What the heck is bioavailability?

Bioavailability is a term that gets thrown around a lot in CBD and pharmaceutical circles. If you’ve been paying attention to the CBD world, chances are you’ve heard it by now. You might have heard it in the context of comparing different forms of CBD products, like edibles vs. vaping. You might have heard it mentioned alongside the term “absorption.”

But… what the heck is it?

In a nutshell, bioavailability refers to the amount of a given drug or compound that actually gets absorbed by your body when you take it. A compound like, for example, CBD.

According to Applied Biopharmaceutics and Pharmacokinetics by Leon Shargel and Andrew B. C. Yu, bioavailability is defined as “a measurement of the rate and extent to which a drug reaches at the site of action.”

Basically, it’s the answer to the question, “how much of this stuff is actually being absorbed?”

How does it apply to CBD?

So now we know that bioavailability means “how much of this is my body really absorbing?”

Next question: what is the bioavailability of CBD products?

It all comes down to one thing: how you ingest them.

Different ingestion methods have different bioavailabilities. That’s because of the way they get processed and broken down by your body, based on the way you consumed it. For example, vaping CBD has a different bioavailability than eating an edible. Taking a tincture under your tongue has a whole different bioavailability. So the amount of CBD actually entering your bloodstream can vary quite a bit depending on how you’re taking it.

How much can it vary, exactly?

I’m glad you asked.

On the low end of absorption, you’re looking at about 6%. On the high end, 50%. Which delivery method is the most efficient? Let’s take a look:

Bioavailability by ingestion method

So by now we know what bioavailability is, and we know it varies depending on the way you consume your CBD.

But how efficient is each of the most popular ways to take CBD?

From lowest to highest:

Oral (edibles, drinks, capsules and tablets): 6-15% absorbed

Sublingual (oils and tinctures): 15-30% absorbed

Transdermal (topicals, creams and lotions): up to 45% absorbed

Inhaled (vapes): 30-50%

So let’s say you consumed 20mg of CBD. How much of that would actually make it into your bloodstream?

If you ate a gummy, you’d absorb between 1.2 and 3mg.

If you took a tincture or oil, you’d absorb between 3 and 6mg.

If you applied a lotion, you’d absorb up to 9mg.

And if you vaped it, you’d absorb up to 10mg.

You can see how the form of CBD that you choose can have a pretty big effect on what actually goes in your body. So the next time you’re deciding which CBD product to buy, there’s one more thing to consider – how much CBD will you really be getting out of it?