Its illegal in most of Europe because it has been proven to cause liver failure. However, the studies that concluded this were done on the plant. The root, which is what gives you the kava kava affect (the plant is sometimes added to make more use of the otherwise useless plant) will not hurt your liver. If you buy some, make sure it is only the root, or root extract.
It tastes like crap. But you can mix it with juice or add sugar to take the edge off.
It gives you a numbing feeling that really relaxes your muscles. The only way to see if it helps is to try it!
i tried it and it was amazing, made me feel stoned, dizzy, a little nauseated, but killed alot of my social and other anxiety. however i found it hard to concentrate or remember anything...didnt work to well in math. i used the WHOLE HEALTH brand
Even putting the modern extracts' issues aside, kava could be inherently toxic when used heavily. The descriptions of heavy kava users aren't something any sane person would aspire to. Perhaps green tea or N-acetyl-cysteine could protect the liver when using kava, but that's pure speculation (and liver toxicity isn't the only reported negative effect).
The jury's still out on kava, but I think non-regular use with the traditional preparation is likely to be perfectly safe if you avoid alcohol and are aware that it can interact with meds, supplements & drugs.
If you use the root, there should not be any risk of liver damage. The problem was with extracts. Pacific Islanders have been using lots of Kava for many many years and have had no history of liver disease/damage. Check out that thread for more information.