For CBD, bioavailability is an important concept. This is because, depending on the condition being treated, the compound could be more effective if administered in a certain way. Before we detail the estimated bioavailability of specific administration methods, let’s take a closer look at what exactly the term means.
Bioavailability is the degree to which any substance reaches the intended site of action. Medication administered intravenously has 100% bioavailability, and this will act as our benchmark. If a compound is administered via other means (oral, sublingual, topical), then it has to travel through various parts of the body before it reaches the bloodstream—the greater, or more complicated, this journey, the lower the bioavailability of a compound.
In the case of CBD, our aim is for the compound to enter the bloodstream where it can be circulated throughout the body, thus providing the most significant benefit. The reality is that although a drop of CBD oil may contain 2mg of CBD, for example, a lesser amount of that dose will reach the bloodstream. Therefore, the intensity and effectiveness of CBD oil hinge greatly on bioavailability. Obviously, intravenously administering CBD is not possible, advisable, nor realistic. Instead, we can look at what the estimated bioavailability is of popular administration methods.
Oral consumption of CBD is the most popular option. However, once consumed, the compound has to contend with several biological processes before it can reach 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%. On average, somewhere in the middle of this range is a reasonable assumption for the bioavailability of orally consumed CBD.
Although very similar to oral consumption of CBD, sublingual administration relies on the capillaries beneath the tongue for the compound to enter the bloodstream. This is achieved by placing a few drops underneath the tongue and holding them there to be absorbed by the mucous membrane. By utilising CBD tinctures or sprays, it is possible to achieve a higher bioavailability than oral administration, although the exact improvement rate has yet to be quantified.
According to anecdotal accounts, sublingually dosing CBD is a simple and effective way of increasing the onset of its effects. Because it doesn't have to contend with passing through the liver and the GI tract, CBD is expected to reach the bloodstream at a faster rate.
CBD-infused creams have the lowest bioavailability of all three administration methods. Cannabidiol is naturally hydrophobic, so the skin does a good job of keeping it out. That is also the reason CBD is mixed with a carrier oil and nothing else—hydrophobic means it is adverse to water and will repel it.
Topicals are expected to have a bioavailability of between 5–10%. Although this may sound like a poor return, the beauty of topicals is that they are administered directly to the skin for local relief. The formula of the cream will help the compound to be absorbed into the skin where it can start providing therapeutic relief on a cellular level. So it may not travel around the body much with this method, but it is highly effective for the areas it is applied to.
Aside from changing the way you take CBD, bioavailability can be improved by utilising liposomes. We have already extensively covered the benefits of liposomes, but their principle is simple.
Liposomes are tiny vesicles that form a protective barrier around CBD molecules. Once inside this bubble, CBD is transported safely through the digestive tract and shielded against various digestive enzymes. Moreover, thanks to liposomes’ unique hydrophilic head and hydrophobic tail, they are more readily absorbed by the intestinal membrane than a CBD molecule alone would be.
Liposomes can be used in both oils and creams to improve the bioavailability of CBD. Thanks to sophisticated scientific techniques, liposomes have 100% trapping effectiveness—none of the CBD is wasted.
Bioavailability will always be an important consideration for anyone looking to benefit from the therapeutic effects of CBD. However, it should be viewed as one element of choosing the right product.
Even if you were to administer CBD via a method that had 100% bioavailability, if the quality of the product were poor, subsequent effects would be no more significant. It is also worth considering that oral consumption results in the compound staying in your body for a longer period than other methods. When deciding to take CBD, first think about what it is you are trying to achieve. If the compound is not being used to support a particular condition, then the general means of administration (oral/sublingual) should prove more than sufficient.
We cannot say that this is the case for every producer of CBD. However, at Cibdol, we take pride in our golden-grade CBD with its market-leading purity and verified test results. It also contains a diverse range of cannabinoids and terpenes to make full use of the entourage effect. By taking all of these attributes into consideration, you can make sure your administration method is as effective as possible, regardless of how you choose to take CBD.