Can CBD Cause Liver Damage? | Human Research Review
What Human Research Tells Us About CBD and Drug-Induced Liver Injury
Short Answer
Clinical doses of CBD can cause elevated liver enzymes, but that isn't necessarily evidence of permanent liver damage.
The evidence for permanent liver damage is thin. The evidence for clinically significant liver injury at typical wellness doses of 50–300 mg/day is limited.
First, elevated liver enzymes don't necessarily indicate clinically significant liver injury. Some drugs can elevate liver enzymes without producing long-term liver damage.
Second, much of the research on CBD doses large enough to elevate liver enzymes has involved people with Dravet syndrome or Lennox-Gastaut syndrome. These populations have higher rates of abnormal liver markers, potentially due to their antiseizure medications and other factors.
Consequently, the risk of CBD-induced liver injury observed in these populations may overestimate the risk for otherwise healthy adults using lower doses.
Nonetheless, some people will experience adverse effects from CBD, and there's no established dose at which CBD is completely risk-free.
Key Takeaways
What We Know
CBD can cause clinically significant liver enzyme elevations. Risk appears to increase with dose and certain medication combinations.
What the Evidence Suggests
Most documented cases resolve after CBD is discontinued or treatment is adjusted. Serious, lasting liver injury is much less well documented than transient enzyme elevations.
What We Don't Know
The precise risk at typical consumer doses, which individuals are unusually susceptible, and the long-term consequences of continued CBD use in people who develop elevated liver enzymes.
What This Doesn't Establish
The evidence discussed here does not establish that any product sold by Herbal Edge diagnoses, treats, cures, or prevents disease or injury.
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What Have Researchers Found?
Multiple clinical trials have demonstrated that CBD can significantly elevate liver enzymes ALT and AST. These elevations are often used to identify potential drug-induced liver injury (DILI) and remove people from studies before lasting damage might develop.
However, ALT and AST don't directly tell us whether the liver has lost its ability to function or whether lasting damage has occurred.
A 2023 systematic review covering 28 clinical trials and 1,533 CBD-treated participants found:
- 7.4% pooled incidence of elevated liver enzymes.
- 2.96% pooled incidence of elevations meeting the researchers' criteria for DILI.
- Higher risks associated with large CBD doses and concurrent antiseizure medications, particularly valproate.
- Most reported elevations resolved after CBD was discontinued.
- No cases meeting Hy's Law criteria, a warning sign for potentially severe DILI.
These findings also included healthy adults taking CBD alone, demonstrating that significant enzyme elevations can occur without drug interactions.
How Much CBD Does It Take?
The likelihood of adverse events appears to be dose-related, but there's no established threshold below which liver injury is impossible.
In one study, 5 of 16 healthy adults taking 1,500 mg/day developed ALT elevations exceeding five times the upper limit of normal.
Another clinical trial found significant enzyme elevations in 4 of 59 adults taking 300 mg/day.
More recently, a 2025 FDA-sponsored randomized trial administered 5 mg/kg/day to healthy adults for four weeks. Eight participants receiving CBD developed liver enzyme elevations exceeding three times the upper limit of normal, compared with none receiving placebo.
These participants received approximately 250–550 mg/day, although the exact doses of the eight affected individuals weren't published.
These studies demonstrate that significant enzyme elevations can occur at doses below those typically used in prescription epilepsy treatment.
What About Lower Doses?
Some evidence suggests that lower daily doses, more consistent with typical nonclinical use, may be considerably safer. The 2023 systematic review reported no cases meeting its DILI criteria among adults taking less than 300 mg/day.
A separate observational study of 839 CBD users, averaging approximately 50 mg/day, found no statistically significant increase in elevated liver enzymes compared with estimates for the general adult population.
Neither finding establishes that lower doses are completely risk-free. The number of participants taking less than 300 mg/day was relatively small, and reliably detecting rare adverse events would require studies involving thousands of participants.
Meta-analysis does not replace properly powered studies.
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Are There Any Documented Cases of Lasting Liver Damage?
CBD can cause liver enzyme elevations, sometimes severe enough to meet biochemical criteria for DILI. But few, if any, documented incidents in the clinical studies reviewed resulted in clinically apparent liver dysfunction, irreversible damage, or liver failure.
In the 2025 FDA trial, participants with significant ALT elevations did not develop clinically significant changes in liver function. Their enzyme levels returned to normal within one to two weeks after discontinuing CBD.
Similarly, the 2023 systematic review found no cases meeting Hy's Law criteria, which are used to identify potentially serious drug-induced liver injury.
However, the FDA's prescribing information for Epidiolex acknowledges postmarketing reports of cholestatic and mixed patterns of liver injury.
The evidence for reversible biochemical liver injury at clinical CBD doses is considerably stronger than the evidence for permanent liver damage from typical wellness doses.
What Should CBD Users Take Away From This?
People taking large daily doses (300–1,500 mg/day), using medications that may interact with CBD, or living with existing liver disease have particular reasons to discuss CBD use with a healthcare professional.
Liver enzyme elevations can occur without obvious symptoms, making blood testing important when evaluating potential liver injury.
At the same time, an elevated ALT result shouldn't automatically be interpreted as liver failure or permanent damage.
The appropriate conclusion isn't that CBD destroys your liver or that CBD is harmless.
We've identified a genuine adverse effect, we understand some of its risk factors, and important questions about its clinical significance remain.
About the Author
Before launching Herbal Edge, Avery Martz operated one of Idaho's largest CBD retailers, reviewing products, working with independent makers, and helping hundreds of people learn about CBD.