The effects of kava and kava side effects depend on such factors as the type and strength of the cultivar and the method of preparation. Generally, kava is known for its relaxing properties and ability to induce sociability and a feeling of harmony without diminishing mental clarity or awareness. For many users, kava is a pleasant, slightly stimulating drink that relieves fatigue, relaxes the body after hard work or effort, clarifies the mind and brings a sense of well-being. As noted by an early kava researcher, L. Lewin in 1927 (whose accounts can be read in Dr Lebot’s famous book “Kava: The Pacific Elixir: The Definitive Guide to Its Ethnobotany, History, and Chemistry”):
When the mixture is not too strong, the subject attains a state of happy unconcern, well-being and contentment, free of physical of psychological excitement. At the beginning conversation comes in a gentle, easy flow and hearing and sight are honed, becoming able to perceive subtle shades of sound and vision. Kava soothes temperaments. The drinker never becomes angry, unpleasant, quarrelsome or noisy, as happens with alcohol. Both natives and whites consider kava as a means of easing moral discomfort. The drinker remains master of his conscience and his reason. When consumption is excessive, however, the limbs become tired, the muscles seem no longer to respond to the orders and control of the mind, walking becomes slow and unsteady and the drinker looks partly inebriated. He feels the need to lie down. (…) The drinker is prey to exhaustion and feels the need to sleep more than any other sensation. He is overcome by somnolence and finally drifts off to sleep.
According to another scholar: Kava makes you quiet and able to think and listen to your thoughts. Your mind opens to what has been and should be done. The subjective feeling after kava is to be slowed down, for it almost forces one to become quiet. Sometimes it is like entering a light relaxed dream. Some describe the kava state of consciousness as like looking into a mirror. One’s mind goes beyond one’s body and looks back. The altered state of consciousness is subtle and mild. Noise, interference with thought processes, bright lights, movement, all hinder the effect, the mildly altered stream of thought. The subdued effect is maintained only if there is peace and quiet.
Many people like to compare drinking kava to the opposite of drinking coffee. Both are used as social drinks. While the latter can give a mild buzz and “kick” of energy, the former is known for its gentle calming and relaxing effects. With little kava side effects.
Noble kava roots have been used safely, often on a daily basis, by millions of people for centuries or even millenia. In fact, kava has been traditionally used around the Pacific as a remedy for numerous health problems. Recent scientific studies (such as the one conducted by the University of Melbourne) and publications also confirm the safety and suggest potential benefits of using pure, noble kava roots. As noted by the World Health Organisation in their latest (2016) report on kava:
On balance, the weight-of-evidence from both a long history of use of kava beverage and from the more recent research findings indicates that it is possible for kava beverage to be consumed with an acceptably low level of health risk.
Kava’s safety was also confirmed in a comprehensive report (2004) prepared by Food Standards Australia New Zealand:
The available data indicates that traditional kava beverage prepared from the root has a long tradition of safe use in the South Pacific Islands. It is compositionally different from kava products prepared by extraction using organic solvents. While excessive consumption of the traditional kava beverage may lead to adverse health effects, such as kava dermopathy, there is no evidence that occasional use of kava beverage is associated with any long-term adverse effects, including effects on the liver.
While some older reports expressed concerns over kava’s potential for causing liver injury the quality of these reports has been criticised by a number of scholars who noted that:
A detailed examination of the cases revealed a majority of reports that can be much more easily explained by known adverse effects of documented co-medications or alcohol abuse rather than by potential hepatotoxic effects of the kava preparations themselves.
According to more recent studies and publications, such as the paper prepared for the Codex Alimentarius Commision:
Kava has had at least a 1500-year history of relatively safe use, with liver side effects never having arisen in the ethnopharmacological data. (…) Clinical trials of kava have not revealed hepatotoxicty as a problem. This has been confirmed by further studies evaluating the toxicology of kava drink. Based on available scientific information it can be inferred that kava as a traditional beverage is safe for human consumption.
This view is echoed in a comprehensive scientific literature review by Showman et al. (2014):
Only a fraction of the handful of cases reviewed for liver toxicity could be, with any certainty, linked to kava consumption and most of those involved the co-ingestion of other medications/supplements. That means that the incident rate of liver toxicity due to kava is one in 60- 125 million patients [note that many of these users have likely consumed non-noble and impure kava products that have a recognised higher potential for causing adverse reactions]. For Pacific traditional users, despite the much higher kavalactone exposure, [kava] liver toxicity is either unheard of or unreported.
Similarly, the New Zealand Association of Medical Herbalists (NZAMH) observed that:
Recent reviews on kava hepatotoxicity by a number of prominent toxicologists, hepatologists and medical herbalists all conclude that the incidence of this problem is extremely rare. (…) A comparison with paracetamol-associated hepatotoxicity, results in the conclusion that these potential risks for kava are dramatically less than that of a popular non prescription drug widely sold through grocery outlets.
In other words, while the potential for adverse reactions in some users cannot be completely excluded, kava is seen as vastly safer than common pain killers, not to mention many prescription medicines or New Zealand’s most popular drug: alcohol, which is a widely known dose-dependent liver toxin that can also cause many other adverse health effects never associated with kava use.
However, while the safety record of traditional forms of pure, noble kava roots appears to be well-established, you need to be aware that not all kava products sold through health food shops are noble, pure or traditional. Some vendors have been found to sell kava root powders containing the potentially harmful aerial parts of the plant (unlike pure kava roots, the never-traditionally consumed aerial parts of kava contain a mildly toxic alkaloid pipermethystin) or unsuitable, non-noble (tudei, medicinal or wild) kava varieties which are known for sometimes causing adverse side-effects (read more about these varieties and the differences between them and noble kavas here). As noted by Dr Lebot:
In the case of kava, the determination of suitable qualities is reflected by the secular experience in the Pacific. In this region, experience tells that noble cultivars are safe and deliver the appropriate physiological effects with no hang-over. However, experience with two-days cultivars, indicates that they might possibly be connected with observations of liver toxicity.
This view is supported by a recent publication by Schmidt et al. (2015) who argue that the use of non-noble varieties in the production of kava-based supplements could at least partially explain the rare cases of adverse health reactions among Western consumers and the lack of any significant health problems among those who regularly consume noble varieties “known to be safe through centuries of traditional experience” Furthermore, some companies offer kava-extracts produced with the use of strong non-polar solvents that extract far more compounds that traditional methods of kava preparation and which may potentially present additional risks (sale of such products is illegal in New Zealand). It is thus best to avoid such products not only because of the risk of adverse effects, but also because they usually fail to deliver the beautiful, and for many people beneficial, effects of pure, noble kava roots.
At the same time, while kava can be used safely by healthy adults, just like any other food or herbal product can, in very rare cases, cause adverse idiosyncratic, allergic reactions in some people. Likewise, it can negatively interact with certain medications and recreational drugs. This is why you should always consult a medical professional before consuming kava if you take any medications or suffer from any medical condition. You should also abstain from using alcohol or any other recreational drugs when you use kava.
And remember: If you have any doubts or concerns, please do consult your physician. We are not medical professionals. What we present here is the scientific literature we are familiar with and our own experiences related to kava consumption. If you do suffer from an illness, take any medications, require treatment, or have any other concerns, we strongly advise that you consult your GP whether you can safely use kava.
Moderate use of noble kava roots by healthy adults is not associated with any serious side effects. Stomach upsets/nausea is one of most common minor kava side effects. Some kavas (especially non-noble varieties, but also poorly peeled/processed kavas) are more likely than others to trigger nausea, but the consumption of excessive amounts of any type kava can lead to stomach upsets. We strongly advise against consumption of non-noble kavas and personally only drink noble, kavain-rich and very carefully processed kavas. It’s important to consume kava slowly and in moderation. If you have a sensitive stomach, we recommend consuming very well strained traditional kava (as micronised kava is a bit more likely to feel harsh on the stomach) and using real ginger root, or caffeine-free tea (peppermint) infused with ginger as chasers when drinking kava.
Kava is a diuretic, so unless you stay hydrated throughout your kava session and before you go to bed, you might experience minor dehydration and some related headache, especially if you consume excessive quantities of kava.
In some cases, prolonged use of large quantities of kava may cause a temporary and fully reversible skin condition called “kava dermopathy” (or “kani kani”). It is kava side effect that is characterised by dry, scaly and itchy skin. Some users have found that straining most or all of the sediment out of the prepared kava can be helpful in preventing it. The dermopathy may actually continue to spread after kava use is discontinued, but should begin to recede and disappear within 2-3 weeks (most recover sooner).
A very small number of users can experience a rare (and mostly minor) allergic reaction to kava, usually characterised by red and/or itchy skin. It might be necessary to discontinue kava use if you experience such symptoms. In the unlikely event that these symptoms persist or if you experience a more serious allergic reaction to kava, you should get in touch with a medical professional.
Unlike alcohol, nicotine or many of the prescription drugs (not to mention some of the illegal substances), kava is not physically addictive. As explained by Dr Lebot: “By pharmacological standards, kava is not classified as a drug, as its consumption never leads to addiction or dependency”. In fact, kava can be characterized by the so-called “reverse tolerance”, where new users require far greater amounts of the plant to feel any effects than those who drink it regularly. At the same time, we acknowledge that any substance taken for recreational or medicinal purposes has a habit-forming potential.
Kava is certainly an acquired taste. Kava scientists and consumers observe that it “has a strong, but not unpleasant smell. Its taste, which can be acrid and astringent, has been characterised as earthy (or ‘like dirt’ by less friendly drinkers)” or bitter. Heavier kava varieties tend to have a more unpleasant taste than the heady, kavain-rich ones. While it is hard to find a pleasant-tasting kava (and few people drink it for its taste), different cultivars have different and unique flavours. Certain kava cultivars (most notably those originating from parts of Tonga and Hawaii) are famous for their relatively mild taste. Others, especially those from parts of Vanuatu are known for their strong, earthy and bitter flavour. Kava flavour can also be affected by the quality of its processing, the more carefully cleaned and peeled the roots are the milder the taste. Another factor that affects the flavour is the ratio of lateral roots (the strongest part of the plant) to stump.
Many people like to use fresh fruits or real, non-alcoholic, ginger beer as chasers. Others like mixing micronised or instant kavas with their favourite fruit juices in order to mask the strong kava flavour.
Garry Stoner, the founder of True Kava gives the best summary of the key difference between kava and alcohol:
Kava doesn’t make you someone you’re not, it helps you be who you are. The effects of kava are not harsh like those of prescription drugs or alcohol. These substances usually have a profound and pronounced effect that is impossible to ignore. Kava is more subtle, and works in harmony with the body and mind. This is one of the qualities that makes kava so highly praised by its native consumers, whose subsistence requires an active lifestyle and full mental awareness.
In general, unlike alcohol, kava promotes peace, cooperation and tranquility. It does not diminish your mental clarity or awareness and if anything can help you to concentrate or overcome mental confusion caused by anxiety or stress. When taken in very large quantities, kava can negatively affect your coordination skills and can make you very sleepy. Unlike alcohol, it won’t make you aggressive or irresponsible for your own actions. Finally, noble kava roots won’t give you a hangover and there are very few known kava side effects.
Kava works best when it is consumed on an empty stomach, so it is a good idea not to eat or drink anything (other than water) for at least 4 hours before drinking kava. Kava is a diuretic, so it’s important to drink plenty of water in between or after kava shells. Kava sessions can be followed by a light meal. For many people a warm meal after kava potentiates the effects of the beverage.
We strongly advise against mixing alcohol and kava. Generally, it is best to abstain from drinking any alcoholic beverages for at least 24 hours before and after drinking kava.
A number of studies suggests that while kava is a powerful relaxant, at small (medicinal) doses it may actually enhance cognitive performance. In other words, despite its relaxing effects, it does not seem to necessarily impair mental functioning, at least when consumed in amounts covered by the above studies. It has also been found that, when taken in moderation (medicinal dose), kava does not impair driving ability. A recent study conducted at the Waikato University found that kava consumption (moderate amounts taken over the course of a session lasting 6 hours) had little effect on reaction time, perception and attention.
At the same time, it has been suggested that consumption of higher amounts of kava may reduce motor skills and therefore “caution is advised when driving or operating heavy machinery as psychomotor function can be significantly impaired when kava is consumed at higher doses”.
Kava is an important ingredient in pharmacopoeia of many Pacific Islands societies. Traditionally, it’s been used to treat a number of health problems including headaches, menstrual discomfort, infections, gastro-intestinal upset, skin disorders, stress, irritability and insomnia. As noted by Dr Lebot, modern research indicates that the chemical properties of kava’s active ingredients “may explain much of its usefulness in traditional medicine, although not all of its [traditional] applications can be accounted for scientifically”.
Another study conducted in 2005 found that kava may have “sleep quality-enhancement effects”, which is line with the experiences of many kava users who enjoy drinking kava before going to bed.
A 2000 study investigated the potential correlation between observed low cancer rates and high kava consumption. More recent research has looked at the potential effects of kava on preventing such types of cancer as: colon cancer, bladder cancer or cigarette smoke-induced lung cancer. While the preliminary results of these studies may appear promising, much more research needs to be done to determine if kava could indeed be effective or useful in preventing or treating different forms of cancer or any other serious disease.
Even though kava has been an important component of the traditional Pacific Islands medicine, most people consume it today as a traditional, relaxing and refreshing beverage and not a remedy for any health problems. This is also how we see, consume and promote kava. If you do require any health advice or have any health concerns, you should consult your qualified medical professional.
According to a report produced by the Food Standards Australia New Zealand: “Use of kava during pregnancy or lactation has been cautioned since kavalactones may be present at concentrations, which would likely have an effect on the foetus or infant (Brinker, 1998).”
As always, if you have any health concerns we strongly advise consulting your qualified medical professional to discuss the kava side effects.
FAQ are courtesy of The Kava Society.