Cannabis, cannabinoids, and your skin

November 25, 2019 / Duncan Fisher
New treatments are emerging, but they’re not ready.

So, you can buy bedsheets laced with ‘CBD’, and sleeping in these sheets will ease your eczema.

Or so says catalogue copy that you can find easily on the internet.

But is this health claim true? And what’s CBD, you may ask? Isn’t that part of the medical marijuana discussion? And if CBD is good for you, wouldn’t smoking marijuana also be good? What are all these weed derivatives? And will they really be medicine someday? For your skin?

Cannabinoids are complicated

First of all, know that physicians and pharmacologists have moved past talking about ‘medical marijuana.’ Nobody seriously thinks the right intervention for anyone's medical ailment is to have them smoke weed. One of the ingredients, called ‘delta-9 tetrahydrocannabinol’, or ‘THC’, is psychoactive, and causes problems, particularly in young and growing brains. Smoking, as a delivery system, causes trouble too, in your lungs (and your skin) and elsewhere.

But other ingredients, other ‘cannabinoid’ molecules, do show promise, in a surprising range of medical maladies. Data is accumulating about how they may be of help, for example, in certain kinds of pain (though not other kinds), certain neurological syndromes, some forms of dementia, and a range of psychiatric disorders.

And our knowledge base is accelerating. Cannabinoids are getting easier to study, because we’re losing our horror of cannabis as counterculture, and because there’s a lot of good money to made out of genuine pharmaceuticals. Professional research is underway quite widely now, pharmaceutical companies are tooling up for large-scale production, and regulation is relaxing to allow all this.

Remember, though, that clinical trials move slowly, because molecular biology is complicated, and subtle, and being thorough with it takes time. Also know that we’re actually talking about 3 different kinds of cannabinoid here: ‘phytocannabinoids’, that grow in the ground, ‘endocannabinoids’, that you manufacture yourself (yes, in your body, and you have an endo-opioid system too – think endorphins, and ‘runner’s high’), and synthetic cannabinoid molecules, that are made in labs. All three of these bind to one or both of a pair of neuro-receptor sites, most of them in your brain, spoken of usually as ‘CB1’ and ‘CB2’, and from there they do their work with downstream enzymes, generally in a dose-dependent manner. How they do this varies a lot, and is galactically complicated.

Cannabinoids in dermatology

Here’s what’s current in the research, paraphrased.

Acne

In acne, there is evidence that several cannabinoids can lower sebum production, and reduce erythema, or inflammatory reddening.

Allergic contact dermatitis

Several synthetic cannabinoids, acting at the CB2 receptor, have mediated allergic inflammation in experimental mice.

Eczema

Two cannabinoids have produced better hydration in skin with ‘asteatotic’ eczema, a drying-out, non-atopic form of eczema common in older people. Several others have shown complex action in atopic eczema resulting in dramatic reduction of symptoms, particularly itching.

Pruritus, or itching

Itching is probably the most promising dermatological application of cannabinoid derivatives. CB1 and CB2 are known to function in reducing action in sensory nerve fibers, mast cells, and keratinocytes. There is real promise in topical treatment for the discomfort associated with atopic dermatitis, lichen simplex, prurigo nodularis, and uremic pruritus.

Hidradenitis suppurativa

This is a painful condition that causes abscesses and scarring on the skin. Some cannabinoids may ease this, by inhibiting the release of calcitonin gene-related peptide.

Psoriasis

There are cannabinoids that pretty clearly help in psoriasis, by slowing proliferation of keratinocytes, helping acetylcholine release, and down-regulating the immune response that causes the painful symptoms of psoriasis.

Skin cancer

Melanoma and non-melanoma cancer cells both express the CB1 and CB2 receptors. Activating these sites has been shown in laboratory trials in test tubes to slow tumor growth, particularly in melanoma. There is reason to think that at least one cannabinoid may also slow progression of Kaposi sarcoma, a rare, virus-driven cancer in skin.

The skin verdict

This does not mean that smoking dope is good for you.

But handled right, some extracted cannabinoids are very promising, in dermatology and elsewhere. So are some cannabinoid-like molecules – you’ll hear them called ‘terpenes’ – that some people advocate as food additives.

Not enough is known yet for routine clinical use, however. There are dozens of cannabinoids that need testing. And their actions are enormously complex, and at this point barely understood. Also, in experimental trials, cannabinoids have caused some undesirable, and sometimes dangerous, side effects. Cannabinoids as medication, in other words, is not a field for amateurs.

Back to those bedsheets. Should you buy them? CBD is cannabidiol, which is benign enough to be allowed for sale in low concentrations in health food shops in Europe these days. It is known to be an anti-oxidant and anti-inflammatory compound in skin. It’s a natural phytocannabinoid, that isn’t psychoactive.

Will CBD in your bedding help your itchy skin? Before you buy, look for trial data that suggests that it will. Also, think slowly about mechanisms of action, and the likelihood that it can actually work.

Or buy the sheets and try them.

Better yet, have a talk with your dermatologist. That’s the very best way to approach cannabinoids for your skin. It is a very interesting new field, and full of promise – but it’s not simple.

Questions about your skin? Ask our dermatologists online for $35.