Figuring out the metabolic pathways of CBD will help physicians determine frequency of dosing.
As the primary non-intoxicating cannabinoid in cannabis, many patients are just as curious about CBD as they are about THC. Yet, with a long and complicated legal history, THC gets most of the scientific attention. Today, with cannabinoids more widely accepted as a medicine, the attention is shifting towards the other less controversial cannabinoids. How long does CBD stay in your system? And what does it transform into when metabolized? Does it appear on drug tests? Suddenly, with the rise of CBD for medicinal applications, there is much more curiosity about the inner workings of CBD as it travels through the human body.
How the Human Body Processes Cannabinoids
The most popular cannabinoid products fall into two categories — edibles and inhalables. The body processes edibles (capsules, infused foods, and to some degree, tinctures and oils) through the digestive tract. Once absorbed through the gastrointestinal system, the liver metabolizes these compounds into other compounds. Inhaled cannabinoids (vaporizer or smoked) travel through the respiratory tract for absorption through the cellular lining of the lungs.
Most studies on edible forms have found maximum THC plasma concentrations (blood levels) within one to two hours following ingestion.[1]Sharma, P., Murthy, P., & Bharath, M. M. (2012). Chemistry, metabolism, and toxicology of cannabis: clinical implications. Iranian journal of psychiatry, 7(4), 149–156. On the other end of the spectrum, maximum THC plasma concentrations from smoking tend to peak within ten minutes. Historically the focus of the research was on THC, but one can assume similar timeframes for other cannabinoids.
No matter the method of consumption, the liver eventually processes all cannabinoids and turns them into compounds called metabolites. Researchers have discovered therapeutic value for some cannabinoid metabolites, and many have unique qualities. For example, THC turns into “hydroxy THC” or THC-COOH, which is an exponentially more intoxicating compound.
How the Human Body Metabolizes CBD
What about CBD metabolites? In a paper 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, their research identified at least twenty CBD metabolites, although most of these have only been identified within animal studies or in a laboratory. The most common are hydroxylated 7-COOH derivatives of CBD. These include compounds like 2-OH-7-COOH, 10-OH-7-COOH and other similarly structured metabolites.[2]Ujváry, I., & Hanuš, L. (2016). Human Metabolites of Cannabidiol: A Review on Their Formation, Biological Activity, and Relevance in Therapy. Cannabis and cannabinoid research, 1(1), 90–101. … Continue reading
How long does CBD stay in your system? A wide variety of factors impact how long these metabolites linger in the human body. For example, CBD and its many metabolites are fat-loving molecules with high lipid solubility. Naturally, the human bodies store them within fat cells. A high Body Mass Index (BMI) would mean longer-lasting CBD metabolites, while a lower BMI would suggest faster excretion of the cannabinoid compounds.
How Long Does CBD Take to Kick in?
From the time of inhalation or ingestion, how long can a patient expect to wait before they experience the benefits? Unlike THC, which comes with intoxicating effects, the effects of CBD are markedly more muted. Patients generally don’t feel the effects coming on like they would with a THC-rich product. Often, CBD is a quiet onset and a reduction of symptoms rather than an apparent hard-hitting experience.
Importantly, patients need to know that the method of consumption impacts the time of onset. Inhalation of smoked or vaporized CBD-rich flower is the speediest route of delivery, and the effects should become apparent within fifteen to twenty minutes. Inhaled cannabinoids, while quick to take effect, are also the fastest to fade away. Relief from smoked or vaped CBD will dissipate within a few hours.
Relief from CBD oral sprays, sublingual drops, and tinctures have the second-fastest onset. Allowed to absorb through the permeable lining of a patient’s mouth, CBD quickly enters the bloodstream. Patients can expect relief within thirty minutes, which should last for upwards of six hours (depending on strength and dose size).
Finally, edibles are the longest lasting option for relief, but they often take the longest to develop. Depending on the patient (and what they had for lunch), the onset of a typical CBD-edible (or capsule) may take roughly one to two hours. A strong CBD edible can last for over six hours.
How Long Does CBD Stay in Your System?
According to the “A Systematic Review on the Pharmacokinetics of Cannabidiol in Humans” published in Frontiers in Pharmacology (2018), the lifespan of CBD varies depending on the method of consumption. The review, authored by Sophie A. Millar, Nicole L. Stone, et al. analyzed over 700 hundred studies and included twenty-four, which covered the pharmacokinetic properties of CBD in humans.[3]Millar, S. A., Stone, N. L., Yates, A. S., & Osullivan, S. E. (2018). A Systematic Review on the Pharmacokinetics of Cannabidiol in Humans. Frontiers in Pharmacology, 9. doi: … Continue reading
Millar and her team determined the half-life of smoked CBD is thirty one hours after inhalation. CBD oral sprays had a half-life of between 1.4 and 10.9 hours after consumption, and finally, chronic oral administration had the most prolonged half-life of upwards of five days.
What About CBD and Drug Tests?
Thankfully, patients today don’t need to worry about their daily CBD dose triggering false-positives on a drug test. Drug tests required for employment or legal reasons are exclusively geared towards THC and THC metabolites. At the time of writing, there were no known drug tests also looking for CBD (or CBD metabolites).
While some experts theorize that extremely high doses of CBD may somehow trigger a positive test result, these are theories only. There are no detailed, well-controlled accounts of this happening in the peer-reviewed literature. For the everyday patient regularly taking CBD, there should be no concern about tripping up a court-mandated or employer-required drug test.
More Research Needed on CBD and the Human Body
As it stands, research into CBD and the human body is in the very early stages of development. Researchers know the method of consumption influences CBD’s lifespan, but these results are preliminary. For those patients wondering “how long does CBD stay in your system?,” it’s safe to assume it follows a similar timeline to its cousin cannabinoid — THC.
Just like THC, whether it is inhaled or ingested, the patient’s metabolism, BMI, and other physiological factors likely influence the lifespan of CBD. Still, these are only educated guesses. The science around CBD is largely still in the preclinical stages. More time must pass before the full picture becomes clear of what happens to this therapeutic compound in the human body.
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