Cannabinoids (CBD) can come from medical marijuana plants or from industrially grown hemp plants. Both are varieties of Cannabis (Cannabis sativa), but they are grown for different purposes, and each one comes with its own legal status. CBD extracts, which are produced directly from cannabis flowers, are up to 15 percent CBD (150,000 ppm). CBD extracts can be produced indirectly from hemp manufacture as a by-product of the flowers and leaves that are mixed in with the stalks during hemp stalk processing for fiber. CBD from hemp plants are usually only 25 ppm (vs. 150,000 ppm from cannabis flowers).

Cannabinoids from Industrial Hemp

CBD is not a product or component of hemp seeds, and labeling to that effect is misleading and motivated by the desire to take advantage of the legal gray area of CBD under federal law.¹

Most CBD in products mislabeled as “hemp oil" are a product of large-scale hemp stalk and fiber processing facilities in Europe where the fiber is the primary material produced at a large scale.

But, as mentioned above, a small amount of CBD may be in industrial hemp if flowers and leaves and mixed in with the stalks during hemp stalk processing for fiber.

Cannabinoids and Skin Health

First isolated from cannabis in 1940 by Roger Adams, the structure of CBD was not completely understood until 1963. Early studies resulted in the accepted view that THC was the “active" principle of cannabis and research then focused primarily on it to the virtual exclusion of CBD. This was no doubt due to the belief that activity meant psycho-activity that was shown by THC and not by CBD. In retrospect, this was unfortunate since a number of actions of CBD with potential therapeutic benefit were downplayed for many years.

Cannabinoids are almost exclusively found in cannabis, and have been shown to have a significant effect on chronic skin conditions. Cannabinoids are well-known to play a role in regulating inflammation, and this may be the key to their ability to treat eczema and psoriasis.²

It is well-documented that the gastrointestinal tract, which, like the skin, is one of the primary physical barriers of the immune system, has abundant cannabinoid receptor sites. Now, research has shown that the skin also has an endocannabinoid system of its own, which helps to regulate the production of various hormones and proteins, including cytokine, which is also involved in the immune response.  The skin’s endocannabinoid system also helps to regulate various cellular processes including proliferation, differentiation, and apoptosis or cell death. Thus, imbalance of this system may also be responsible for the occurrence of chronic skin conditions such as psoriasis and eczema, and developing targeted cannabinoid therapies may help to control them.³

Human tissues have at least two types of cannabinoid receptors, CB1 and CB2, each coupled with a protein. CB1 receptors are expressed predominantly at nerve terminals where they mediate inhibition of neurotransmitter release. CB2 receptors are found mainly on immune cells, one of their roles being to modulate cytokine release. Endogenous ligands for these receptors, endocannabinoids, also exist, and examples include the molecule anandamide. These discoveries have led to the development of CB1- and CB2-selective agonists and antagonists and of bioassays for characterizing such ligands. So in the future we can have much more targeted cannabinoid therapies.⁴

Mauro Maccarrone’s Italian study demonstrated that human skin cells or keratinocytes are part of the peripheral endocannabinoid system and showed a unique signaling mechanism of CB1 receptors, which may have important implications in epidermal differentiation and skin development.⁵

A study published in 2007 demonstrated THC, CBD and the other cannabinoids CBN, CBG and anandamide all demonstrated some level of effectiveness in inhibiting the production of skin cells or keratinocytes in the top layer of the skin. Because over-production of keratinocytes is involved in psoriasis, these results should lead to further investigation into cannabinoid therapies to treat psoriasis. Cannabinoid receptors have been found in even the smallest nerve fibers controlling hair follicles, and keratinocytes have also been shown to bind and metabolize anandamide, the most abundant endocannabinoid.⁶

Wilkinson investigated the plant cannabinoids Δ-9 tetrahydrocannabinol (THC), cannabidiol, cannabinol and cannabigerol (CBG) for their ability to inhibit the proliferation of a hyper-proliferating human keratinocyte cell line and for any involvement of cannabinoid receptors.⁷

The results confirmed cannabinoids have a role in inhibiting keratinocyte proliferation, and therefore supported a potential role for cannabinoids in the treatment of psoriasis.

In other research, published in The Federation of American Societies for Experimental Biology (FASEB) Journal, it was shown that cannabinoids produce lipids that can regulate skin conditions such as acne vulgaris, seborrhea and dry skin. They suggested further exploration of cannabinoids as “novel therapeutic tools" to treat dry skin.

Another study took seven phytocannabinoids representative of the major structural types of classic cannabinoids and their corresponding cannabivarins and investigated them for topical anti-inflammatory activity in a mouse ear dermatitis assay. Results suggested that the involvement not only of cannabinoid receptors, but also of other inflammatory end-points targeted by phytocannabinoids, were important in the regulation of dermatitis in mice.⁸

In summary, we have many studies documenting the contributory nature of cannabinoids, their receptors, and the skin’s endocannabinoid system in the metabolism of psoriasis and eczema and other inflammatory diseases,⁹ of which aging of the skin is considered one. In the coming years there is great hope for the use of targeted cannabinoid therapies to better control these chronic skin changes. 

Jeanette Jacknin, M.D., is a board-certified dermatologist, author, national speaker and consultant with expertise in holistic dermatology and natural cosmeceuticals.

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