As the main non-psychoactive cannabinoid found in cannabis, CBD (cannabidiol) interests many patients more than the psychoactive THC (tetrahydrocannabinol). However, thanks to THC's long and complicated legal history, it is this cannabinoid that has received the majority of scientific attention. Today, as we know that cannabinoids have many medicinal properties, non-psychoactive cannabinoids like CBD are gaining attention from researchers.
But how long does CBD stay in the body? What does it convert into when it is metabolized? Can using CBD products result in a positive drug test? With the growth of the CBD product industry, many people are wondering how cannabidiol affects our bodies and how long it can stay in the body.
How the human body processes cannabinoids
The most popular cannabinoid-based products fall into two categories - food products and inhalation products, such as dried CBD. The body processes food products (capsules, food, and to some extent tinctures and oils) through the digestive tract. After absorption through the gastrointestinal system, the liver metabolizes these compounds into other compounds. Inhaled cannabinoids (vaporized or smoked) travel through the respiratory tract for absorption across the cell membrane of the lungs.
Most studies on edible forms of cannabis have shown maximum plasma THC concentrations within one to two hours after ingestion. In comparison, the maximum plasma concentration of THC after smoking is reached within ten minutes. These studies focused on THC, but a similar time frame can be assumed for other cannabinoids such as CBD.
Regardless of the method of ingestion, the liver eventually processes all cannabinoids and converts them into compounds called cannabinoid metabolites. Scientists have studied the properties of some metabolites, and for example, THC turns into "hydroxy THC" or THC-COOH, which is essentially a more intoxicating cannabinoid than THC.
How does the human body metabolize CBD?
What about the metabolites of CBD? In an article published in Cannabis and Cannabinoid Research, authors István Ujváry and Lumír Hanuš explain: "There are no publications describing the biological activity of CBD metabolites in humans. However, at least twenty CBD metabolites have been identified in their study, although most of them have only been identified in animal studies or in the laboratory. The most common are hydroxylated 7-COOH derivatives of CBD. These include compounds such as 2-OH-7-COOH, 10-OH-7-COOH and other similarly structured CBD metabolites.
How long does CBD stay in the body? Many factors affect how long CBD metabolites will remain in the human body. For example, CBD and its metabolites are fat-loving molecules. Naturally, the human body stores them in fat cells. A high body mass index (BMI) would mean that CBD metabolites will persist longer in the body, while a lower BMI would suggest faster excretion of cannabinoids from the body.
How quickly does CBD take effect?
How long does it take from the time you vaporize, burn or ingest CBD before you feel the effects? Unlike THC, which has intoxicating effects, CBD's effects are much more subtle. Patients generally do not feel the effects as they would with THC-rich products. CBD consumers often say that the onset of effects is rather mild, compared to THC products. Cannabidiol doesn't cause a sudden hit, and the effect is felt rather after a while, when you realize that you feel different.
Importantly, patients need to know that the method of consumption affects the duration of effect. Smoking dried CBD or vaporizing CBD flowers is the fastest way to deliver cannabidiol, and the effects should be felt within one to ten minutes. Of course, vaporization is a healthier and more efficient method than smoking, which we do not urge you to do. Cannabinoids inhaled with smoke or vapor from a vaporizer, while fast acting, are also the fastest to stop working. CBD flowers produce quick effects when burned or vaporized, but they last shorter than if you consume CBD oils.
Oral CBD sprays, sublingual CBD oils, and tinctures are the products that produce the fastest effects immediately after smoking and vaporizing. CBD can be absorbed through the permeable mucous membrane of the mouth (under the tongue), allowing CBD to enter the bloodstream relatively quickly. Patients can expect relief within thirty minutes, and the effects should last up to six hours (depending on CBD concentration and dose size).
CBD foods produce the longest effects, but we also have to wait the longest for them. Depending on the patient (and when they last ate), it can take one to two hours for the edible forms of CBD (or capsules) to start working. The effects of potent CBD edibles can last more than six hours.
How long does CBD stay in the body?
According to a "Systematic review of cannabidiol pharmacokinetics in humans" published in Frontiers in Pharmacology (2018), the length of time CBD stays in the body varies depending on the method of ingestion. Sophie A. Millar, Nicole L. Stone, and others published a report that analyzed over 700 studies and considered twenty-four that included the pharmacokinetic properties of CBD in humans.
Millar and her team found that the half-life of smoked and vaporized CBD was 31 hours after inhalation. The half-life after using an oral CBD spray was between 1.4 and 10.9 hours after ingestion, and regular consumption of CBD oils and food products had the longest half-life of more than five days.
What about CBD and drug testing?
Fortunately, today patients don't have to worry that their daily dose of CBD will trigger a false positive drug test. Drug tests conducted for employment reasons or for legal reasons only target THC and THC metabolites. At the time of writing this article, I have not found drug tests that also test for CBD (or CBD metabolites). However, CBD-rich hemp seed contains a small concentration of THC (less than 0.2%), so some tests may test positive for THC in the body - see our article for more information: CBD vs drug tests.
While some experts claim that extremely high doses of CBD can somehow trigger a positive test, there is no such relationship well and thoroughly described in the literature. People who regularly use CBD should not be concerned about taking a drug test, but there are many factors that can affect the persistence of even small amounts of THC in the body.
More research is needed on the effects of CBD on the human body
Right now, research on CBD and the human body is at a very early stage. Scientists know that the method of consumption affects the duration of CBD and the half-life of CBD metabolites in the body, but these results are only preliminary. For those wondering "how long does CBD stay in the body?", it is safe to assume that it stays in the body for a similar amount of time as its cousin THC.
As with THC, the method of consumption, the patient's metabolism, BMI, and other physiological factors likely affect how long CBD is removed from the body. However, these are only speculations. The science around CBD is largely still in the preclinical phase, so more time must pass before we have a full picture of how CBD affects the human body.