time, it was observed that: on the other hand, there is strong evidence that high levels of consumption of kava beverage can result in scaly skin rash, weight loss, nausea, loss of appetite and indigestion. these adverse health effects, while significant, are considered to be reversible upon cessation of kava use. other possible effects include sore red eyes, laziness, loss of sex drive and general poor health. no effect on cognition, which might be associated with the pharmacological activity of kava, has been identified. no information is available on the potential for kava beverage consumption to impact on the incidence of chronic disease. moderate to high kava beverage consumption also produces a reversible increase in the liver enzyme gamma glutamyltransferase (ggt), which may be an early indicator of cholestasis. clinical surveys in aboriginal communities in northern australia with a history of heavy kava use have not revealed any evidence of long-term liver damage associated with consumption of kava beverage. a human health risk assessment conducted by the australian and new zealand governments concluded that: 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. (...) the available data (...) does not suggest any specific health problems associated with moderate use of kava beverage. a 2013 overview of 50 systematic reviews listed the pyper methysticum among the only four of the 50 monitored herbal medicines which showed serious adverse effects for the human health. effects on the liver according to a 2010 discussion paper prepared for the codex alimentarius commission: "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 hepatotoxicity 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." in 2001, concerns were raised about the safety of kava, which led to restrictions and regulations in several countries, as well as reports by the united states cdc and fda. in response to media reports from europe, in 2002 the fda issued a (now archived) consumer advisory stating that, "kava-containing dietary supplements may be associated with severe liver injury." likewise, livertox of the national library of medicine/national institutes of health noted that: "the frequency of adverse reactions to kava, particularly liver injury, is not known... between 50 and 100 cases of clinically apparent liver injury have been published or discussed in the literature. advocates for the herb have strongly rejected these numbers, disputing both their accuracy and the causality assessment process. still, there seems to be convincing evidence in some cases of severe hepatitis ending in fulminant hepatic failure, requiring liver transplantation, and even leading to death." most of the concerns were related to a small number of reports indicating potential cases of hepatotoxicity caused by consumption of various commercial products derived from kava. a number of scientists and medical practitioners criticized the poor quality of the reports by pointing out that most of the reported rare cases of hepatotoxicity involved patients with a history of alcohol or prescription drug abuse or concomitant use of medicines known as potentially hepatotoxic. likewise, the australian studies from the late 1990s suggesting an association between health problems and heavy kava use, that contributed toward the rise of concerns about kava were found to be focused on populations with very heavy concomitant consumption of alcohol and overall poor health. more rigorous clinical research has found no evidence of any significant negative health issues (including any irreversible liver damage) that could be linked to kava. in light of this information and subsequent research on 10 june 2014, the german administrative court overturned the 2002 ban reinstating the regulatory requirements of 2001. the court stated that risk from kava exposure had not been clearly demonstrated, nor does it appear unusually high, an opinion presumably driven by the very small number of cases of reported toxicity (n ~ 3) with even a certain degree of causality linked to kava in a global kava-consuming community that may number in the millions of doses consumed daily. according to one comprehensive review: "despite the link to kava and liver toxicity demonstrated in vivo and in vitro, in the history of western kava use, toxicity is still considered relatively rare. 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." according to an in-depth human health risk assessment commissioned by the new zealand and australian governments, while consumption of kava may result in such minor and reversible side effects as kava dermopathy (see below), "there is no evidence that occasional use of kava beverage is associated with any long-term adverse effects, including effects on the liver." aside from "the small number of cases of kava hepatotoxicity due to an idiosyncratic reaction of the metabolic type", "liver injury by kava is basically a preventable disease". in order to minimize or eliminate the risk of liver injury, only high-quality plant material should be used in the preparation of kava supplements or kava beverages. in particular, the use of the so-called "two-day" (known also as "tudei", "isa", "palisi") and wild (piper wichmanii) cultivars traditionally not consumed, should be avoided. the use of these cultivars in the manufacturing of kava-based pharmaceutical products is undesirable due to their very different phytochemistry and relatively high concentrations of potentially harmful compounds (flavokavains). while other ("noble") cultivars also contain these compounds, toxicity seems to be triggered only at relatively high concentrations, too high to be of relevance with the use of noble kava or its corresponding extract preparations". such cultivars mainly grow in vanuatu, which outlawed their exports in 2004. other adverse reactions adverse reactions may result from the poor quality of kava raw material used in the manufacturing of various kava products. in addition to the potential for hepatotoxicity, adverse reactions from chronic use may include visual impairment, rashes or dermatitis, seizures, weight loss, and malnutrition, but there is only limited high-quality research on these possible effects. on the basis of research findings and long history of safe use across the south pacific, experts recommend using water-based extractions of high-quality peeled rhizome and roots of the noble kava cultivars to minimize the potential of adverse reactions to chronic use. potential interactions several adverse interactions with drugs have been documented, both prescription and nonprescription – including, but not limited to, anticonvulsants, alcohol, anxiolytics (cns depressants such as benzodiazepines), antipsychotics, levodopa, diuretics, and drugs metabolized by cyp450 in the liver. a few notable potential drug interactions are, but are not limited to: alcohol: it has been reported that combined use of alcohol and kava extract can have additive sedative effects. regarding cognitive function, kava has been shown to have additive cognitive impairments while taken with alcohol when compared to taking placebo and alcohol alone. anxiolytics (cns depressants such as benzodiazepines and barbiturates): kava may have potential additive cns depressant effects (such as sedation and anxiolytic effects) with benzodiazepines and barbiturates. dopamine agonist – levodopa: one of levodopa's chronic side effects that parkinson's patients experience is the "on-off phenomenon" of motor fluctuations where there will be periods of oscillations between "on" where the patient experiences symptomatic relief and "off" where the therapeutic effect wears off early. when taking levodopa and kava together, it has been shown that there is an increased frequency of this "on-off phenomenon". kava dermopathy long term and heavy kava consumption is associated with a reversible skin condition known as "kava dermopathy" or kanikani (in the fijian language), characterised by dry and scaly skin covering the palms of the hands, soles of the feet, and back. the first symptom to appear usually is dry, peeling skin; some pacific islanders deliberately consume large quantities of kava for several weeks in order to get the peeling effect, resulting in a layer of new skin. these effects appeared at consumption levels between 31 grams (1.1 oz) to 440 grams (0.97 lb) a week of kava powder. despite numerous studies, the mechanism that causes kava dermopathy is poorly understood "but may relate to interference with cholesterol metabolism". the condition is easily treatable with abstinence or lowering of kava intake as the skin appears to be returning to its normal state within a couple of weeks of reduced or no kava use. kava dermopathy should not be confused with rare instances of allergic reactions to kava that are usually characterised by itchy rash or puffy face. research kava is under preliminary research for its potential psychoactive – primarily anxiolytic – sleep-inducing, and sleep-enhancing properties. preliminary randomized controlled trials in anxiety disorders indicate a higher rate of improvement in anxiety symptoms after kava treatment, relative to placebo. traditional medicine a traditional fijian yaqona bundle of roots over centuries, kava has been used in the traditional medicine of the south pacific islands for central nervous system and peripheral effects. as noted in one literature review: "peripherally, kava is indicated in traditional pacific medicine for urogenital conditions (gonorrhea infections, chronic cystitis, difficulty urinating), reproductive and women's health (...), gastrointestinal upsets, respiratory ailments (asthma, coughs, and tuberculosis), skin diseases and topical wounds, and as an analgesic, with significant subtlety and nuance attending the precise strain, plant component (leaf, stem, root) and preparative method to be used". regulation kava remains legal in most countries. regulations often treat it as a food or dietary supplement. australia in australia, the supply of kava is regulated through the national code of kava management. travellers to australia are allowed to bring up to 4 kg of kava in their baggage, provided they are at least 18 years old, and the kava is in root or dried form. commercial import of larger quantities is allowed, under licence for medical or scientific purposes. these restrictions were introduced in 2007 after concern about abuse of kava in indigenous communities. initially, the import limit was 2 kg per person; it was raised to 4 kg in december 2019, and a pilot program allowing for commercial importation was implemented on 1 december 2021. the australian therapeutic goods administration has recommended no more than 250 mg of kavalactones be taken in a 24‑hour period. kava possession is limited to 2 kg per adult in the northern territory. while it was banned in western australia previously in the 2000s, the western australian health department announced lifting of its ban in february 2017, bringing western australia "into line with other states" where it has always remained legal, albeit closely regulated. europe following the discussions on the safety of certain pharmaceutical products derived from kava and sold in germany, in 2002 the eu imposed a temporary ban on imports of kava-based pharmaceutical products. the sale of kava plant became regulated in switzerland, france, and in prepared form in the netherlands. some pacific island states who had been benefiting from the export of kava to the pharmaceutical companies have attempted to overturn the eu ban on kava-based pharmaceutical products by invoking international trade agreements at the wto: fiji, samoa, tonga and vanuatu argued that the ban was imposed with insufficient evidence. the pressure prompted germany to reconsider the evidence base for banning kava-based pharmaceutical products. on 10 june 2014, the german administrative court overturned the 2002 ban making selling kava as a medicine legal (personal possession of kava has never been illegal), albeit strictly regulated. in germany, kava-based pharmaceutical preparations are currently prescription drugs. furthermore, patient and professional information brochures have been redesigned to warn about potential side effects. these strict measures have been opposed by some of the leading kava scientists. in early 2016 a court case has been filed against the bundesinstitut für arzneimittel und medizinprodukte (bfarm/german federal institute