How Does the Body Absorb CBD?
Scientists are regularly learning more about cannabidiol (CBD) and how it interacts with receptors throughout the body to elicit balancing and healing effects. Studies suggest that CBD may be able to minimize and even eliminate seizure activity , reduce anxiety and depression , manage pain , fight some cancers , and provide anti-inflammatory and neuroprotective effects that could potentially be beneficial for conditions like Alzheimer’s disease and arthritis . For CBD to have influence over our systems, the natural non-psychoactive compound first need to be absorbed.
When we talk about the absorption of CBD, we’re referring to its transfer from the site of administration to the bloodstream, where it can then be transported throughout the body to interact with or influence cannabinoid receptors CB1 and CB2 , and non-cannabinoid receptors like serotonin receptor 5-HT1A and vanilloid receptor TRPV-1.
How CBD is absorbed depends on the route of administration, or how it’s consumed. Whether CBD oil is ingested, situated under the tongue, inhaled, or applied topically plays an important role in the uptake, distribution, and elimination of the compound. It can therefore influence how effective cannabinoid treatments will be at eliciting their natural balancing effects.
Absorption After Ingestion and Sublingual Methods
The most common route of CBD oil administration is orally, or through the mouth. When CBD is ingested, it is absorbed by the digestive system. From the stomach, the compounds enter the hepatic portal system, where they are carried through the portal vein into the liver. The liver then metabolizes the CBD molecules, in what’s referred to as the “first pass effect.” CYP450 mixed function oxidases enzymes in the liver act upon CBD, reducing the concentration of the compounds before passing on what remains to the bloodstream.
Ingestion, while considered by most to be the easiest administration method, isn’t the most efficient for absorbing high levels of CBD. Studies have found, however, that consuming CBD oil with fatty acids can help bypass first pass metabolism and increase how much CBD is absorbed through ingestion.
If CBD oil is held under the tongue for 60 to 90 seconds before being swallowed, the mucus membranes in the mouth can absorb the compounds. This sublingual method allows CBD to completely bypass the digestive system and liver metabolism, so the compounds can avoid being broken down by enzymes and reach the bloodstream more quickly.
Absorption After Inhalation
When CBD oil in inhaled, such as through vaporization, the compounds are absorbed through the alveoli in the lungs, which offer a large absorptive surface area. Once through the alveoli, the CBD molecules are immediately transferred into the bloodstream. Compared to ingestion, the inhalation method allows more CBD to be absorbed and offers faster absorption.
Absorption After Topical Application
When CBD oil is applied topically , or directly to the skin, it never reaches the bloodstream but can be absorbed through the skin’s surface to interact with nearby cannabinoid receptors.
Human skin in general has low permeability, which means it blocks most substances from entering. The skin has a particularly low absorption rate for cannabinoids, so application of CBD balms, salves, and lotions need to be heavy enough to overcome this barrier. However, when applied liberally, CBD is permeable to the skin through its pores.
Now that you know that the way that CBD is absorbed varies depends on the administration method, you may decide that one method is more ideal than another depending on your needs. However, selecting the method with which you feel most comfortable is important as you’ll more likely be able to be consistent with your servings .
You can learn even more about CBD administration methods and the types of CBD products available on our education page .
Have specific questions about CBD absorption? Join our free ECHO Community to connect with physicians and others who have used or are using cannabinoids for health purposes.
Whether CBD is ingested, situated under the tongue, inhaled, or applied topically plays determines how the compound is absorbed.
Are cannabinoids absorbed through the skin?
Cannabinoids are garnering interest in the world of science. Dozens of these molecules appear in the cannabis plant, and many of them are showing promising results in animal and human studies.
Cannabinoids are typically ingested orally, sublingually, or inhaled through a vaporizer. However, cannabinoids such as CBD can also be found in a whole range of cosmetic products including creams, lotions, and balms. But how exactly do cannabinoids affect the skin? Do they pass through this protective barrier, or are their effects only skin-deep?
Do cannabinoids pass through the skin?
Upon applying a cannabinoid product to their skin, people often assume the cannabinoid enters their bloodstream. But just how true is this supposition? Well, it really depends. CBD and other cannabinoids can be applied to the skin in two distinct methods: topical and transdermal.
Topical application refers to creams, ointments, and other cosmetic products designed to be massaged into the epidermis—the topmost layers of the skin. These products target the skin itself and don’t ferry cannabinoids into the blood vessels of the derma below.
In contrast, transdermal products deliver CBD in a manner that penetrates through the upper barriers of the skin and into the bloodstream. Animal studies have shown that CBD administered as a transdermal gel makes its way into the bloodstream and increases plasma levels of the cannabinoid.
However, transdermal CBD isn’t just a matter of rubbing the cannabinoid into the skin. It requires several adjuvants to make a hydroalcoholic gel capable of penetrating the epidermis. THC also appears to permeate the skin through lipophilic pathways, as evidenced by a 1998 paper that showed transdermal application of delta-8-THC—a more stable form than delta-9-THC—to sustain delivery of the cannabinoid into the bloodstream over 24 hours.
Although studies on transdermal cannabinoids are few and far between, this method of application could serve as a way to bypass the digestive system and deliver cannabinoids directly into the bloodstream. This method of administration resembles the pathway of sublingual ingestion. Multiple patents exist for transdermal application of cannabinoids, and companies offer products featuring varying ratios of THC, CBD, CBN, and THCA.
How cannabinoids interact with the skin
Although transdermal delivery manages to introduce cannabinoids into the bloodstream, topical products offer a different advantage. The skin—much like many other areas of the body—harbours cannabinoid receptors. The endocannabinoid system (ECS) plays a regulatory role in the body and helps many different biological systems maintain homeostasis. The skin is no exception.
A review published in Trends in Pharmacological Sciences states that the endocannabinoid system of the skin plays a key role in several crucial processes. External cannabinoids share a similar structure to those found in the body, and also target the same receptor sites.
Cannabinoids and dermatological issues
Several studies have investigated the effects of cannabinoids on common dermatological issues. For example, a study in the Journal of Dermatological Science looked at the effects of this family of molecules against keratinocyte hyperproliferation, which is associated with
red, flaky, and scaly skin.
These uncomfortable symptoms arise as the immune system mistakenly attacks healthy skin cells—an issue of homeostatic regulation. This leads to a rapid build-up of skin cells on the surface of the skin. The study found THC, CBN, CBD, and CBG to inhibit keratinocyte production and help restore balance in the skin. That said, more studies are needed to confirm these findings.
Researchers also looked at how cannabinoids affect overproduction of sebum. When this oily substance builds up in the pores, bacteria can form and begin to cause red blemishes. Research published in The Journal of Clinical Investigation tested the effects of CBD on human sebocytes, cells that pump out excess sebum. The researchers found that cannabinoids might help these cells behave normally by acting on TRPV4 and A2A receptors.
Conclusion: cannabinoids and the skin
Although research remains in the early stages, cannabinoids certainly produce intriguing effects in regards to the skin. The discovery of the ECS in our largest organ raises many questions on the role(s) of cannabinoids in dermatological research.
Cannabinoids have a special relationship with the skin. Follow the link to learn how they interface with the endocannabinoid system in our largest organ.