CBD Bioavailability: What It Is & How to Improve It

I first became familiar with bioavailability — the potential for a substance to be absorbed by the body — when incorporating herbs and supplements into my wellness routine. When I started dabbling with CBD, I had a hunch it was something to pay attention to, so I did some digging.

I discovered that many factors influence the bioavailability of CBD, and many of these optimizations are controlled by the manufacturer. However, there’s a lot you as the consumer can do to control how well your body absorbs and utilizes CBD.

What CBD Bioavailability Means

What is CBD bioavailablity

CBD bioavailability is the degree to which CBD reaches the bloodstream after being introduced into the body (e.g., by ingesting or inhaling).

Depending on how CBD is consumed, it enters your body directly into the bloodstream or via the digestive system (and then into your bloodstream ). The bioavailability of CBD plays a role in how quickly and to what extent your body can process and utilize the cannabidiol.

Bioavailability, often expressed as a percentage, measures how much of a substance is absorbed and utilized by your body, as well as the rate at which this absorption occurs. High bioavailability means you get the maximum effect from the amount you take.

Why CBD Bioavailability Matters

So, what can you expect from a CBD oil product with greater bioavailability?

  • You'll likely notice the onset of effects sooner. For example, instead of waiting 90 minutes to feel something, it may take just 15 minutes.
  • Because it's kicking in more quickly, your CBD effect may peak faster or end sooner. Bioavailability impacts the half-life of CBD, which is the time it takes for half of the concentration of CBD in the body to be eliminated. Depending on the type of CBD you take, how often you take it, and other factors the half-life of CBD can range from less than two hours and up to five days.(1)
  • The effects of your CBD are likely to be more effective and efficient. This means that milligram for milligram or milliliter for milliliter, you're getting more benefits from your CBD.
  • You'll get more bang for your CBD buck. It may not take as much CBD to achieve desired outcomes — using less means buying less. This is great news whether you’re buying CBD for yourself or your pet.

While all cannabinoids interact with the body’s endocannabinoid system receptors, CBD has been shown to have particularly strong interactions with CB1 receptors. Increased bioavailability of CBD enhances its effectiveness, potentially providing greater relief from conditions like chronic pain and other desired outcomes.(2)

Ways to Take CBD

It makes sense that the bioavailability of a CBD product in part depends on its concentration. A product with 25 MG of CBD per dose provides more for your body to absorb than a product with 5 MG per dose.

What surprised me most is how widely bioavailability varies across the many forms of CBD. For example, if you took a 10 MG CBD gummy, your body will absorb less of it than if you took the same 10 MG dose by dropping CBD oil under your tongue.

Does this mean you should give up your favorite CBD gummies and only use CBD oil drops instead? Not at all! Every consumption method has its place, and there are things you can do to optimize forms with less-than-ideal bioavailability.

Let’s explore the different ways to consume CBD, how their bioavailabilities stack up to one another, and share some tips to enhance absorption.

CBD consumption methods

Oral CBD Bioavailability: Gummies, Softgels & Edibles

Edibles are a go-to for many CBD fans, and it’s easy to see why! Pre-measured, consistent, and often delicious doses are easy to take and fun to eat. 

That’s why I was initially disappointed to learn that , CBD oral bioavailability plummets due to the first-pass effect. The digestive system starts breaking it down, and the liver metabolizes much of it, leaving behind only a small portion. As a result, only between 6-20% of the CBD actually enters the bloodstream (3)

The good news is that you can improve the bioavailability with a few simple tricks. 

How to Hack Oral CBD Bioavailability

The first thing to understand if you want to get more mileage out of your edible CBD is that CBD is a lipophilic (fat-soluble) compound, meaning it dissolves better in fats than in water.

For example, a University of Minnesota study found that participants who took CBD with a high-fat meal saw up to a fourfold increase in blood CBD levels compared to those who took it on an empty stomach. (4)

"The type of food can make a large difference in the amount of CBD that gets absorbed into the body. Although fatty foods can increase the absorption of CBD, they can also increase the variability as not all meals contain the same amount of fat," said Angela Birnbaum, the study co-author and a professor at the College of Pharmacy.

Another way to capitalize on CBD’s lipophilic properties is to use CBD products formulated with carrier oils such as MCT oil or olive oil, which can help enhance the absorption of CBD.

Products like nano-emulsified CBD, where CBD particles are broken down into smaller sizes, can also increase the rate and extent of absorption, making the CBD more bioavailable. (5)

Sublingual CBD Bioavailability: CBD Drops & Sprays

You might file CBD sublingual bioavailability under CBD bioavailability hacks, too. One of the best ways to take CBD is by dropping or spritzing CBD oil or tincture under the tongue, it absorbs directly into the bloodstream via the sublingual gland, bypassing the digestive system and first-passing liver metabolism. This is known as sublingual consumption. 

Sublingual CBD offers a practical and discreet method with bioavailability between 19% and 35%. 

To ensure maximum absorption, hold the CBD under your tongue for 30-90 seconds before swallowing. This allows the mucous membranes sufficient time to absorb the cannabinoids effectively.

Vaporized CBD Bioavailability

CBD vaporizer pen next to hemp flower

Vaping CBD involves heating a CBD oil or e-liquid until it vaporizes, then inhaling the vapor into your lungs. The CBD is rapidly absorbed into the bloodstream through the lung's alveoli, bypassing the digestive system and liver, leading to an impressive vape CBD bioavailability of around 56%.(6)

One reason vaping boasts such high bioavailability is that the CBD avoids that pesky first-pass metabolism in the liver, which typically breaks down much of the CBD before it can enter the bloodstream.

However, while this method is efficient, it's not without risks. The long-term effects of vaping are still under research, and some users may experience irritation or discomfort in their respiratory system.

Smoked CBD Bioavailability

Smoking CBD, whether through a hemp cigarette or a CBD-rich strain of cannabis, is another method that offers relatively high bioavailability, typically ranging from 31% to 45%.(7) Like vaping, smoking delivers CBD directly to your lungs, where it quickly enters the bloodstream, bypassing the digestive system and liver.

Smoking has a slightly lower bioavailability than vaping because the liquids in CBD vape cartridges are intentionally formulated, whereas when you smoke flower, there can be variation in the natural product.

Rectal CBD Bioavailability

Yes, we’re going there! Rectal administration of CBD might not be the most popular method, but it offers unique benefits, including a bioavailability range of 13% to 40%.(8) CBD suppositories are inserted rectally, where they dissolve and the CBD is absorbed through the rectal mucosa, entering the bloodstream and bypassing the liver's first-pass metabolism.

This method can be particularly useful for individuals who cannot consume CBD orally due to medical conditions or who require localized relief in the pelvic region. The wide range of bioavailability can be attributed to factors like the type of suppository base used and individual differences in rectal absorption.

Intranasal CBD Bioavailability: Nasal Sprays

Are you as intrigued as I was to learn that CBD nasal sprays exist? This consumption method has a small but mighty fan base and with the bioavailability of intranasal CBD ranging from 34-46%, I predict a rising trend.(9)

The nasal passages offer a direct route to the bloodstream, so there’s no loss by passing through the liver and absorption is rapid.

The key to maximizing bioavailability with this method is ensuring that the nasal spray is administered correctly. Proper technique involves spraying the product into the nostrils and sniffing gently to draw the CBD into the nasal mucosa.

Topical CBD Bioavailability: Lotions & Creams

Applying topical CBD cream

Topical CBD products, like creams, lotions, and balms typically have a bioavailability of around 3%. When applied to the skin, CBD interacts with cannabinoid receptors in the epidermis and dermis but does not enter the bloodstream in significant amounts.

This isn’t to say there’s not a time and place for topical CBD. Nor should it be discounted altogether. While creams and lotions might not be the most bioavailable method for whole-body effects, they still offer benefits for localized issues such as pain or inflammation. By targeting specific areas, topical CBD keeps the cannabinoid concentrated where it’s needed most, making it my go-to for addressing localized discomfort.  

Additionally, CBD may promote overall skin health, by providing nourishment and supporting the skin’s natural balance. So, while it might not provide widespread effects throughout your body, topical CBD can still be a valuable addition to your wellness routine, particularly for targeted relief and skin care. 

Transdermal CBD Bioavailability: CBD Patches

Transdermal CBD, delivered through patches, provides a steady, controlled release of CBD through the skin into the bloodstream. Think of a nicotine patch, but the CBD version. 

СBD transdermal bioavailability is not yet known due to a lack of research, but the theory is that transdermal absorption allows for direct absorption into the bloodstream. However, keep in mind that your skin won’t absorb 100% of the product, which will impact the overall bioavailability.

CBD Bioavailability Chart

Oral CBDIngested, including drinks and edibles6-20%
Sublingual CBDDrops under the tongue19-35%
Vaped CBDInhaled from a vaporizer56%
Smoked CBDInhaled from a joint, pipe, or dab rig31-45%
Rectal CBDRectal suppository13-40%
Intranasal CBDSprayed in the nose34-46%
Topical CBDCreams and lotions applied to the skin3%
Transdermal CBDPatch applied to the skin Unknown

Maximizing The Bioavailability Of CBD

CBD is available in various formulations — gummies, tinctures, soft gels, etc. — and can be taken in several ways — ingested, intranasally, topically, etc.

The bioavailability of CBD is influenced by its form, concentration, and consumption method. Each method translates into different levels of bioavailability.

How to Increase CBD Absorption? 

There are other tips and tricks to increase CBD bioavailability. You can try:(10)

  • Consuming CBD on a full stomach
  • Taking your CBD with a snack or meal that has some fat in it
  • Taking CBD that is made with carrier oils
  • Finding CBD products that leverage technology (e.g., nanotechnology or liposomal encapsulation)(11)

<H2>Absorb This: High CBD Bioavailability’s a Good Thing

With so many forms of CBD available, it's helpful to know which are easiest for your body to absorb so that you can avoid costly trial and error. However, bioavailability doesn’t have to be the only factor when choosing products. You should also consider your personal needs and preferences. I, for one, will still be enjoying my beloved CBD gummies and topicals!

CBD Bioavailability FAQs

What is bioavailability?

Bioavailability is the proportion of a substance — like CBD — that your body can absorb and utilize.

How do you increase CBD absorption?

Consider forms of CBD with higher bioavailability such as sublingual, vaping, and intranasal. Consume your CBD with food, especially those that contain healthy fats, and use nano CBD products. 

What is the bioavailability of CBD?

It depends on the formulation and method of administration. On the high end of the spectrum are inhaled and sublingual CBD; topical and ingested CBD are on the lower end.

What is the best way to take CBD?

As we’ve learned, the first-pass effect is going to do a number on your CBD bioavailability. That means methods that bypass the liver and digestive system such as vaping, sublingual drops, and nasal sprays will result in more CBD in your bloodstream.

You should always assess your personal needs and weigh the pros and cons of each consumption method. For example,  there are health risks associated with smoking and vaping. If you’re concerned about lung health, sublingual or intranasal varieties of CBD — like CBD tinctures — are probably going to be your go-tos. 

What is the half-life of CBD?

The half-life of CBD can range from less than two hours and up to five days depending on the form of CBD and other factors such as how consistently it’s used. 


  1. How Long Does CBD Stay in Your System? Healthline.
  2. Cannabinoids and Pain: New Insights From Old Molecules. Pharmacology.
  3. Critical Aspects Affecting Cannabidiol Oral Bioavailability and Metabolic Elimination, and Related Clinical Implications. CNS Drugs.
  4. High fat foods can increase oral cannabidiol absorption into the body. Science Daily.
  5. Recent Advances in Nanoparticle-Mediated Delivery of Anti-Inflammatory Phytocompounds. International Journal of Molecular Science.
  6. Human Cannabinoid Pharmacokinetics. Chemistry & Biodiversity.
  7. A Systematic Review on the Pharmacokinetics of Cannabidiol in Humans. Frontiers in Pharmacology.
  8. The effect of orally and rectally administered Δ 9-tetrahydrocannabinol on spasticity: A pilot study with 2 patients. International Journal of Clinical Pharmacology and Therapeutics
  9. Cannabidiol bioavailability after nasal and transdermal application: effect of permeation enhancers. Drug Development and Industrial Pharmacy.
  10. High fat foods can increase CBD absorption into the body. UMN News & Events.
  11. Recent Advances in Nanoparticle-Mediated Delivery of Anti-Inflammatory Phytocompounds. MDPI.
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About the Author

Green Bee Life founder Maria Calabrese author photo

Maria Calabrese, JD, MS

As the founder of Green Bee Life, Maria Calabrese is dedicated to raising consumer awareness within the cannabis industry, filling informational gaps, and fostering consumer confidence. Her work focuses on empowering consumers with the knowledge needed to make informed decisions, ensuring they find the most suitable cannabis solutions for their wellness needs. Maria's expertise helps bridge the connection between consumers and innovative cannabis insights, advocating for informed choices in the evolving landscape of cannabis as a wellness solution.

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