A recent article in Forbes has been making the rounds in the news and CBD community that suggests users of CBD may be at an elevated risk of liver damage. This sensationalist claim has since been rebutted by respected CBD industry organizations including ProjectCBD.org and Leafly.com.
In this article, we discuss what this all means and whether users should really be alarmed by the original claim.
January 2022 Update: A new study released on 1/3/2022 concluded that “self-medication of CBD does not appear to be associated with an increased prevalence of liver toxicity.” View the full story on the U.S. Hemp Roundtable website which includes a link to the full study and results.
The Studies in Question
“Hepatoxicity”, or drug-induced liver damage, is the topic of discussion in the news articles. The claim of the original article was drawn from a preclinical study that used mice in two separate experiments.
To summarize the experiments, the first one looked at the impact that a single, large dose of CBD could have. The other looked at the impact that slightly lower doses could have when taken over a longer period of time.
The doses given in the first experiment were along the lines of 0, 246, 738, or 2460 mg/kg of CBD. The doses in the second were given at 0, 61.5, 184.5, or 615 mg/kg of CBD over a period of multiple days.
These doses were chosen because they were determined by the researchers to be the “allometrically scaled mouse-equivalent doses (MED) of the maximum recommended human maintenance dose of CBD in Epidiolex.”
For reference, the safe maximum daily dose for humans determined by GW Pharmaceuticals (the company that developed Epidiolex) is 20 mg/kg.
The result? Mice on the highest doses of 738 and 2460 mg/kg in the first experiment did exhibit liver toxicity. In the second experiment, some of the mice on the highest 615 mg/kg dose were exhibiting liver toxicity and were killed by the researchers.
The rest of the mice at lower doses did not exhibit liver toxicity and finished the rest of the experiment with no problems.
What Does This Mean?
It may be true that CBD can cause liver toxicity in mice when they are given extremely high doses. But animal studies don’t always translate directly to how things will present in humans.
The issue of most concern is that the mice were give extremely high doses of CBD, especially when their relative weight is taken into account. The amount of CBD given to the mice that had issues were at around 10X the recognized safe limit for humans.
When you convert the amount the mice were taking at the highest dose to the amount a 100 pound human would take, it would be around 111,583 milligrams of CBD. For reference, CBD users in our Facebook group typically take anywhere from 5 milligrams to 100 milligrams per day. It’s not typical to see users exceed those daily levels.
Additionally, some believe that the presence of Hexane in the CBD used, a known hepatotoxin, could have influenced the results of the experiments.
In Summary – Does CBD Cause Liver Damage?
One minor study, using extremely and unreasonably high doses of CBD on mice, is not definitive proof that CBD causes toxicity to the liver. As long as users take CBD separate from other medications, especially those that already cause liver issues (like Tylenol), and keep to the recommended safe dosages for CBD, there is currently nothing to suggest that users have a higher risk of liver damage.
We always recommended that you speak with your doctor before starting CBD oil. This is especially true if you are taking prescription medications or if you have specific health concerns.