and Inflammation Treatment,” which summarized some of the current research into topical and transdermal cannabinoids for these conditions.
Although this study focused on pain and inflammatory conditions, it found preclinical, clinical, and formulation studies working with cannabinoids for skin conditions. Some of the research the authors highlighted covered cannabis treatment for dermatitis, arthritis, oedema, osteoarthritis, epidermolysis bullosa, and pain/wound management.
In a much more recent study, this time published in 2020, researchers detailed measurable success using topical cannabis-based formulations for non‐uremic calciphylaxis leg ulcers. Specifically, this study examined how cannabinoids could promote wound closure and analgesia.
These publications are noteworthy, but almost all of them remain in the preliminary phases of the study, especially when it comes to THC formulations. The single completed Phase 1 trial aimed to “assess the safety of topical cream (3% CBD and 3% THC), applied twice daily (bid), in healthy subjects, for up to 6 treatment weeks and additional 2 follow-up weeks.” It finished in 2019, but to date there are no published results.
Special Considerations for Topical CBD Research
Although THC may not be getting the scientific attention it deserves, CBD is another matter. Cannabidiol is THC’s non-intoxicating and powerfully anti-inflammatory cousin.
Due to its more favorable legal status, CBD is a primary target for cannabis-based topicals products and already prolific in products like cosmetics, anti-aging creams, and other wellness-style items. However, the research is playing a game of catch-up to the many benefits these products claim to provide.
Still, there are a few preliminary studies, which have no doubt spawned some of these marketing campaigns. For example, in 2014, one study evidenced that CBD’s lipostatic, antiproliferative, and anti-inflammatory effects could benefit those with acne vulgaris. This early research now seems to have led to an observational clinical trial on the condition, sponsored by the CBD brand Charlotte’s Web.
Another interesting study used CBD ointment for inflammatory skin diseases and cutaneous scars. This study, completed in 2019, worked with 20 patients experiencing psoriasis and dermatitis.
Unlike the single THC topical clinical trials coming down the pipeline, at least 10 CBD topical studies are listed in the Clinical Trials database. These trials will investigate the benefits of CBD and hemp-based topicals for psoriasis, osteoarthritis, acne, joint pain, and even anxiety.
A Dire Need for More Research into Cannabis Topical and Transdermal Formulas
Considering the many possible applications for cannabis-based topical medicines and their good safety profiles, it’s strange to see such limited research thus far. With the field of cannabis research exploding, topical routes of administration seem to be getting ignored.
But, if cannabinoid-based topicals and transdermals are to ever legitimately enter the pharmaceutical realm, there is a dire need to focus on final phase clinical trials. Narrowing down specific plant-based formulations, dosing guidelines, and treatment protocols is paramount, hence the development of the RYAH Smart Patch. This revolutionary device will help clinicians (and patients) track delivery history, formula efficacy, and much more.