Skip to main content

Is Kava Safe? Possible Interactions, Risks, and Side Effects

By January 22, 2020No Comments

Kava tea (aka kava kava) is a popular drink. It’s been consumed for centuries (millenia, really!) in the Pacific Islands, and now it’s becoming increasingly common in the United States where kava bars are popping up left and right across major cities.

People love kava for its calming effects. It appears to be a great alcohol alternative, which makes it a wonderful libation in social settings as well as a relaxing drink at the end of the dat or before bed.

But is kava safe?

That’s the real question. Because despite any benefits (like calming, sleep benefits, etc.), you must weigh any potential risks, side effects, or possible interactions against those benefits.

With kava, the case isn’t necessarily straightforward.

Is Kava Safe?

Here’s the quick answer: kava kava is probably safe for most people, but there may be edge cases and issues to worry about. 

The main concern with kava is with its potentially adverse effects on the liver. There have been cases, though seemingly quite few, where kava has been associated with pretty serious liver issues, including liver failure. 

However, there seems to be some controversy on the causal pathways and direct relationship between the two. We’ll cover that in a later section.

With regards to kava safety, what we really want to cover is three things:

  1. Kava side effects (common and uncommon)
  2. Kava and the liver
  3. Kava and interaction effects

We’ll cover each of these sections in detail, and then we’ll summarize the pros and cons at the end so you can make your own decisions when it comes to consuming kava.

1. Kava Side Effects

Kava kava can be consumed in tons of different ways. You can pop a capsule, throw the extract into a smoothie, eat kava candy, or, more commonly, drink some soothing kava tea. Regardless of the format, kava has some noticeably positive benefits, including:

  • Quells anxiety and stress
  • Helps sleep
  • Muscle relaxation
  • Works on dopamine system to provide euphoria or a sense of well-being

All of this makes the plant quite popular as an alcohol alternative, or just to relax and hang out after a long day.

In addition to the positive effects, people do sometimes report some negative side-effects:

  • Kava can lead to dry, itchy, and scaly skin if consumed in very large quantities
  • Nausea is one of the more common negative side effects
  • Weight loss has also been reported
  • Apparently large quantities have also been associated with impotence and a lowered sex drive

There’s also a big list of side effects on RxList including things like ‘blood in urine’ and ‘facial puffiness’, though genuinely I cannot find where they are getting their data or what the quantity of people reporting those side effects is. Personally, having drunk kava tea, I can understand nausea, but the list on RxList is quite strange to me. I’d take it with a grain of salt.

Again, the big “side effect” is kava’s potentially dangerous link to liver damage. This is a complicated issue that is still not well understood, but we’ll try to summarize the research and thoughts here as well as we can.

2. Kava and the Liver

Here’s where it all started: In 2007, a panel from the World Health Organization (WHO) reported a potential link between kava and seven deaths and 14 liver transplants throughout Europe.

In the report, however, there was no strong and clear conclusion. In fact, there was a caveat – a potential idea – that liver damage may only happen in kava beverages formulated with the whole kava kava plant instead of just the root. Additionally, it may be when the manufacturer used acetone and ethanol to extract the kavalactones from the kava plant instead of water.

I’m not here to hypothesize further, but suffice to say, there are some really interesting questions around the issue of liver toxicity. 

On a more philosophical angle with regard to risk analysis, the fact that Pacfic Islanders have been drinking kava drinks for centuries (millenia!) with no evidence of liver damage is, at the very least, quite interesting. They tend to make the drink with water and with the root (re: the above paper’s hypothesis on the construction of the beverage being a cause).

It also may be that the product’s quality isn’t very good. That’s one huge issue and why it’s so important to buy quality products. 

Quality products and production process aside, some studies have also found a solid “association between heavy consumption of kava and increased levels of a liver enzyme that suggests the flow of the liver’s bile might be affected.” However, when kavalactones (the active ingredient) were tested in rat studies, there were no signs of liver toxicity even at high doses.

Confusing stuff, right?

Here’s the summary from a great Reddit thread that I tend to find reasonable:

“So the answer to your question about is kava bad for your liver? No if you are consuming the appropriate kava product from a trusted vendor. You have to be careful with whom you buy from and what form of kava you buy. Kava extracts, tinctures, anything with alcohol derived kava extract is a definate NO NO Buying kava powder is good (medium grind, micronized, instant kava) but buy from a trusted vendor who knows about their product, has good quality control and is knowledgable about kava.”

So buy the good stuff, and for god’s sake, consume in moderation!

One more note on risk: apparently the baseline is quite low, even factoring in the potential causal link between kava and liver damage above. Basically, The National Library of Medicine said the following: 

“Based upon reported cases, the estimated frequency of clinically apparent liver injury due to kava is less than 1:1,000,000 daily doses. However, spontaneous reporting is believed to capture less than 1% of severe adverse events from the use of dietary supplements. Between 50 and 100 cases of clinically apparent liver injury have been published or discussed in the literature.”

Hopefully you’ve got a better understanding of the nuance we’re dealing with here. The decision to consume kava, at least at the present moment, is going to come down to your own research, decision making, and risk profile. For what it’s worth, I choose to drink it every once in a while but I’ve made the decision through lots of research and trial and analysis. You should do the same.

3. Kava Interaction Effects

At a high level, you can use some simple heuristics to figure out what to avoid when taking kava. Obviously, since kava has a calming/sleep promoting/downer/anxiety reducing effect, it’s probably smart to avoid other substances that have similar effects. Of course, this includes alcohol, but also, prescription drugs like Xanax should definitely be avoided.

In essence, my strategy here is to avoid any other mind altering substance. Why risk weird interaction effects? If you’re drinking kava, drink kava. 

The technical answer here (from WebMD) is that there are some very clear interactions. Major interaction effects (definitely avoid) come from:

  • Alprazolam (Xanax)
  • Sedative medications (CNS depressants)

Moderate interaction effects (be cautious):

  • Levodopa (kava may reduce the effects of Levodopa)
  • Medications changed by the liver (lozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline, zileuton (Zyflo), zolmitriptan (Zomig), amitriptyline (Elavil), clomipramine (Anafranil), cyclophosphamide (Cytoxan), diazepam (Valium), lansoprazole (Prevacid), omeprazole (Prilosec), lansoprazole (Protonix), phenytoin (Dilantin), phenobarbital (Luminal), progesterone, amitriptyline (Elavil), diazepam (Valium), zileuton (Zyflo), celecoxib (Celebrex), diclofenac (Voltaren), fluvastatin (Lescol), glipizide (Glucotrol), ibuprofen (Advil, Motrin), irbesartan (Avapro), losartan (Cozaar), phenytoin (Dilantin), piroxicam (Feldene), tamoxifen (Nolvadex), tolbutamide (Tolinase), torsemide (Demadex), warfarin (Coumadin), and others.)

That list of meds that affect the liver is wayyy bigger, so keep it safe and just don’t mix things unnecessarily. Read the label. Ask your doctor. Do your due diligence. 

Summary: Is Kava Safe?

Kava kava is popular and has been consumed for millenia. Clearly, then, for the large majority of people, there aren’t any significant problems or dangers.

However, there is some murkiness around the preparation and quality of certain kava products as well as the general effects of kava on the liver (especially when mixed or combined with other substances).

The summary here is that it’s most likely going to be pretty safe as long as you do your due diligence, buy quality products, consume in moderation and without mixing other substances, and make sure you don’t have any conditions that would make it dangerous for you to consume kava.

Leave a Reply