Author: Luke Sholl
Put simply—bioavailability is the rate at (and extent to) which active ingredients reach their target area in the body. In this case, the active ingredient is CBD, and the target area is the bloodstream. If you wanted to ensure 100% bioavailability, the most direct method would be an intravenous dose of CBD.
However, intravenously administering CBD is not possible (except in very specific instances), advisable, or realistic. Instead, we can look at the estimated bioavailability of other, more conventional administration methods.
Perhaps the simplest explanation of bioavailability is to imagine your daily commute. On the way to work, most people try to take the most direct route. Not only is it the fastest, but it means you can get to work feeling refreshed and ready. An intravenous dose of CBD is the quickest route to work—no diversions or traffic, just a clear run.
However, for every set of traffic lights, roadwork, or diversions introduced, your journey takes longer and longer. And with each delay, you start to lose the enthusiasm you woke up with—well, the same principle applies to bioavailability.
For every obstacle introduced (digestive enzymes, stomach acid, rate of metabolism), the rate at, and therefore extent to, which CBD reaches our bloodstream is compromised. What starts as a high dose is slowly diminished as it travels through the body, just like your enthusiasm for work as you sit in traffic!
The reality is that although a drop of CBD oil may contain 2mg of CBD, for example, a smaller amount of that dose reaches the bloodstream. Therefore, the intensity and effectiveness of CBD oil hinge greatly on bioavailability. However, don't think taking CBD via one of the methods listed below is a waste of time. On the contrary, even a small amount, at a lower bioavailability, can still make a significant difference to well-being.
At present, you can find CBD in topicals, capsules, tinctures, edibles, vape liquids, suppositories, and nasal sprays. A diverse selection of products means that there's several ways to take CBD, each with unique benefits. However, alongside these benefits, each consumption method has a varying rate of bioavailability.
Oral consumption of CBD is the most popular option. However, once consumed, the compound has to contend with several biological processes before it reaches our bloodstream. The digestive system and its enzymes will do their best to dilute the dose of CBD you consume.
Due to the number of variables, it is almost impossible to give an exact expectation of oral bioavailability, but scientists believe it to be around 4–20%. It's not a terrible way to consume CBD by any means, but there are methods with greater bioavailability.
Although a very similar process to oral consumption of CBD, sublingual administration relies on the capillaries beneath the tongue for faster access to the bloodstream. By placing a few drops underneath the tongue, and holding them there for around a minute, sublingual CBD offers greater bioavailability than oral administration, although the exact improvement rate is under review.
According to anecdotal accounts, sublingually dosing CBD is a simple and effective way to increase its onset. Because it doesn't have to contend with the liver and GI tract, CBD should reach the bloodstream faster.
CBD-infused creams have the lowest bioavailability (5–10%) of all four administration methods listed here. However, this isn't necessarily a poor return on investment. The beauty of CBD topicals is that you administer them directly to the skin so the cannabinoid can provide benefits on a cellular level. Although CBD may not travel around the body or reach the bloodstream, it can still prove highly effective on a localised level (on the areas where you apply it).
By vaporizing, of course, we mean inhaling the vapor from vape liquids, which you heat to provide an instant hit of CBD. Vaping CBD is also a fantastic way to improve the compound's bioavailability. With a rate of roughly 50–80%, it's about as close to an intravenous dose as you can get. Inhaling vapor isn't suitable for everyone, as the degree of benefit will depend on your particular wellness needs. That said, for a potent dose of CBD, vaping remains one of the most effective administration methods.
In the pursuit of greater effectiveness, it isn't just a change in administration that can alter bioavailability. Instead, by making changes to the formula of a specific product, or by taking CBD alongside a meal, it's possible to improve the absorption rate.
A prime example of this improvement comes courtesy of liposomes, pharmaceutical-grade vesicles that enhance the amount of an active ingredient that reaches the bloodstream. These microscopic protective bubbles carry CBD to the target area while protecting it from digestive enzymes and making it easier for cells to absorb. We've simplified the concept somewhat, but liposomes remain a popular method of drug delivery, and a versatile option for improving the bioavailability of orally consumed CBD.
Another method of improving bioavailability is nanoemulsion. Again, we'll go easy on the technicalities, but essentially, nanoemulsion involves the use of ultrasonic waves to break CBD down into much smaller particles, thus improving absorption.
Usually, a straightforward workaround is blending CBD with a carrier oil (CBD is lipophilic, meaning it dissolves in fat). However, nanoemulsion aims to take things one step further and cut out the middleman. The result is a CBD molecule that can bypass the internal organs and travel straight to the bloodstream. The technique is still in its infancy, but we expect to see more nano-emulsified CBD products in the future.
If you lack the appropriate lab equipment, don't worry. A simple way to improve the bioavailability of CBD is to consume it with or shortly after a meal. Taking CBD alongside a high-fat meal or snack (avocado, nuts, or salmon, for example) plays to the compound's lipophilic nature. The extra fat helps make CBD more readily available, improving bioavailability without a liposome in sight.
Once you’ve identified the most effective method of consuming CBD—perhaps you’ve even decided to take it alongside a high-fat meal for an extra boost in bioavailability—surely that's all there is to consider?
Bioavailability will always be an important consideration for anyone looking to benefit from the holistic benefits of CBD. However, you should view it as one element of choosing the right product. Maintaining a consistent CBD level is just as crucial if you truly want to benefit from everything the compound has to offer.
Getting as much CBD as possible to the target area, as fast as possible, is great, but improved wellness is a marathon, not a sprint. As such, it's important to keep topping up your CBD levels with regular dosing to make sure it's ready to help when you need it most. And remember; the faster CBD reaches the bloodstream, the quicker it leaves the body too! It's all about balancing bioavailability and the benefits of different consumption methods with your individual needs.
Even if you were to administer CBD via a method that had 100% bioavailability, if the quality of the product were poor, the effects would be no more significant. It is also worth considering that oral consumption results in the compound staying in the body longer than other methods.
When deciding to take CBD, first think about what it is you are trying to achieve. If you're not using the compound to support a particular condition, then a general means of administration (oral/sublingual) should prove more than sufficient.
By taking all of these attributes into consideration, you can ensure your administration method is as effective as possible, regardless of how you choose to take CBD.
Ready to experience the bioavailability of different CBD products? Why not browse the Cibdol store to find a CBD oil, capsule, cream, or supplement that matches your needs? Or, if you still have questions about liposomes, nanoemulsion, and building a consistent CBD level, visit our CBD Encyclopedia.