CBD Bioavailability: How To Harness The Power Of CBD
Date 27th Apr 2021
We all know that CBD supplements aren't cheap. There's a lot of costs involved in creating a high-quality CBD product, but how can we make the most out of our CBD oil?
Bioavailability determines how much of the active ingredients make it into your bloodstream to exert its effects. The bioavailability of CBD depends on your method of consumption and its potency.
For instance, a CBD gummy may have 25MG of CBD, but only a fraction of that 25MG actually enters the bloodstream. This is because our digestive system begins to break down CBD before it has a chance to enter the small intestines for absorption.
If there was some way to increase CBD's bioavailability rate, we wouldn't need as high of doses to reach our desired effects, improving CBD's overall cost-effectiveness. Luckily, CBD is an incredibly versatile compound with many different uses and methods of consumption — the innovation in this industry is only scratching the surface.
In this article, we'll get to the bottom of which CBD delivery method offers the highest bioavailability rate and recommend ways you can maximize your CBD.
What Is Bioavailability And Why Is It Important?
Bioavailability refers to the degree to which a substance becomes completely available for its intended action in the body. Improving the bioavailability of the compounds we supplement means less of that active ingredient is wasted. Poor absorption of a compound means we're not making the best use of it, and it can get expensive to reach the desired effects.
CBD and other cannabinoids primarily exert their effects on the endocannabinoid system (ECS). How CBD is absorbed depends largely on the route of administration and how much of it enters the bloodstream, where it's then transported throughout the body.
When it comes to the bioavailability of CBD, not all methods or products deliver the same results. There are several factors in the development of a CBD product that can either help or hinder the way our body absorbs CBD.
The most common discussion on the bioavailability of CBD is the delivery method. Let's go over some of the most popular options for CBD products on the market and raise some of the pros and cons of its practical uses.
Edible CBD Bioavailability: Capsules and Gummies
Oral consumption of CBD is perhaps the most popular delivery method. Although convenient, the oral bioavailability in CBD gummies, CBD capsules, and other edibles has the lowest average absorption rates from 13–19% in humans . That means up to 87% of your CBD is going un-used.
What happens to that significant chunk of the CBD we eat that doesn't make it into our bloodstream?
Stomach acids and enzymes begin to break down the active ingredients before we get a chance to absorb the CBD in the small intestines. The CBD that does make it through must enter the hepatic portal system. This is the series of veins that carry blood from the digestive system (stomach and intestines) to the capillaries in the liver where it's processed by the first-pass metabolism.
The first-pass metabolism or first-pass effect is when an active compound administered orally gets processed by the stomach then enters the liver, where it gets broken down further into its metabolites to be essentially discarded .
As you can see, the oral bioavailability of oral CBD is dismal as it succumbs to hostility in the stomach and liver processing.
How To Improve The Bioavailability Of Edible CBD
Have you ever wondered why some medication and vitamins have instructions to take your pills with a meal?
Eating your supplements with food is supposed to increase the bioavailability of the compound. The type of food you eat with CBD has been shown to affect its absorption rate, too.
The University of Minnesota conducted a study examining whether high-fat foods increased CBD's bioavailability and found promising results. Compared to fasting before consuming CBD, participants who took CBD with a meal increased the CBD measured in the blood up to 4 times . Why does this happen?
Cannabinoids are lipophilic molecules, in other words, fat-soluble compounds that don't dissolve well in water. This is problematic for absorption because our bodies are made up of up to 70% water.
One of the reasons you'll also find CBD Softgels mixed with a carrier oil (coconut oil, hemp seed oil, olive oil) is to increase the bioavailability. This is because the body is prepared to absorb fatty foods, which means CBD can hitch a ride on these fat molecules to avoid destruction by the first-pass metabolism.
Sublingual CBD Bioavailability: Tinctures, Oils, And Sprays
If you're looking to make the most of oral CBD supplementation (CBD oils, CBD Oral sprays), sublingual administration has a higher bioavailability and faster onset action when compared to edible CBD. Researchers found varying sublingual CBD absorption rates, but it's been observed to be as high as 35% .
The sublingual method of consuming CBD relies on the mucus membrane beneath the tongue that houses a circuit of micro-capillaries, where it can enter directly into the bloodstream.
Taking CBD and holding it beneath your tongue for 30-90 seconds allows the CBD drops to avoid the first-pass metabolism and digestive enzymes altogether. Since not all the liquid will get absorbed under your tongue, you'll swallow the rest.
Inhaled CBD Bioavailability: Vapes And Smokeables
Smoking CBD is the most efficient and fastest way to use CBD, but it's not for everyone. Smoking produces combustion byproducts that can irritate the lungs. Those with lung sensitivities and children should not inhale any CBD products.
The reason for CBD's fast-acting effects via the lungs is that it completely skips digestion and the first-pass metabolism through the lungs' oxygen-exchange pathway where it's absorbed into the bloodstream.
Burning hemp cigarettes does produce more combustion byproducts and is more irritating to the lungs than vaping. That being said, vaping is not completely without its risk for lung irritation.
Transdermal CBD Bioavailability: Topicals And Patches
Delivering CBD through the skin is another method of skipping the first-pass metabolism and it's minimally invasive and less irritating. However, human skin has low permeability because its principal job is to protect us from our environment.
CBD lotions, CBD rubs, and CBD massage oils all fall under the category of CBD topicals that lend their benefits to localized areas rather than exerting their effects throughout the body. This is because CBD applied topically does not enter the bloodstream.
Instead, topical CBD interacts with cannabinoid receptors in the epidermis to support skin wellness and discomfort.
Research on transdermal CBD application is limited. The technology behind slow-release patches is expensive, and it doesn't seem to yield any significant advantages for the bioavailability of CBD through the skin.
To increase the effectiveness of topical CBD products make sure there is a high enough concentration of CBD (at least 5 mg/mL) to make it through the skin barrier.
You may also want to consider other skin-nourishing ingredients like jojoba oil, shea butter, and essential oils that help to support skin wellness. To improve discomfort, natural heating or cooling and cooling additives like capsaicin extract from hot peppers or menthol can help to support relaxation.
Rectal CBD Bioavailability
Although it may sound unpleasant, there are reasons why someone may use CBD suppositories, including relief closer to the bowels and abdomen, or the person has no other practical method of absorbing CBD either because they can't swallow or they're on another medication that interferes with the absorption through the digestive system.
Rectally administered CBD has a high bioavailability rate between 25-50% .
The rectum receives blood supply from three arteries, which means the compounds enter the bloodstream bypassing the liver metabolism. CBD suppositories are usually oval or cone-shaped and include CBD infused in cocoa butter or coconut oil that melts quickly with body heat.
Intravenous CBD Bioavailability
Intravenous administration of CBD is not a common delivery method and is only limited to clinical use.
Injecting CBD into the bloodstream has 100% bioavailability and fast-acting, but it was also observed to break down faster than other delivery methods, which means it may not be the most effective method of using CBD . Ideally, you want the CBD to stay in your system for longer to support your endocannabinoid system's role in maintaining homeostasis in vital systems.
This observation shows us that while a method can have a high bioavailability, it doesn't necessarily mean it's the best way to take CBD.
What About CBD Marketing Claims To "Boost Bioavailability?"
The CBD industry is always looking to push the boundaries of how we consume CBD — one of which is nano CBD or sometimes called "water-soluble CBD" that's reported to increase the average bioavailability of oral CBD.
Nano-emulsion technology is one of those marketing terms that begs the question of whether or not it truly is more effective or if it's another marketing gimmick.
What exactly is Nano CBD? Nanotechnology is pervasive in the medical, cosmetics, and even robotics industry and it's the application of "extremely small things."
Cannabinoids are lipophilic molecules, which means they dissolve into fats, and they're hydrophobic. Remember, this is problematic for absorption as the human body is comprised of over 70% water. The goal of nanotechnology in CBD is to increase the bioavailability of CBD. Some companies call nano CBD "water-soluble CBD" — but this is a misleading term.
You cannot change the nature of CBD's solubility in water (read more in our post on CBD Bath Bombs). What they're essentially doing here is breaking down the CBD particles so they become so small (nano) that it appears to dissolve in water. These compounds still follow the fat absorption pathway. The only difference here is that the body can absorb particles better if it's broken down into smaller particles.
To further improve the rate of absorption, manufacturers encapsulate the nano CBD particles in a nano-structured lipid carrier (NLC). It's a fancy term for biodegradable and biocompatible fat and surfactant surrounding the nano CBD particles as the vehicle through which the CBD can pass through the digestive system. A study found that compared to regular CBD oil, the absorption of nano-emulsion CBD increased by 65% .
The research on nano CBD is quite limited, but it's showing some promising results for increasing the bioavailability of oral CBD. That being said, the term "nano CBD" is thrown around a lot in the CBD space and there's very little regulation on who can use that term, so as always do your due diligence when shopping with the brand to ensure they're conducting rigorous independent testing and are on the pulse on research in the nanotechnology CBD space.
Factors That Can Affect Bioavailability
Now that we've discussed external factors that can affect CBD's bioavailability, it's worth looking at some of the internal factors that may affect your use of CBD.
- Your State of Health: The liver plays a principal role in filtering substances we consume via our digestive system. The liver also metabolizes and eliminates CBD in our bloodstream. Health conditions relating to the liver may affect your CBD dose to reach your desired effects.
- Your Genetics:Your genetic profile can influence how fast your body metabolizes CBD. There is a genetic variant present in 25% of the population that can lead to a slower metabolism rate for processing CBD .
- Dose: You can affect how much CBD gets absorbed into your system by simply increasing your dose.
- Fasted State Vs Taken With Food: CBD absorption was found to increase when taken alongside food, especially high-fat meals, compared to an empty stomach.
The Takeaway: Bioavailability Of CBD
While CBD is becoming more and more widely available online and in many different products, we're still only beginning to understand how the body processes CBD. Of course, we're always looking to find ways to make the most of our hard-earned cash—and increasing the bioavailability of CBD is one way to do it.
It's important to keep in mind that your genetics, state of health, and method of consuming CBD all play into its efficacy in your system. If you plan on taking CBD to support a health condition, we recommend you speak to your health care professional for advice and they can best guide you towards your individual health goals.
For more articles like this relating to how to use CBD and its benefits, you can check out our blog.
- Xu, C., Chang, T., Du, Y., Yu, C., Tan, X., & Li, X. (2019). Pharmacokinetics of oral and intravenous cannabidiol and its antidepressant-like effects in chronic mild stress mouse model. Environmental toxicology and pharmacology, 70, 103202.
- Robertson, D. (2017). First pass metabolism. Nurse Prescribing, 15(6), 303-305.
- Birnbaum, A. K., Karanam, A., Marino, S. E., Barkley, C. M., Remmel, R. P., Roslawski, M., ... & Leppik, I. E. (2019). Food effect on pharmacokinetics of cannabidiol oral capsules in adult patients with refractory epilepsy. Epilepsia, 60(8), 1586-1592.
- Millar, S. A., Stone, N. L., Yates, A. S., & O'sullivan, S. E. (2018). A systematic review on the pharmacokinetics of cannabidiol in humans. Frontiers in pharmacology, 9, 1365.
- Paudel, K. S., Hammell, D. C., Agu, R. U., Valiveti, S., & Stinchcomb, A. L. (2010). Cannabidiol bioavailability after nasal and transdermal application: effect of permeation enhancers. Drug development and industrial pharmacy, 36(9), 1088-1097.
- Huestis, M. A. (2007). Human cannabinoid pharmacokinetics. Chemistry & biodiversity, 4(8), 1770.
- Brenneisen, R., Egli, A., Elsohly, M. A., Henn, V., & Spiess, Y. (1996). The effect of orally and rectally administered delta 9-tetrahydrocannabinol on spasticity: a pilot study with 2 patients. International journal of clinical pharmacology and therapeutics, 34(10), 446-452.
- Meyer, P., Langos, M., & Brenneisen, R. (2018). Human pharmacokinetics and adverse effects of pulmonary and intravenous THC-CBD formulations. Medical Cannabis and Cannabinoids, 1(1), 36-43.
- Nakano, Y., Tajima, M., Sugiyama, E., Sato, V. H., & Sato, H. (2019). Development of a novel nanoemulsion formulation to improve intestinal absorption of cannabidiol. Medical Cannabis and Cannabinoids, 2(1), 35-42.
- Iffland, K., & Grotenhermen, F. (2017). An update on safety and side effects of cannabidiol: a review of clinical data and relevant animal studies. Cannabis and cannabinoid research, 2(1), 139-154.