Bioavailability is a term used to describe the proportion of a substance that gets absorbed into your bloodstream and is made available for your body to use.
It is measured by the percentage that’s absorbed in the body compared to the product dose. For example, if 100 mg of a drug is taken orally and 40 mg of this drug is absorbed unchanged, the bioavailability is 0.4 or 40 percent.
In the case of cannabis, the active compounds are cannabinoids like CBD and THC. Depending on how you choose to consume cannabis, you could be absorbing less than 10% of the total cannabinoids that are present in a given dose.
Many things can affect how well your body absorbs cannabis, including your age, general health, certain gastrointestinal disorders, and whether or not the product is taken with food. However the most important factor in determining the bioavailability is the way cannabinoids are delivered into the body. (ie. whether you swallow or inhale it).
Studies have shown the bioavailability of THC through the oral route (ie an oil or edible) is approximately 10-20%, which means that 10-20% of the medicinal cannabis' active ingredient eventually reaches the bloodstream.
In the case of the Storz & Bickel range of approved medical device vaporisers, studies have been conducted to establish the bioavailability of cannabinoids when consumed through them.
These studies showed that the bioavailability of cannabinoids when consumed through the Volcano Medic 2 valve balloon is almost 50%. When consumed via the Volcano Medic 2 Tube Kit, bioavailability is approximately 43%. And the Mighty Medic bioavailability is approximately 32%.
To give you an idea of what these numbers mean in real terms, the table below shows how much of a 100mg dose of a 19% THC strain of dried cannabis flower is consumed into the bloodstream.
|VAPORISER||CANNABINOID CONTENT OF DRUG||CANNABINOID CONTENT IN BALLOON / TUBE / AEROSOL||CANNABINOID CONTENT IN BLOODSTREAM AFTER INHALATION|
|Volcano Medic 2 - Valve Balloon||THC: approx 19mg||approx 15mg||approx 10mg|
|Volcano Medic 2 - Tube Kit||THC: approx 19mg||approx 12mg||approx 8.25mg|
|Mighty Medic||THC: approx 19mg||approx 9.5mg||approx 6mg|
And importantly, the higher the bioavailability, the lower quantity you need to dose to experience the effects. And with the relatively high price of medicinal cannabis products in New Zealand, bioavailability efficiency is key to getting the most out of your medicines.