Worried About CBD Hurting Your Liver? Here’s What the Experts Have to Say
Share on Pinterest A new study draws attention to potential risks of CBD. Getty Images
- A new study shows evidence that extremely high doses of CBD can be damaging to the liver.
- But experts say this research, which was done in mice, is still in the early stages, and more information is needed.
- CBD isn’t regulated by the Food and Drug Administration, but the agency has been cracking down on companies claiming certain health benefits from taking CBD.
The market for products containing cannabidiol (CBD) — the non-psychoactive, pain-relieving chemical in cannabis — has exploded in recent years, but the product is still relatively understudied.
That’s drawn scrutiny from the Food and Drug Administration (FDA) and other regulators as manufacturers make claims on their CBD products that aren’t necessarily backed by science.
Now, a recent mouse study has been making headlines for the findings that taking too much CBD might lead to liver damage in high enough quantities.
Should you be worried? We took a look at the study and talked to experts about what this mouse study can mean for human fans of CBD.
Citing a “lack of comprehensive toxicological studies devoted to CBD safety that are critical for further marketing of CBD and CBD-containing products,” researchers from the University of Arkansas investigated the effects of treatments of various doses of CBD on a group of 8-week-old mice.
While the mice largely tolerated the CBD, those given the highest doses — a human equivalent to 200 milligrams (mg) of CBD — showed clear signs of liver toxicity, the researchers found.
In addition, repeated doses of a smaller amount of CBD — the human equivalent of around 50 mg — also showed signs of liver swelling and damage.
“Although (a dose of) 200 mg is not applicable to most real-life scenarios, it does provide critical information regarding the potential consequences of CBD overdose as well as for doses needed for further subchronic and chronic toxicity studies,” the authors, publishing in the journal Molecules, wrote.
That sounds potentially dangerous, but most experts say there’s no need to panic just yet.
While experts point out patients need to be informed about what they’re getting and what the risks can be, the amount of CBD the animals were exposed to is far higher than what most humans would take.
Dr. Diana Martins-Welch, attending physician in palliative medicine at Northwell Health in New Hyde Park, New York, says even though CBD is ubiquitous, it does “not mean it is safe to take in high quantities, or that it is more effective at high doses.”
“Many people know that taking too much ibuprofen or Tylenol can have detrimental consequences. CBD is no different. Generally speaking, therapeutic CBD doses range from 0.5 mg/kg/day to 20 mg/kg per day,” Martins-Welch explained. “This study in mice used significantly higher doses of CBD than what is usually taken for therapeutic benefit in humans.”
She points out the study shows how — similar to other medications — people need to be careful if they consume high doses of CBD.
“Caution must also be taken when trying to translate the results of this animal study to humans,” Martins-Welch said. “Bottom line: Therapeutic-range CBD is generally safe. Toxicity at high doses is a concern, as is the case with most other medicines.”
Dr. Thinh Vo, director of quality and compliance at Koi CBD, a purveyor of lab-certified CBD products, says CBD users need to remember mice and people are pretty different.
“Mice and humans may share virtually the same genes, but we are different physiologically,” Vo told Healthline.
In addition, he said, “Extrapolation of this research shows no negative effects on a human at the recommended maximum daily dosage of 20 mg/kg.”
And even that is extreme, says Jason Cohen, founder of the CBD company Tesséra Naturals.
“A big caveat to this study is that the mice were given doses that were the human equivalent to the maximum recommended dose of the drug Epidiolex, which is a specific prescription drug meant to treat seizures,” he said.
“To put that in perspective, that would be over 1,300 mg of CBD per day for an adult weighing 150 pounds! This is much higher than the typical daily dose of casual CBD oil users. Most people stick to somewhere in the range of 10 to 80 mg per day, with slightly higher doses for insomnia, therapeutic effects, and flare-ups,” Cohen said.
So, sticking to the right dose appears to be safe for the time being. But that doesn’t mean CBD users are completely risk-free.
There’s no federal regulation for many CBD products sold OTC, so you may be taking more or less of the substance than is advertised on a product.
In the last few years, the FDA has sent a slew of warning letters as a result of CBD products being sold with either inaccurate levels of the compound that didn’t match what was listed on the packaging or for containing trace amounts of THC, the psychoactive compound in cannabis and a Schedule 1 drug.
“Furthermore, a recent independent analysis performed by ConsumerLab.com revealed that CBD doses in commercially-available products ranged from as little as 2.2 mg to as much as 22.3 mg, further amplifying concerns of potential toxicity,” the study authors noted.
Other studies have corroborated this issue.
A recent report by cannabis testing lab CannaSafe to California’s Bureau of Cannabis Control (BCC), for example, stated that somewhere between 69 and 80 percent of CBD products failed to make label claims.
What the CBD market needs is “accreditation for all tests and traceability and introduction of stability testing and shelf labeling like the FDA requires for all food products and supplements,” the company told Healthline via email.
They point out that the BCC in its capacity as a state regulator of cannabis products has already made them measurably safer. Under the bureau’s oversight, contamination of pesticides in cannabis products fell from 25 percent to under 5 percent.
While the headline-maker of the University of Arkansas study revolves around overall liver toxicity, the research highlights another little known problem with CBD: It has the potential to negatively interact with other prescription drugs.
“Our liver has a family of enzymes called cytochrome P450, which break down drugs into smaller bits that allow our cells to absorb them better and eliminate them properly,” Cohen said.
“Although the effects have been shown to be minimal, if you take high enough amounts of CBD, it can inhibit the CYP450 enzyme’s ability to metabolize certain pharmaceutical drugs,” he said.
While the FDA works on improving its oversight and regulatory structure, the best thing a consumer CBD user can do is buy from a marketplace that offers transparent laboratory testing, possibly favoring states that already have firm CBD regulations in place — and to use the products in moderation.
Is CBD Legal? Hemp-derived CBD products (with less than 0.3 percent THC) are legal on the federal level, but are still illegal under some state laws. Marijuana-derived CBD products are illegal on the federal level, but are legal under some state laws. Check your state’s laws and those of anywhere you travel. Keep in mind that nonprescription CBD products are not FDA-approved, and may be inaccurately labeled.A recent mouse study found taking too much CBD might lead to liver damage in high enough quantities. Should the casual CBD user worry?
Is cbd oil bad for your liver
With CBD usage booming across America, there has been concern about possible health and safety risks. One recent study, in particular, garnered alarming headlines about the dangers of CBD to the liver. In the study, scientists gave mice high to extremely high doses of CBD and studied the effects on their health. While the study did show that extreme doses of CBD can be damaging to the liver, the news coverage tended towards alarmism, failing to put the study into perspective.
Like any supplement or medication, CBD does have risks, including dose-dependent risks to liver health. However, while users at the high end of the dosing spectrum should have their liver enzymes monitored, for the vast majority of users, the product is very safe. Here’s what you need to know about CBD and liver function.
The CBD Mouse Liver Study
A study published in 2019 measured CBD hepatotoxicity (i.e. liver damage) in 8-week-old mice, as a way to model the possible effects on human livers. Scientists used two ranges of doses: one group was subject to enough CBD to cause damage in a single dose — called acute toxicity — while the other group was exposed to ongoing lower, or “sub-acute” doses. The acute toxicity group was given doses from 246 to 2460 milligrams per kilogram of weight, while the subacute group received daily doses from 61.5 to 615 mg/kg daily for 10 days.
The mice given the highest acute dose showed evidence of liver damage within 24 hours. Similarly, 33% of the mice on the 615 mg/kg dose became sick after only two doses, and 75% of the mice at the highest sub-acute dose were extremely sick or dead within 3-4 days. However, the mice at the two lowest doses (61.5 mg/kg and 184.5 mg/kg) showed “no visible signs of toxicity.”
So how much should you worry? Unless you have existing liver damage or are taking extremely high doses of CBD, probably not much.
CBD, Dosage and the Mouse Study
It’s a basic principle of toxicology that the dose makes the poison. There’s no substance on earth that you can have in literally unlimited amounts — even too much water can kill you — indeed, it has happened to soldiers and athletes who drink too much while trying to avoid dehydration.
The question isn’t whether CBD can harm your liver — an extremely high dose can and will. The question is whether CBD will harm your liver at the doses you are taking. And for the vast majority of CBD users, that’s very unlikely.
To understand how the CBD mouse study translates to humans, we need to do a little math. The average weight for an American is about 76 kg for women, or 89 kilograms for men (dosage is given in metric units, so we’re using kilograms instead of pounds.) To get the smallest dose used in the mouse study (which was not found to be toxic), we multiply 61.5 mg/kg by the average weight of an adult. For women, to get an equivalent dosage, they’d have to consume 4,674 mg of CBD per day. For an average man, the number is even higher — 5,473.5 mg.
If you consumed ten 15 ml bottles of Papa & Barkley CBD Hemp Drops in a single day (WHICH YOU DEFINITELY SHOULD NOT DO!) you still wouldn’t quite have enough to match the dose. And that’s the lowest quantity, which again was not shown to be toxic in the short term.
Additionally, depending on your method of consuming CBD, it may not need to be processed by the liver at all.
CBD Dosage Method and the Liver
One aspect of CBD liver effects that the study does not address is the way CBD is processed by the body. According to Dr. Patrick Byrne, a physician who prescribes cannabis to some of his patients, the liver is only involved when CBD is consumed through the stomach — by eating it or swallowing tinctures.
However, other methods of CBD consumption don’t involve the liver, because the CBD goes straight into the bloodstream. When you consume a tincture sublingually (by holding it under your tongue for a minute), the CBD bypasses the liver entirely by absorbing into the blood vessels under your tongue. A tiny bit may be swallowed, but the vast majority will not enter your stomach. Similarly, if you smoke or vaporize cannabis, the CBD will be absorbed through your lungs, leaving your liver out of the process.
Additionally, these methods will improve cannabis bioavailability ; more of the CBD will be absorbed into your bloodstream, and the absorption will happen more rapidly. The reason for this is that stomach acid tends to destroy much of the CBD. The exact amount absorbed varies from person to person, but according to Dr. Byrne only about two percent of the CBD consumed orally typically makes it into your bloodstream.
With smoking or vaping, the rate is much higher — roughly 35-40% reaches your veins directly. Tinctures are also more effective than oral consumption, resulting in about 20% absorption rate.
However, the highest absorption rate is when the drug is administered rectally, through a CBD suppository. It’s perhaps not the most enjoyable way to use CBD, but for illnesses like Crohn’s, IBS, ulcers and other digestive diseases, the CBD will give you the most effective anti-inflammatory effects using this dosing method. Rectal absorption rates for THC are around 70-80 percent , and it’s believed that CBD has a similar rate of absorption. Similar to vaping, smoking and sublingual absorption, rectally administered CBD bypasses the liver entirely.
So does that mean you should avoid CBD edibles for the sake of your liver? Not at all! While it’s important to understand all the risks of a medication, for most CBD patients the risk of liver damage is very low — often significantly lower than traditional medicine such as painkillers used to treat the same conditions.
Understanding CBD Liver Risk
That isn’t to say CBD at normal doses doesn’t present some risk to the liver. For people with very serious epilepsy or pain conditions requiring high doses of CBD, there is a risk. In clinical studies of Epidiolex , a prescription CBD extract used to treat epilepsy, nearly 16% of users had elevated liver enzymes, which can indicate stress to the liver and can be a warning sign of toxicity.
However, those incidents were dose-dependent. At its high end, Epidiolex dosage may be as high 20mg/kg twice a day, which translates into an average daily dose of 3,040 mg for women, or 3,560 mg for men. That’s many times the typical dose most CBD users take. For example, for a man weighing 175 pounds (about 89 kg), Papa & Barkley recommend a maximum dose of 350 mg for treating chronic pain or epilepsy.
Additionally, CBD is often used as an alternative to other drugs with greater risks, such as opioids, which have severe risks including addiction, overdose, and liver damage. Even over the counter painkillers like acetaminophen increase risks of heart attacks, kidney and liver failure, stomach bleeding and death. While CBD is not without its own risks, the risk is often lower than conventional medication.
The Bottom Line: Monitor Your Health, But Don’t Panic
Every medication has risks. In the case of CBD, high doses, existing liver damage, and drug interactions can compound those risks. You should consult your doctor before trying CBD, and monitor liver enzymes if you’re at risk. However, for most patients, CBD is a safe supplement with very low risks of liver damage or other harmful health effects.
Recommended CBD Products:
Kushy CBD – Gel Capsules
These full-spectrum CBD capsules are made with high-quality, non-GMO cannabis, fortified with Omega 3, Omega 6 and GLA. The capsules are tested by a 3rd party lab, for a high-quality product with dependable dosing.
CaniBrands – Can I Sleep Sublingual Oil
CaniBrands Can I Sleep oil is the perfect supplement for gentle sleep support, without dependence. The hemp-derived CBD is complemented with melatonin, to help you maintain a regular sleep cycle, and wake up refreshed. Medium Chain Triglyceride Oil (MCT) helps the tincture absorb quickly under your tongue, for a quick and effective bedtime aid.
Elixinol CBD Powder 21 Pack – Mixed Flavors
This drink powder pack contains 21 single-serving sachets in three different formulations, for support throughout the day. Special terpene profiles energize you in the morning, support workout and stress recovery later in the day, and finally help you achieve rest, relaxation and a full night’s sleep in the evening. This powder is great for high-performance lifestyles, enabling you to charge up with a flavorful drink on the go.
Bloom Farms – Blackberry CBD Mini Vapor Pen
This high-quality CBD vaporizer combines the rich scent of sun-ripened blackberries with the healing power of cannabinoids. The pen provides 250 mg of CBD, combined with other cannabinoids, such as CBD, CBC, CBG, and CBN, for a powerful entourage effect. The vape is made with best-in-class hardware, and is easy to use — just inhale for a quick dose of CBD whenever you need it.
Medical marijuana aka. cannabis should be used under the direction of a licensed healthcare provider. This site is intended for adults and legal medical marijuana patients and contains links to products we sell on our marketplace.Is CBD a safe supplement, or could it be putting your liver in danger? Here’s what you need to know about CBD and liver function. ]]>