CBD Bioavailability: Part 2 of 2


by Mark Rosenfeld -

Editor's Note: This blog is the second installment of a two-part series on the bioavailability of cannabidiol (CBD). To read part one, click the following link: Measuring the Bioavailabilty of CBD.

When considering cannabidiol (CBD), oral and topical product offerings claiming "100 percent bioavailability" are not only a sham, but also an impossibility. First, only intravenous (IV) administration involves no target substance loss. Second, the other ways for getting cannabinoids into the body involve some sort of degradation and other metabolic obstacles.

Compared with the amount consumed or applied, less always reaches the bloodstream. As such, claims of "100 percent bioavailability" for oral or topical products are predicated on mistaken, ignorant and even fraudulent premises, for which valid supporting data will always prove nonexistent.

Bioavailability—Hemp vs. Marijuana

Some purport that marijuana trumps hemp in terms of bioavailability. Marijuana and hemp come from the same plant, Cannabis sativa. Each typically has CBD, but differs by levels of the psychoactive cannabinoid, tetrahydrocannabinol (THC). Hemp is C. sativa with 0.3 percent or less by law in dried plant material, an amount too low to get anyone "high." In contrast, marijuana has 25 percent and sometimes more.

In any case, cannabinoid molecular structures are the same, regardless of whether they come from hemp or marijuana. A bottom line for a purified cannabinoid is that there are no differences in performance irrespective of origin.

There are numerous genetic strains of both hemp and marijuana, and their chemical contents tremendously differ. Indeed, each contains not only cannabinoids, but also myriad terpenes, phytosterols, alkaloids, flavonoids and more than 1,500 additional plant-derived substances.

As a consequence, tremendous differences in bioavailability inherently exist among the many cannabinoid products that have been extracted and concentrated (most often with supercritical carbon dioxide) but not purified.

Even with the same plant strain, circumstances become further complicated by differences in growing conditions from one place to another. These result in plants with dissimilar chemical compositions, and thus divergent bioavailabilities.

True Bioavailability: Beyond the Bloodstream

Efficiently reaching the bloodstream might be an initial indicator of product performance, but the buck stops at true bioavailability or performance, the degree to which a substance impacts its target. For cannabinoids, the target is not just the bloodstream—but instead, select locations within the body; specifically, receptors on the outer surfaces of special cells:

1. A certain receptor binds only with a particular substance, e.g., a cannabinoid-like CBD, THC or cannabigerol. This binding initiates specific chemical responses inside the cell that may have profound consequences to health.

2. Most cannabinoids attach to "endocannabinoid" receptors CB1 and CB2 in the brain, spinal cord, spleen, immune system, endocrine glands (those glands that make hormones to regulate growth and development, sexual function, sleep, mood and more), reproductive system, intestines and urinary tracts.

3. CBD exceptionally does not, and instead has its own receptors. These are important for alleviating pain and reducing inflammation. CBD attaching to one receptor, GPR55, may be the foundation for a successful obesity therapy.

4. Besides the profound effects associated with CBD's receptors, this substance also has an indirect impact on the CB1 receptor—by helping promote the buildup of anandamide. Made in the body, anandamide binds to and is the primary regulator of the CB1 receptor. Higher levels of anandamide can desirably impact memory, motivation, speech and more.

It is important to recognize that different formulations containing the same active ingredient, once in the bloodstream, can have unequal true bioavailability. Some will yield more desirable responses than others. How consumers should evaluate this phenomenon is a matter for future discussion.

Mark J. Rosenfeld, Ph.D., is CEO and chief science officer at ANANDA Scientific Inc. He has centered much of his professional attention on making cannabinoids acceptable human medicine. Rosenfeld conceived and has directed the successful development of unique nanotechnologies to resolve unmet needs that have barred cannabinoids from widespread use to benefit human health. He holds 15 patents in pharmacology and molecular disease detection. ANANDA Scientific’s science-based approach spans research, development and production. The company has a strong presence in Israel—the global center for cannabis-related research—as well as China, with product production done in the United States.