Cannabis, Cannabinoids and CBD
by Claudia S. Copeland, Ph.D.
For thousands of years, cannabis was valued as a broad-spectrum herbal medicine. Despite decades of suppression by U.S. drug prohibition in the 20th Century, it is clear today that the old-time physicians were right: cannabis has diverse uses in medicine and health. Patients have found it to be helpful for a broad spectrum of medical conditions, including cancer, ADHD, glaucoma and pain.
Of the more than 100 cannabinoids found in the cannabis plant, tetrahydrocannabinol (THC) has been the most widely studied. A synthetic version of THC — marketed under the name Marinol — has been found to be a highly effective treatment for the nausea and vomiting associated with cancer therapy. Use of “medical marijuana” for that purpose was the first to receive legal approval. Unfortunately, this cannabinoid remains illegal in many places unless in the form of prescription pills like Marinol.
However, cannabidiol (CBD), second only to THC in medicinal applications, is perfectly legal. CBD can act as a potent anxiolytic, anti-epileptic, antipsychotic or neuroprotective agent, through its anti-inflammatory and antioxidant properties. Several other cannabinoids, including cannabigerol (CBG), Δ9-tetrahydrocannabivarin (Δ9-THCV) and cannabidivarin (CBDV), can also be helpful, especially for neuropsychological disorders.
Because THC-containing products remain illegal in many places, all traces of THC must be removed from the cannabis plant from which CBD and other cannabinoids are harvested to produce over-the-counter medicines. In addition, patients have different needs and preferences: They may want only one specific cannabinoid or they may want as broad a spectrum of cannabinoids as possible. THC-free cannabinoid preparations are therefore available in different formulations. The formulations you’re most likely to see are CBD isolate, CBD distillate and full- or broad-spectrum CBD.
CBD isolate is pure CBD. This preparation has gone through multiple processes of filtration and isolation after extraction from the cannabis plant, so THC, all other cannabinoids and all other plant matter have been removed.
The advantage of taking CBD isolate is its purity. If CBD is the only compound you want in your medicine, CBD isolate is what you’re looking for. There are no contaminants and no extra compounds that might have different effects from the CBD itself.
The disadvantage of CBD isolate is that you will miss out on the effects of other compounds present in the cannabis plant. Cannabinoids and compounds, such as terpenes, flavonoids and fatty acids, have properties of their own — including flavor — that might be desirable. In addition, some people seek a phenomenon known as the entourage effect, in which other cannabinoids and botanical compounds present in the cannabis plant are thought to work together with CBD to enhance its efficacy.
Just as brandy and whiskey are distilled from fermented grapes or grain, CBD can be distilled from cannabis plant material. While precise instruction on how to make CBD distillate is beyond the scope of this article, the essence of the process is similar to distillation of any other substance: an extract from cannabis plant material is heated to the point of vaporization and then slowly cooled, allowing the collection of different fractions of the extract that are separated according to boiling point. The different compounds in cannabis have their own specific boiling points and therefore will condense at different temperatures. Substances with high boiling points will condense first; when they do, that fraction of the extract can be collected. When the temperature is lowered further, substances with lower boiling points will condense; that fraction can then be collected in a separate container. This yields fractions separated on the basis of boiling points. Efficiency can be improved by employing various technological approaches; for example, distilling in a vacuum. Highly sophisticated methods and equipment can be employed for precise distillation, but their core essence remains the same as the old prohibition-era stills — boil, cool slowly and collect the fractions that condense at different temperatures.
The difference in boiling point between CBD and THC is often considered to be around between 20 degrees and 40 degrees Celsius (68 degrees to 104 degrees Fahrenheit). That would be far enough apart to allow distillation of a CBD-containing fraction that is virtually free of THC; that is to say, approximately pure CBD. However, some experimental methods have found the difference in boiling point between THC and CBD to be as narrow as 5 degrees Celsius. What this means is that depending on the distillation protocol, it is possible that some THC as well as other compounds will remain present in CBD distillate. Again, if you want absolutely pure CBD, the product to buy is CBD isolate.
Plants emit a number of compounds that are beneficial, and we often have only a vague understanding of how they exert these effects. The documented health benefits of the Japanese practice of forest bathing, for example, are thought to be at least partially due to the broad array of volatile organic compounds emitted by the diverse plants in a forest. It would take decades of research to understand the effects of all of these botanical compounds.
Furthermore, it has been proposed that exposure to a diversity of compounds can increase the benefits of exposure to a single, targeted compound — a phenomenon known as synergy. In cannabis, this phenomenon of diverse compounds working together synergistically is known as the entourage effect, and it is thought by many users to enhance the effectiveness of CBD.
Considering cannabis’s long-standing historic use as a broad-spectrum medicine, many people would like an extract with all of the components present except for THC (which must be removed for legal reasons or to prevent the psychoactive effects, which can impair life functioning). The term “full-spectrum” is generally used to refer to such an extract; specifically, an extract that contains all of the cannabinoids, but less than 0.3 percent THC, which is the maximum amount allowed by Federal law in CBD products. This type of extract can be achieved by starting with a low-THC hemp plant rather than a high-THC marijuana cultivar.
Some people want a broad spectrum of cannabinoids but must have absolutely no THC in the mix — not even trace amounts that will cause no psychoactive effects — for reasons of drug testing, for example. An extract from which the THC fraction has been actively removed using techniques such as chromatography or distillation and that contains all of the cannabinoids except THC would more accurately be called “broad spectrum.” If distillation is used, but all of the fractions except the THC-containing fractions are mixed back together, the resulting product is often called “full-spectrum CBD distillate”.
Deciding Which CBD Product Is Right for You
Depending on your point of view, the additional effects of a spectrum of cannabinoids and other botanical compounds can be seen as added benefits or unwanted side effects. When deciding which type of CBD product to purchase, consider your purpose and requirements. If you want to explore an option for treating a little-studied health condition, you will probably want to go with a full-spectrum product so you can get the benefit of all of the cannabinoids. If you want to purchase CBD for a child with epilepsy, you’ll probably want to stick with CBD isolate so that your growing child won’t be taking anything besides the CBD itself. No one product is best for everyone and all purposes; put some thought into your specific needs before making a decision. Finally, speaking with a cannabis-friendly physician is the best way to get insight about the ideal product for your unique medical goals.