Thanks largely to legal changes introduced by the 2018 Farm Bill, cannabidiol (CBD) has become an increasingly common fixture in medicine cabinets and on the shelves of local convenience stores and major drugstores.
The cannabis species naturally produces hundreds of active compounds. CBD is a chemical compound produced in abundance that has become one of the most commonly sought after cannabinoids. This is largely due to the potential medical and wellness benefits of CBD.
As CBD becomes more well known, there is growing awareness that not all CBD products are made the same, nor are they even necessarily derived from the same kind of cannabis plant.
CBD comes from one of two types of cannabis plant: hemp or marijuana.
Hemp-derived oil and CBD products are sourced from industrial hemp plants, which are grown primarily for their fiber andseeds. These plants tend to differ from marijuana plants in appearance; they are often skinny and have sparse foliage. Hemp is also differentiated from marijuana by its levels of tetrahydrocannabinol (THC), the cannabinoid that causes consumers to feel “high.”. As outlined in the 2018 Farm Bill, a hemp plant must contain no more than 0.3% THC.
Marijuana-derived CBD is extracted from cannabis plants that have thick, lush foliage and flowers that are generally grown and consumed for their intoxicating properties. US law defines marijuana as cannabis plants that contain more than 0.3% THC. While THC is the predominant cannabinoid in most weed plants, several strains of marijuana are rich in CBD.
That being said, whether CBD is extracted from hemp or marijuana, it remains identical on a molecular level.
“The CBD molecule and its associated pharmacology are the same, whether it was extracted from hemp or from marijuana. CBD is CBD, regardless of where it was originally derived from,” explained Jeremy Riggle, Ph.D, chief scientist at Mary's Medicinals, a medical cannabis company known for its Transdermal Cannabis Patch.
Despite the identical molecular constitution of CBD sourced from hemp and CBD sourced from marijuana, there are certain factors that differentiate CBD sourced from the two plants.
When discussing marijuana-derived vs. hemp-derived CBD oil, it is helpful to go through some basic cannabis taxonomy to better understand the cannabis plant.
The cannabis species is generally broken down into three main types: cannabis sativa, cannabis indica, and hemp. The cannabis sativa plant contains THC and a wide variety of cannabinoids and terpenes and is typically a taller, thinner plant. The cannabis indica plant is also full of cannabinoids and terpenes but is typically a shorter, bushier plant.
Finally, as outlined above, hemp plants are legally defined as cannabis plants with less than 0.3% THC. Despite these very low levels of THC, these plants still produce a broad range of cannabinoids and terpenes. These plants are typically grown for industrial uses and for other legal products.
What follows are some of the key differences between using hemp vs. marijuana plants to extract CBD and to make CBD oil.
One important aspect to understand when considering the difference between hemp-derived CBD and marijuana-derived CBD is the resin content of each plant. Cannabis resin is found within the trichomes of the plant.
Cannabis buds and, to a lesser extent, leaves usually contain copious amounts of resin, while industrial plants contain significantly less. So it follows that marijuana offers a more abundant source of CBD than hemp. A much larger quantity of plant material is needed to extract the same amount of CBD oil from hemp as from marijuana.
There is an exception to this rule. Some emerging craft hemp varieties possess unusually high concentrations of CBD, such as Cherry Charlotte, Cobbler, and Berry Blossom. These cultivars contain between 12% and 20% CBD with 0.3% THC or less.
Isolate vs. full-spectrum CBD
CBD isolate products are those which contain only the CBD molecule, with no accompanying terpenes, THC, or other cannabinoids. For patients with certain medical conditions, or those wishing to avoid THC, CBD isolate may be preferred. The alternatives to CBD isolate would be whole-plant CBD oil, full-spectrum CBD oil, or broad-spectrum CBD oil.
“Full-spectrum [CBD oil] is the extraction of all of the components — cannabinoids, terpenes, flavonoids, etc. — of the hemp plant including low levels of THC,” explained Dr. Chanda Macias, CEO of Women Grow, an organization connecting female professionals in the cannabis industry; and CEO of National Holistic, a healing center based in Washington, D.C.
Marijuana, on the other hand, tends to contain a more diverse terpene profile than hemp. Products derived from weed plants also tend to contain both CBD and THC in levels higher than 0.3%.
The entourage effect
Research indicates that full-spectrum CBD, whether extracted from hemp or marijuana, may offer enhanced therapeutic benefits.
“The entourage effect is essentially the synergy, in terms of outcome, that has been observed when cannabinoids are combined with other minor cannabinoids and terpenes,” Riggle said. “The combined effect is more pronounced in combination than in isolation, helping to prolong or enhance the overall effects.”
According to some wellness professionals and trustworthy health information sourced from a number of peer-reviewed studies, the entourage effect could help increase the clinical efficacy of CBD. One meta-analysis paper, published in September 2018, demonstrated that epileptic patients responded better to CBD-rich cannabis extracts that were complemented with various cannabinoids and phytonutrients.
One of the study's authors, Fabricio Pamplona, Ph.D, observed, “It's not necessarily always present in every clinical indication, but we observed that the patients reported lower doses with full-spectrum CBD than with pure/isolated CBD.”
Patients taking CBD-rich cannabis extracts also experienced fewer side effects. “It's a complicated system that is not yet entirely understood, but the current evidence suggests there is definitely an entourage effect when cannabinoids are combined either with other cannabinoids or with terpenes,” Riggle added.
Hemp seed oil vs. CBD oil
The terminology used to describe different products is the source of a lot of the potential confusion in the world of CBD oil. For example, while you might see labels that use the word hemp to indicate that the CBD came from a legal hemp plant rather than a marijuana plant, there is also a totally separate product called hemp seed oil.
While hemp-based CBD oils are all about delivering CBD and other cannabinoids or terpenes, hemp seed oil is not. Rather than coming from the leaves and flowers of hemp, hemp seed oil comes from the hemp seeds only and contains no CBD. Because hemp seeds are high in essential fatty acids such as gamma-linolenic acid and other nutrients, hemp seed oil has its own health benefits, which are different from CBD-rich hemp oil.
Hemp seed oil is generally used as a health and wellness dietary supplement that could give consumers many positive health benefits. Hemp seed oil can typically be found in health food stores, organic stores, and some regular grocery stores.
To break it down: hemp seed oil and hemp-derived CBD oil both come from the same plant and they both have potential health benefits. However, hemp seed oil comes from the hemp seed only and does not have any cannabinoids. Hemp-derived CBD oil is extracted from leaves and buds with the clear purpose of delivering CBD.
Which to choose? Experts weigh in
The law is one significant consideration that influences consumer choice between hemp- or marijuana-based CBD goods. Following the passage of the 2018 Farm Bill, industrial hemp was removed from the government's list of controlled substances.
The Farm Bill essentially introduced strict sourcing guidelines that hinge on the THC content of the plant matter being used in the extraction process. As a result, hemp became legal nationwide. Though most states still regulate CBD products to varying degrees, hemp-derived CBD oil is available. In contrast, marijuana-derived products can only be purchased in states where medical or adult-use cannabis has been legalized.
For those who have the freedom to choose the plant source of their CBD, the experts tend to highlight the benefits of choosing whole-plant products when possible, whether that whole plant is hemp or marijuana.
“I treat patients with both hemp and marijuana CBD products and I couldn't say one is more effective than the other. I can concur that most of my patients find that having THC, even the 0.3% found in hemp-derived CBD products, is more effective than products with 0% THC,” Damas said.
Similarly, Macias pointed out that there are medical conditions that respond only to CBD with varying levels of THC, while other conditions do not require the use of THC to achieve medicinal effects.
“Full-spectrum hemp can provide an entourage effect. The medicinal benefits of a hemp-derived entourage effect will depend on the medical condition, stage of the condition, patient physiology, and the dose response,” she explained. “I do believe, however, that CBD-rich marijuana extracts offer greater therapeutic value than full-spectrum hemp CBD, as it pertains to specific medical conditions.”
Experimenting with both hemp-derived and marijuana-derived CBD with varying levels of THC and CBD, if it's legal for you to do so, may be the key to finding the right product for your needs. Ideally, choose an organic product with a low CBD concentration and incrementally increase your intake or product concentration until you find a level that works for you.
“At this point, what we know about cannabinoid therapy is that it is highly individualistic and depends to a significant extent on the symptoms being treated,” Riggle said. “The clinical data is not there yet to provide a one-size-fits-all answer to this question.”
A word on contamination
Where and how the CBD is sourced has a major effect on contamination levels. A lack of stringent local regulations surrounding the production and refinement of hemp can lead to highly contaminated final products.
For instance, in China there are few regulations enforced on the agricultural industry, leading to the production of hemp-based CBD products that tend to contain high levels of contaminants. Studies have shown that, due to the country's mining activities, the water and soil in some regions of China are contaminated with heavy metals.
These contaminants manifest as toxins within hemp that can potentially taint CBD oil sourced from these plants. In order to remove the risk of ingesting contaminated CBD, it is safer to consume hemp-based products that are grown without chemical pesticides, and tested by a third party.
Major contributions from Dr. Adie Rae.