Fashions come and go in the cosmetics and personal care world, and everyone is keen to be on the latest trend as soon as possible. The latest buzzy thing seems to be Cannabidiol or CBD. This has an interesting background, being a derivative of hemp which is also the source of cannabis – which has been a popular if illegal recreational pharmaceutical since the sixties. So CBD comes with ready made notoriety. But it is currently being sold not as a gateway into a counter culture, or even as an aid to relaxation, but as a substance with health benefits.Just to get it out of the way, there is nothing illegal about CBD. It doesn’t have any of the psycho-active properties of the cannabis resin traded on the street and can be bought and sold freely without troubling the law enforcement fraternity.
Scientifically speaking it is what biologists often refer to as a secondary metabolite. Every plant produces a set of primary metabolites – these are the proteins, carbohydrates and fats it needs to maintain its energy supplies, preserve its structure and hold all the information it needs to produce new plants. In addition to this basic housekeeping many plants also produce secondary metabolites that have other more complex roles than simple survival, and which are often responses to the environment in which the plant lives. A good example of that is the pungent oil that the rosemary bush produces. This puts grazing animals off the idea of eating it.
The production of rosemary oil is in fact very dependent on how the bush is grown. The best oil comes from bushes in the hot and dry climate of southern Spain. The one that grows in my garden in the wet and cloudy UK doesn’t really have the same punch. But there aren’t so many hungry goats around here.
Secondary metabolites can be very serious propositions. The foxglove produces a poison called digitalis that is quite powerful enough to be deadly to an adult human. In fact it is also used as a treatment for heart attacks, but only when the quantities are carefully managed by pharmacists and prescribed with care by doctors. The yield of digitalis, like that of rosemary oil, is affected by the climate. The foxglove has limited resources and doesn’t produce secondary metabolites unless it really needs to. The most remarkable example of secondary metabolite production to my mind is a species of red clover in Australis that produces a substance that causes sheep that graze it to abort. There seems to be a feedback mechanism whereby more of the agent is produced the heavier the grazing.
So it is not at all surprising to find secondary metabolites having biological effects, and these can include positive and negative health effects on human beings. This is something to bear in mind when using essential oils, which are effectively secondary metabolites. These have been used in aromatherapy for many years now and they have proved to be pretty safe overall. But this is not something that should be assumed just because they are natural. Although the present palette of oils that we work with has proved itself to be acceptable, any novel ones that people come up may not fall into the same pattern. If foxgloves weren’t so well known we might even now not be aware how poisonous they are. Being natural is no guarantee of being safe.
So when a secondary metabolite like CBD appears on the scene a bit of caution is in order. When it starts getting touted as a cure for some medical conditions, then there is even more reason to be careful. There is every reason to believe that this material might be active. And on the whole, you don’t get positive effects without some negative ones along with them. Even very safe drugs like Nurofen often turn out to do some things we’d rather they didn’t.
So let’s have a look at CBD. What is claimed for it? What’s the evidence behind those claims? And what are the potential dangers? In fact there are quite a few claims, including mood altering ones such as tackling anxiety that seem to mirror what is often said about cannabis. These kinds of claims are difficult to pin down and to prove, and are often hard to separate from the power of suggestion. In fact I wouldn’t knock the power of suggestion – it’s quite a powerful and real effect. If it is working in your favour, well why not? But more specific effects are easier to get a handle on so lets focus on them.
It is claimed to have an anti-cancer effect. This seems to be reasonably well founded in that there is evidence that it works, with the caveat that it doesn’t seem to have been tried all that widely yet. Likewise, for epilepsy there have been some promising results but nothing like a clear demonstration of it working better than a placebo. Its best data is for treatment of pain. That is probably the most interesting claim from a skincare product perspective.
It takes time for a treatment to become established, and if CBD is going to become a mainstream first line option for these conditions it will have to go through a phase where its benefits are being fully evaluated. We could be at that stage now and maybe in 10 years time it will have become a regular feature on your local pharmacy’s shelves. Or maybe it won’t live up to the early indications and will fade away. Or maybe some drawback will come to light that limits its use. Nobody really knows so we’ll just have to wait and see.
Safety is in much the same place as efficacy. There is not much indication of it being a problem and it is probably safe enough. But you can’t rule out complications emerging if it starts to get used more widely. There have been a couple of specific toxicology studies that had positive results. And there have been clinical studies that while they aren’t looking at safety, do involve the material being used under medical supervision. So if they don’t reveal a problem, that is encouraging. But if something has biological activity you have to stay on guard in case something unexpected turns up.
But in the meantime, it is only a matter of time before it starts getting widely used in personal care products. No bandwagon this tempting could possibly be ignored. Indeed there is already a thriving market in cosmetics containing hemp oil. The Body Shop went big with hemp oil around the turn of the century, and they still sell most of the range that they launched and heavily promoted back then. Hemp oil will contain at least some CBD, along with other related molecules. The new twist, which is already being done by some small specialist brands, is to use CBD itself and to claim pain relief – usually with some other claims. It’s only a matter of time before someone with pockets deep enough to do it properly launches a CBD pain relief product aimed at the mass market and backed up with an explicit promotional campaign. This could just as easily be an existing player or a new entrant.
It will be interesting to see how the marketers handle the material’s heritage. Will they embrace its hippy past or try and work with a more scientific approach? And pain relief is not strictly speaking a cosmetic claim, so the wording will have to be very careful not to trigger the interest of the medicines authorities.
It will also be interesting to see how formulators respond to its challenges. It is something that might be expected to penetrate the skin, but perhaps rather slowly. We don’t actually know if it will work applied topically yet, but lets assume it will. So the challenge might well come down to coming up with a formulation that enhances skin penetration. This is one of the trickier problems in skincare. The skin is a pretty good barrier and keeps most things out very effectively. I also wonder if pure CBD oil will in any case turn out to be the best way of delivering pain relief. These kinds of thing often work better with a mixture of related molecules than with a single one. Nobody really knows why, but my guess is that different sizes and shapes of molecules move at different speeds, so they arrive at different times giving a more sustained effect. It might well turn out that breeding CBD rich varieties of hemp oil proves a better approach than adding purified CBD oil on its own.
Final question – will it become a successful skincare active? Things that work usually gain a following and the indications are that this might well be effective. I think that while we are all swayed by advertising to some extent, you don’t get resales if the consumers don’t get some kin of payback. If CBD overcomes pain it should win over long term customers. It is also supposed to have anti-inflammatory properties as well, and that is another possible benefit. I think that skincare use is only semi-conscious after a while. You might not give it a lot of thought but if it makes you feel better you stick with it. So I won’t be surprised if in 10 years time long after the fuss has died down there might be a CBD brand that has an established following.
(Note that this paper has been peer reviewed, but nonetheless originates from a company with an interest in the commercial exploitation of CBD oil.)
JAMA. 2015 Jun 23-30;313(24):2456-73. Cannabinoids for Medical Use: A Systematic Review and Meta-analysis. Whiting PF, Wolff RF, Deshpande S, Di Nisio M, Duffy S, Hernandez AV, Keurentjes JC5, Lang S, Misso K, Ryder S, Schmidlkofer S, Westwood M, Kleijnen J.