Kava or kava-kava(Piper methysticum)is a plant used for the production of a ritual drink with tranquilizing properties.The kavalactones are the main compounds of the kava drinks(see Table 1 for names and structures of the main kavalactones).There are many clinical trials on the use of kava product for anti-anxiety,and a systematic review supports the use of kava for the treatment of generalized anxiety(Sarris et al.,2009).Adverse effects on the liver have been reported,and kava is regulated in a number of countries(Teschke,2010).Studies of kava extracts Kava or kava-kava (Piper methysticum) is a plant used for the production of a ritual drink with tranquilizing properties. Kavalactones are the main compounds of the kava drinks (see Table 1 for names and structures of the main kavalactones). There are many clinical trials on the use of kava product for anti-anxiety, and a systematic review of the use of kava for the treatment of generalized anxiety (Sarris et al., 2009). Adverse effects on the liver have been reported, and kava is regulated in a number of countries (Teschke, 2010). Books of kava extracts