The scientific community often urges caution around using herbal supplements, citing the lack of long-term safety data and the risk of liver toxicity (hepatotoxicity). This warning isn’t exclusive to kava (Piper methysticum), CBD, kratom, ashwagandha. and others have faced similar scrutiny. Often, with plant-based supplements, the mechanisms behind their metabolism are not yet fully understood.
This is where the kava liver damage myth has found fertile ground. But is it true? Today, Real Botanicals discusses:
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How is kava metabolized?
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Is kava hard on the liver?
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Should kava users be concerned about liver toxicity?
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Are there reports of kava liver damage, and if so, what were the contributing circumstances?
Let's dig into the truth about kava.
First, What Is Kava? What Are the Benefits of Kava?
Traditional kava comes from the roots of Piper methysticum, a plant native to the South Pacific. It's been used for centuries in Fiji, Vanuatu, and Tonga. Kava drinks, often ceremonial, were used to make people feel more welcome, calm, and connected with others. Traditionally, the bitter roots of the kava plant are dried, ground, and used to make kava drinks.
Today, it's easy to find kava in the US or even go to a kava bar near you to enjoy the effects of kava with friends.
Kavalactones Are Where It's At!
The primary active compounds in kava are known as kavalactones. This group of psychoactive plant compounds interacts with your central nervous system, producing some pretty cool effects. Your lips and tongue get an invigorating, tingly sensation. Then, your body begins to feel more relaxed, and you may feel more comfortably chatty. The characteristic social ease is often what draws people to kava use. That, and to help ease stress.
Kava can be used in several forms, like kava tea, which is made from the powdered roots. Some people take kava pills or capsules. Others enjoy pre-measured Kava + Kratom Shots made with kava extracts.
Comparing Kava and Alcohol for Social Enjoyment
Kava does not cause chemical dependency like alcohol can, offering a non-addictive way to relax with friends. Plus, there isn't a pronounced impairment of motor skills or loss of coordination that you may experience with alcohol. But there's more to consider:
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No excessive liver enzyme induction – Kava doesn’t trigger the same liver enzyme overdrive or fat accumulation.
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No hangover – High-quality, noble kava generally doesn't cause hangovers. If alcohol makes you nauseous or sluggish, then kava may be a better choice.
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Low calorie – Kava has almost no calories or sugar. (No beer belly!)
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Less aggression – Kava promotes calmness and sociability, rather than disinhibition or aggression.
And one other biggie: Overdose and alcohol poisoning? Not with kava!
Benefits of Kava Supplementation or Kava Drinks
Kava kava supplements have been heavily marketed in the US since the 90s as an herbal supplement for stress, citing anxiolytic potential. Capsules of kava with fillers and other additives entered health food stores in the 1990s, labeled as "stress relief" supplements.
Nowadays, US kava use is returning to its roots, with more knowledgeable kava users preparing kava beverages at home. This is much more akin to the herb's traditional origins as a drink and its ceremonial history. But why do people love kava so much?
Well, it can make you feel pretty good! Warm- and fuzzy-like. People enjoy relaxing without cognitive impairment or hangovers.
Today's kava user enjoys the kava experience as a way to:
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Unwind after a long day.
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Ease nervous tension or anxiety.
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Support better sleep.
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Get a mood boost (via mild dopamine modulation).
What Are the Side Effects Related to Kava?
There are a few mild side effects linked to kava, which may worsen if you take too much at once:
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Mild gastrointestinal upset
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Skin changes (with excessive long-term use, which is referred to as “kava dermopathy”)
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Sedation or drowsiness
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Headache or dizziness (if used with other CNS depressants)
Does Kava Use Cause a Risk of Liver Toxicity?
Now, the big question: Does kava use cause liver damage? (Ah, the infamous kava liver damage myth.)
The short answer: There have been reports of liver hepatotoxicity, but these reports are rare. Most don't verify that it was the kava that caused the issue. So, consider this myth debunked until proven true.
Many kava professionals cite centuries of anecdotal evidence supporting regular use of kava without a history of documented liver toxicity, and feel this legacy is proof enough. Others want to see the lab data proving its efficacy. Proving its benefits without risk of liver toxicity, liver stress, severe liver damage, liver failure, or what-have-you.
The longer answer: Let's examine what the existing research reveals.
What Does the Current Kava Research Say?
The panic around kava liver damage emerged in the early 2000s, when a small number of healthcare professionals reported liver damage in patients who reported kava use. It was suspected that the kava use may have contributed to the liver damage. As a result, Germany and several other countries banned kava.
However, upon reviewing the case studies, some significant questions raise reasonable doubt about these conclusions. For example, some of the kava supplements used contained an array of other substances. Plus, some of the subjects were on other medications or drank alcohol in addition to kava use.
Does this mean you should ignore any potential risk of liver hepatotoxicity if you have a compromised liver function? Of course not. If your liver function is abnormal or you show signs of liver problems, any supplementation may be problematic for you, not just kava.
Kava Clinical Trials & Kava Research
Kava research investigates many aspects of kava use, not just the "kava liver damage myth". Let's take a look at some of the kava research that ties into our topic of kava and potential liver damage. It helps to know a little about how kava chemically works in the body.
Anxiolytic Efficacy
According to a 2013 systematic kava review, published by Pittler & Ernst, kava extracts were found to be significantly more effective than a placebo for reducing stressors that may lead to increased anxiety, with few adverse effects.
Findings: "The meta-analysis of three trials suggests a significant difference in the reduction of the total score on the Hamilton Rating Scale for Anxiety in favor of kava extract," demonstrating that kava extract is "worthy of consideration.
No Consistent Link Between Kava Use and Hepatotoxicity
The above-cited Cochrane Review piece by Pittler & Ernst also concluded that there was no consistent link between kava and liver toxicity in clinical settings. Until a link between kava and hepatotoxicity is proved or disproved, agencies like the WHO or the FDA will press users to be "concerned" about liver hepatotoxicity. Kava safety understanding remains, then, in limbo.
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2007 WHO report: The World Health Organization found that liver damage associated with kava was “rare” and likely linked to non-traditional extraction methods (i.e., acetone and ethanol extracts) and poor-quality material (e.g., aerial parts or moldy rootstock).
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2016 study in Planta Medica: Researchers emphasized the role of chemotypes (i.e., the specific kavalactone profile) and preparation techniques in safety outcomes (Teschke et al., 2016).
Kava originated in the Pacific Islands, so it makes sense to look there for existing research data. Since natives of the Pacific Islands have used kava for centuries, is there a history of liver damage among these long-term kava users? Turns out, there's not.
One 2020 memorandum reported findings on kava and liver damage related to dosing 100 times what's recommended for humans. It also emphasized the safety of kava relative to using only the root powders, steering clear of the flowers and aerial parts of the plant. Also mentioned, using aqueous extraction as a safer method of preparing kava products.
The "Pacific kava paradox hypothesis" postulates a puzzling observation. Despite heavy, long-term use of kava in the Pacific Islands, there hasn't been a connection to liver damage. This raises the question of why those types of reports began with users in the West, and further calls those reports into question as to their accuracy.
It's possible that Western doctors' lack of understanding of kava and how it works in the body may contribute to myths about kava use and potential risk factors.
Are There Reports of Liver Damage Due to Kava Use?
Yes, but they are rare and largely involve extenuating factors.
A 2011 analysis by the Food and Agriculture Organization (FAO) found that, out of over 100 case reports, fewer than 10 demonstrated plausible causality.
Extenuating Circumstances
Nearly all 10 of the above-mentioned cases had extenuating circumstances contributing:
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Non-traditional ethanol-based extracts
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Poor manufacturing practices
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Concurrent alcohol or medication use
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Pre-existing liver disease
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High, chronic doses beyond traditional use
Is the Kava Liver Damage Myth Debunked?
It depends on who you ask.
In nearly every confirmed case, complicating factors played a key role. Therefore, it's easy to see why using high-quality, lab-tested kava root, as directed, should be less worrisome. Still, discussing your kava use with your doctor may provide valuable insight into the safety of kava for you.
Meanwhile, we wait for more conclusive scientific evidence.
How Kava Is Metabolized?
Everything we ingest is processed by the liver. Your liver produces substance-specific liver enzymes to aid in its metabolism. This includes pharmaceuticals, alcohol, caffeine, and herbal supplements like kava. For kava, these metabolic pathways are not well-studied, leaving its potential risks for liver hepatotoxicity or liver stress largely unknown.
Kava is primarily metabolized in the liver through the cytochrome P450 (CYP450) enzyme system. The same enzymes that metabolize a large percentage of pharmaceutical drugs are utilized: CYP1A2, CYP2D6, and CYP3A4.
Liver Enzymes and Kava Metabolism
Kavalactones such as kavain and yangonin are fat-soluble. This means that the kavalactones:
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Absorb better when taken with dietary fats (like coconut milk or avocado).
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Tend to accumulate in fatty tissues in the body.
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They are not easily excreted in urine, unlike water-soluble compounds.
The kavalactones you ingest pass through the liver via phase I and phase II biotransformation, involving oxidation and conjugation. If the liver is already burdened due to alcohol, fatty liver, or medications, this can slow detoxification and increase the risk of side effects.
Additionally, kava may inhibit CYP450 enzymes. This means it may interfere with the metabolism of other substances. This is why it's important to use caution and speak with your doctor if you are on prescription drugs or if you drink alcohol.
Signs of Liver Problems
If you're using kava regularly, it’s smart to know the early signs of liver distress:
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Yellowing of the eyes or skin (jaundice)
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Unusual fatigue or weakness
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Dark urine or pale stool
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Upper right abdominal pain
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Persistent nausea or loss of appetite
While these symptoms could occur with other conditions, if you notice these signs with regular kava use, it's recommended that you bring them to your doctor's attention and follow their medical advice.
Frequently Asked Questions About Kava and Liver Damage
Is kava safe?
The safe use of kava has been going on for centuries. This is why so many people trust and use kava. The quality of kava you use matters. Use only high-grade, lab-tested kava that you buy from reputable companies.
Can kava cause liver damage?
Kava consumption is still overshadowed by fears of potential liver toxicity, even though current scientific research has not shown this to be a very valid concern. Some reports have suggested kava use may be linked to liver issues, but those cases were rare and had extenuating circumstances. That said, use caution if you drink alcohol, take medications, or have a compromised liver function.
What's the dosage for kava? How much kava should I use?
If you're using the powdered root of the Piper methysticum plant, the different kava species may be different strengths (and therefore hard to gauge dosage). But if you buy kava powder or capsules, you can be mindful of your dosing, which is generally considered safe at less than 300mg of kavalactones per day. Even better, use pre-measured kava—like our kava kratom shots!
Should I ask my doctor before I take kava?
If you're worried about your liver cells, consult with your doctor or holistic healthcare provider. Discuss your current medications and any liver conditions or family history of liver disease. You can also request baseline liver enzyme testing and repeat that periodically to monitor liver health.
What kind of kava should I buy?
Lastly, shop for kava online, or buy it in store, but ONLY buy high-quality kava! High-quality kavas will be labeled "noble" varieties and will be lab-tested for purity. Buy from brands like Real Botanicals that test all their products for mold, heavy metals, and chemotype profile.
Using Kava Safely for Wellness & Enjoyment
Current research suggests that moderate use of good-quality kava is unlikely to cause liver damage in healthy individuals. In rare cases of liver toxicity, there was a combination of factors that may have contributed, like kava mixed with other substances, used alongside heavy alcohol use, or in cases of pre-existing conditions, such as a compromised liver function.
Kava liver damage myth debunked? Based on current kava research findings, we think so. With safe kava use, mindfully and moderately, kava can be a great way to unwind!
So sit back, sip, unwind, and shop all Real Botanicals products today!