What is Bioavailability and Why is it Important in CBD?
For any substance to have its desired effect once it has been absorbed by the body, it needs to reach systemic circulation in order for it to migrate to different areas to provide them with its benefits. Systemic circulation is what provides the functional blood supply to all body tissue, and bioavailability is extremely important in determining how much of a substance reaches this. This applies to products such as CBD oil too.
At a scientific level, bioavailability is essentially a sub-category of absorption. It refers to the percentage of a substance that reaches systemic circulation. This can be applied to the food that we eat and the medications and supplements that we consume. For example, while the body might absorb a certain percentage of the useful nutrients of a substance, an even smaller percentage of this actually reaches systemic circulation.
Ideally, the majority of those nutrients would reach the bloodstream for us to get the most out of them. However, our bodies aren’t 100% efficient, which means that not all of the nutrients are absorbed fully, with some being destroyed by the stomach and intestines, some being secreted back out, and there are also some that will not go inside the cells.
Generally, macronutrients including carbs and fats are highly bioavailable, meaning that when consumed, a large percentage of them are able to pass through to systemic circulation. Unfortunately, the more beneficial micronutrients that we value, such as vitamins and minerals, can be harder to absorb.
Still, it is important to remember that bioavailability is affected by a huge selection of factors, including the formulation of a substance, how it is administered, what you consume it with, other substances that it may encounter in your system, as well as your overall health. When it comes to useful nutrients, high bioavailability is favoured. This ultimately means that a higher percentage of them are used by the body after consumption, meaning that there’s no need to increase your quantities to experience the benefits.
The bioavailability of CBD
So what does this have to do with CBD?
As we’re well aware, it can offer many benefits when it comes to health and wellbeing, and its safe and non-addictive nature means that it can make a great alternative to many conventional medicines on the market. However, for it to have its desired effect, CBD not only needs to be absorbed into the bloodstream – it also needs to stay there long enough so it can reach your endocannabinoid system, where its benefits can take effect.
Not all CBD is the same, so there are many different factors that can affect its bioavailability. Firstly, it is fat-soluble as opposed to water-soluble, which means that it is similar to vitamins and minerals in the sense that it is difficult for the body to absorb. It can also be taken in a range of ways, including orally, inhalation and transdermal, which all have their own pros and cons and result in different absorption levels.
While inhaled CBD generally has a high absorption rate, meaning faster results, it isn’t the most beneficial choice for long-term use, as it can be damaging to the lungs over time. For this reason, while smoking and vaping CBD does have a high rate of bioavailability, it is possible that it could cause adverse health effects later on.
Transdermal CBD, such as adhesive patches, offers a slow and steady delivery, which offers some advantages for those who need to maintain consistent CBD levels in their bloodstream. However, as it is fat-soluble, the cannabinoids are repelled by the water-soluble layer of the skin, making it difficult to absorb.
For the most part, oral CBD has the lowest bioavailability of all delivery forms, as digestive acids and enzymes are likely to destroy a large portion of the substance before it has a chance to be absorbed. Plus, the small amount that does travel through the intestinal wall also has the barrier of being metabolised by the liver before reaching other areas of the body.
However, the pros outweigh the cons. Although absorption can be relatively low, this can be offset by the fact that its duration can be longer than other delivery methods. Scientific research has previously concluded that the average amount of time that an orally consumed CBD molecule stays in the body is 4.2 hours. In contrast, for injected CBD used in the same study, the average was 3.3 hours. Oral CBD has also been shown to lead to higher brain levels in comparison to inhalation methods.
Can bioavailability be increased?
While oral CBD absorption and bioavailability are low compared to other methods, there are ways of improving this. One way of achieving this is for it to be taken alongside supplements such as piperine, as there is evidence that this can increase and support the absorption of CBD.
Absorption of CBD is also significantly better when taken with food compared to on an empty stomach, and due to its fat-soluble nature, including a healthy source of fat with your meal such as nuts, seeds or high-omega-3 fish is likely to help it to dissolve into smaller particles that are easier to absorb.
Another way to improve the bioavailability of oral CBD is to opt for a product that has been specially formulated for faster absorption into systemic circulation. At Holistic Herb, our uniquely micro-emulsified CBD oils have vastly superior Total Bioavailability compared to many other products on the market. This means that they are more efficient, enter the bloodstream faster and remain there in higher quantities for longer so that you can experience the full benefits.
With over 98% of the active CBD in our products being fully absorbed, you can be confident that our level of bioavailability is helping to bring a more efficient product to the table.