Why Do We Take CBD Under the Tongue?

Why Do We Take CBD Under the Tongue?

Why do we take CBD oil sublingually (under the tongue)?

Whether you’re new to CBD or if you’ve been taking CBD for some time, you might be wondering why there are so many CBD oils out there, and why people are obsessed with taking this sometimes-odd-tasting oil under their tongue.  Why not take a pill, like we’re so accustomed to doing?  Well, to answer that question, it helps to understand how CBD is processed in your body.

When you take CBD oil sublingually, you’re essentially finding the path of least resistance.  You’re adding CBD into your body using a fast and effective method.

Since your body is not breaking down the CBD, it’s entering the blood stream faster, making it more “bioavailable” and thus more effective.    Let’s explore these two ideas a little more.

How does taking CBD under the tongue absorb so quickly into the body?

Your mouth contains mucus membranes and capillaries.  When you hold the CBD under your tongue and wait the 60-90 seconds for the CBD oil to be absorbed, most of the oil is absorbed through the mucus membranes and enters the bloodstream much more quickly than it would if you had taken the CBD oil orally – swallowing all of it, like we normally do when we’re taking a prescription pill.   

CBD Under the Tongue

When you swallow CBD oil, it’s broken down through the digestion tract.  The digestive juices in your stomach will break down some of the CBD and then pass a portion of the CDB to the liver from the intestines, where your liver enzymes will further break down the CBD. We know this process as the first pass effect. 3   

It is here where the remaining CBD enters the bloodstream.  This digestive process could take almost two hours and reduces the actual amount of CBD you initially consumed. 

How is taking CBD under the tongue more effective?

CBD taken under the tongue is absorbed directly into the bloodstream, avoiding the first pass metabolism from the liver.  As a result, you have more CBD going directly to the bloodstream or a higher bioavailability, than taking the same CBD orally.  CBD oil taken sublingually has bioavailability of between 13-20%.

There are some studies suggesting the percentage may be as high as 35%.1 That means that if you take 100 MG of CBD sublingually, 20 MG is actually entering into your bloodstream. 

Anything taken orally (swallowing) is broken down by the gastrointestinal tract, while it goes through the stomach and then by the liver.  This reduces the original amount of CBD oil you’ve taken and thus reduces its effectiveness.  As a result, CBD oil taken orally has a bioavailability between 13 -19%. 

There are some studies suggesting bioavailability can be as low as 6% due to the digestion.2   

To use the 100 MG of CBD again as an example, you could potentially be taking as little as 6 MG of CBD.   Furthermore, it can take your body up to two hours to process this CBD - much longer than if you had just taken the CBD sublingually, thus reducing the effectiveness of the sublingual method.  This is critical for individuals who are seeking immediate relief for something like anxiety or pain.  

What are other ways to take CBD?

There are many ways to consume or add CBD into your daily routine.  We already discussed two of the most popular ways, sublingually and orally. 

There are many others, each with their own techniques and bioavailability. In addition to taking CBD sublingually, the other, more popular methods for taking would be to inhale CBD or to use a CBD topically.  


Inhaling CBD has become both a popular trend and a source of relief for individuals who need immediate results. Inhalation can affect the body in under 10 minutes; however, the effect lasts about 1-3 hours. 

Inhaled CBD can come in many forms, including herb vaporizers, an e-liquid cartridge, vape juice or more hemp flower-based products like CBD cigarettes, CBD flower or CBD pre-rolls.  When you inhale CBD, the CBD enters the bloodstream through the lungs, completely bypassing the digestive system.

The bioavailability of inhaling is higher than that experienced after taking CBD sublingually, and can go as high as 35%.3 Inhalation, however, is not for everyone.  Many complain of coughing, lung irritation, the smell of the smoke and simply being reluctant to smoke.  

Topical Products

CBD topicals offer another delivery method and are ideal for those who want to treat localized areas like a knee or a hand. 

Topicals aren’t suited for individuals who have pain in larger areas (like an entire leg, for example) or throughout the body.  Since topical creams and salves don’t penetrate the skin barrier, they’re not bioavailable. 

As such, CBD topicals don’t enter the bloodstream.  They prove to be a popular alternative for those who are concerned about taking CBD orally and passing a drug test.

  1. https://www.cbdoil.org/cbd-bioavailability/
  2. https://www.cbdoil.org/cbd-bioavailability/
  3. Leonard Leinow & Juliana Birnbaum, CBD A Patient’s Guide to Medicinal Cannabis (North Atlantic Books, 2017), p. 44.
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