CBD and the Liver: Storm in a Dropper Bottle?
A science-backed, soul-searching look at liver enzymes, CBD fearmongering, and what the data actually says about safety
“Liver enzymes are up. Cue the outrage.”
—Modern media, probably
The Cannabidiol Curveball No One Saw Coming
July 7, 2025. JAMA Internal Medicine drops a tightly designed, placebo-controlled, double-blind trial titled:
“Cannabidiol and Liver Enzyme Level Elevations in Healthy Adults: A Randomized Clinical Trial” by: Jeffry Florian, PharmD; Pablo Salcedo, PhD; Keith Burkhart, MD; Aanchal Shah, PhD; Lakshmi Manasa S. Chekka, PhD; Dro Keshishi, PhD; Vikram Patel, MD; ShanChao Yang, MD; Melanie Fein, MD; Ryan DePalma, MD; Murali Matta, PhD; David G. Strauss, MD; Rodney Rouse, MD. (Here’s the PDF)
The premise? Measure liver enzyme elevations in healthy adults taking high doses of pharmaceutical-grade CBD isolate (up to 1600 mg/day) over 28 days.
The outcome? Some enzyme elevations—ALT and AST primarily—but no symptoms, no liver damage, and all values returned to baseline once CBD was stopped.
That’s it. That’s the study.
But here’s the kicker: the internet (and eventually the media) is about to lose its collective mind.
So before we all run for our milk thistle, let’s pause. Breathe. And take a grounded look at what this trial shows, what it doesn’t, and why a liver enzyme blip isn't the same thing as liver doom.
Have you heard friends or colleagues raise concerns about CBD and liver safety? Drop your thoughts or questions below. I read every one.
What the Study Got Right
This trial wasn’t vague, retrospective, or pulled from the back of a marketing deck. It was rigorous. 201 healthy adults. Blinded. Randomized. Dosed under supervision.
And unlike past studies that leaned heavily on self-report or murky exposure, this one gave participants real CBD, in real doses, every day. Twice daily, in fact.
The result? In the CBD group:
9.1% had elevated ALT, a key liver enzyme
5.6% exceeded 3x the upper limit of normal
0 participants in the placebo group had these elevations
0 participants had symptoms
All elevations resolved after stopping CBD
That last point matters. No signs of injury. Just enzyme shifts.
So what does that mean? In pharma speak: a signal. Not a sentence.
⚠️ Question to Consider: If a healthy person takes 1600 mg of anything per day—shouldn’t we expect the liver to respond somehow?
What the Study Didn’t Do
This trial isn’t a referendum on all CBD.
It studied high-dose, purified isolate CBD—not the kind you find in your corner-store gummies or balanced tinctures with terpenes and other cannabinoids.
And it focused on healthy adults, not people with chronic inflammation, autoimmune illness, or polypharmacy.
So no, the findings don’t tell us what happens with:
Full-spectrum oils
Topicals or vapes
Microdoses
Patients with underlying liver disease
Or those combining CBD with other liver-metabolized meds
That’s not a flaw—it’s just the limits of the design. But it also means we shouldn’t leap from “this happened in a stress-test model” to “CBD is hepatotoxic.”
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The Big Misunderstanding
Liver enzymes are not binary death flags. They're early indicators, like a car’s check engine light.
And in real-world medicine, dozens of medications—from acetaminophen to antibiotics to statins—raise liver enzymes transiently without causing damage.
In fact:
About 10% of healthy adults in any drug trial show minor liver enzyme bumps
Tylenol is still the #1 cause of acute liver failure in the U.S.
But we don’t ban it—we just dose it wisely and warn people with liver issues
CBD deserves the same treatment.
🤔 Question: Should our safety standards be tighter for natural substances—or more forgiving?
How This Compares to Other Liver Risk Meds
The rates of liver enzyme elevation from high-dose CBD in this study (~5–9%) are on par with many other FDA-approved medications.
Consider:
Isoniazid: Used for tuberculosis, causes elevated liver enzymes in 10–20% of users
Statins: 3–5% have ALT/AST elevations
Methotrexate: A mainstay in autoimmune care—known to stress the liver over time
Even NSAIDs, like ibuprofen, can cause hepatotoxicity with long-term or high-dose use
Yet all of these remain available because we’ve learned how to monitor, dose, and counsel patients.
Why treat CBD differently?
🔗 on CED Clinic: CBD Products, Ranked by Potency
What This Means for Patients
If you’re using moderate doses of full- or broad-spectrum CBD under medical guidance—this trial likely doesn’t apply to you directly.
But it does reinforce some commonsense principles:
Know what’s in your product
Don’t exceed necessary doses
Monitor labs if you’re taking CBD daily and/or with other medications
Work with someone who can interpret changes meaningfully—not panic
For healthy folks? Mild enzyme bumps aren’t surprising. For those with liver disease or complex regimens? Get checked and stay smart.
And for everyone else?
Anticipating the Alarmism: The Headlines Are Coming
Here’s what we’re about to see in the media:
“New Study: CBD Can Harm Your Liver”
“CBD Not So Safe After All, Warn Experts”
“Time to Rethink Your Gummies?”
Here’s what to remember:
The study didn’t show injury, just lab changes
It used pharmacologic doses
All elevations reversed
It wasn’t about consumer-grade products
There’s zero evidence from this study that low-dose CBD causes harm
This is where responsible coverage matters. Sensationalism helps no one—not consumers, not clinicians, not policymakers.
Want More Clinical Depth?
This Substack is the conversational sibling. For the science-forward deep dive, clinical comparisons, and more extensive FAQs, read the full piece at CEDclinic.com. I pulled no punches there—and explained every acronym, stat, and implication.
👉 The CED Clinic Blog: So Much More To Say
🧠 Go there if you want a whole hub of Doctor-Approved knowledge, more stats, source citations, or extended commentary on the study's design. And hundreds more. All free.
Prefer over-arching knowledge, want a one-stop shop to understand cannabis care, the benefits and practical uses of cannabis: Doctor-Approved Cannabis Handbook
🧀 Let’s Make This Fun:
Why did the CBD bottle get kicked out of med school?
Because it raised too many eyebrows… and ALT levels.
Why did the liver file a complaint against CBD?
It felt a little “elevated” without consent.
If CBD is dangerous because it moves your liver enzymes, then kale should come with a surgeon general warning for causing kale-induced flatulence. Let’s keep the fear-mongering in aisle five.
High-dose CBD causing enzyme bumps is like blaming an espresso shot for causing heart palpitations—when you drank the whole pot.
🎤 A Thought:
If Tylenol is still on shelves, CBD deserves a trial—just not by public opinion jury with pitchforks and half-read headlines.
💬 Drop a comment if you’ve changed your view on CBD safety.