Hi,
I double post this message because I think it is so important to be aware that Kava is not a non toxic nootropic.
Kava (Piper methysticum) can be very toxic to the liver - and there is
no safe dose of kava! You might want to stay away from it!
Below you'll find an extract from wiki:
"Liver damage incidents and regulation
In 2001 concerns were raised about the safety of commercial kava products. [13] There have been allegations of severe liver toxicity, including liver failure in some people who had used dietary supplements containing kava extract (but not in anyone who had drunk kava the traditional way). Out of the 50 people worldwide taking kava pills and extracts that have had some type of problem, almost all of them had been mixing them with alcohol and pills that could have effects on the liver.[13] The fact that different kava strains have slightly different chemical composition made testing for toxicity difficult as well.
The possibility of liver damage consequently prompted action of many regulatory agencies in European countries where the legal precautionary principle so mandated. In the UK, the Medicines for Human Use (Kava-kava) (Prohibition) Order 2002 prohibits the sale, supply or import of most derivative medicinal products. Kava is banned in Switzerland, France and The Netherlands[14]. The health agency of Canada issued a stop-sale order for kava in 2002. But legislation in 2004 made the legal status of kava uncertain. The United States CDC has released a report[15] expressing reservations about the use of kava and its possibly adverse side effects (specifically severe liver toxicity), as has the Food and Drug Administration (FDA).[16] The Australian Therapeutic Goods Administration has recommended that no more than 250 mg of kavalactones be taken in a 24 hour period.[17] According to the Medicines Control Agency in the U.K., there is no safe dose of kava, as there is no way to predict which individuals would have adverse reactions.[18]"
source:
http://en.wikipedia.org/wiki/KavaAnd several extracts from Pubmed:
"Hepatocellular toxicity of kava leaf and root extracts.
Lüde S, Török M, Dieterle S, Jäggi R, Büter KB, Krähenbühl S.
Division of Clinical Pharmacology & Toxicology, Department of Research, University Hospital, CH-4031 Basel, Switzerland.
Kava extracts are used widely for different purposes and were thought to be safe. Recently, several cases of hepatotoxicity have been published. To explore possible mechanisms of kava hepatotoxicity, we prepared and analyzed three different kava extracts (a methanolic and an acetonic root and a methanolic leaf extract), and investigated their toxicity on HepG2 cells and isolated rat liver mitochondria. All three extracts showed cytotoxicity starting at a concentration of 50 microg/ml (lactate dehydrogenase leakage) or 1 microg/ml (MTT test). The mitochondrial membrane potential was decreased (root extracts starting at 50 microg/ml) and the respiratory chain inhibited and uncoupled (root extracts) or only uncoupled (leaf extract) at 150 microg/ml, and mitochondrial beta-oxidation was inhibited by all extracts starting at 100 microg/ml. The ratio oxidized to reduced glutathione was increased in HepG2 cells, whereas the cellular ATP content was maintained. Induction of apoptosis was demonstrated by all extracts at a concentration of 150 microg/ml. These results indicate that the kava extracts are toxic to mitochondria, leading to inhibition of the respiratory chain, increased ROS production, a decrease in the mitochondrial membrane potential and eventually to apoptosis of exposed cells. In predisposed patients, mitochondrial toxicity of kava extract may explain hepatic adverse reactions of this drug.
PMID: 18055189 [PubMed - indexed for MEDLINE]"
"Toxicity of kava kava.
Fu PP, Xia Q, Guo L, Yu H, Chan PC.
National Center for Toxicological Research, Jefferson, Arkansas 72079, USA. peter.fu@fda.hhs.gov
Kava is a traditional beverage of various Pacific Basin countries. Kava has been introduced into the mainstream U.S. market principally as an anti-anxiety preparation. The effects of the long-term consumption of kava have not been documented adequately. Preliminary studies suggest possible serious organ system effects. The potential carcinogenicity of kava and its principal constituents are unknown. As such, kava extract was nominated for the chronic tumorigenicity bioassay conducted by the National Toxicology Program (NTP). At present toxicological evaluation of kava extract is being conducted by the NTP. The present review focuses on the recent findings on kava toxicity and the mechanisms by which kava induces hepatotoxicity."
Cheers
Alex
Very thorough poll. Though mygenus' comments are true, this will still provide a starting point for newbs pointing toward which noots have the highest response rate. We don't have very good tools to asses "individual pharmacogenetic and genoneurotransmission profile" in mygenus' words, so this is not too important yet. I can imagine in a few hundred years we may have the technology for this, and our approach of trial and error will seem rudimentary. We are in the stone age of nootropics.
BTW kava owns