Treatment Experience
I tried kava kava in almost all forms and almost all kinds of preparation.

84% kavaloctone paste.
pulverised kava root powder.
kava kava pills.
kavaloctone full spectrum paste.
kava tincture.
kava gooey liquid.

and I got no effect from none of the above mentioned products. I am never gonna buy kava again because I think I am immune to the stuff or something.
But I guess it would be worth a try for everyone with anxiety, because the effects from the herb sounds very nice and anxiolytic.

Treatment Experience

Kava helps a lot with anxiety and supports a more positive mood. I also suffer from slight depression although St. John's Wort and fish oil have helped that immensely.

Kava varies quite a bit in different brands. Kavalactones are the main things that give you the calming feeling. You need around 70 mg - 200 mg of Kavalactones to feel a reduction in anxiety.

I would highly recommend getting high grade kava root powder from a reliable online store (just search google). This works much better than pills (which are much weaker). You need to get kava root powder that is at least 4-5 years old and uses strictly lateral roots. You mix it with water and it tastes like crap (but if you can stomach it the effects are probably worth it). I need to try some other recipes and see if I can get it to taste better.

Kava root powder does not cause liver damage. The reason Germany and many other European countries banned it was due to several people having it their system along with alcohol and other drugs. The deaths were attributed to Kava unfairly and independent studies looking into this have said it cannot be blamed on Kava. Plus the Kava they were using was said to be Kava extract with parts of Kava besides the root which can cause liver damage.

Kava is very safe and a much better alternative to alcohol and other drugs that can be damaging to the body.

I have been researching Kava a ton since my mom first told me about it. http://www.erowid.org/plants/kava is an excellent site for experiences and more info about Kava. I have learned a ton from other people's experiences on there.

In the past, I have used weak (2% Kavalactone pills so 12.5 mg of Kavalactones) and I took close to 20 and I started to feel effects but not very strong.

I have used kava root powder maybe 10 times or so. They say take closer to 2-3 Tbsp. I have taken this amount and felt a significant relief of anxiety (but doesn't compare to Xanax). I never have finished my bag of Kava root because I can't stomach the taste anymore.

You should definitely be able to feel the effects of Kava. If you think you are feeling a placebo effect or are not sure, you are not taking enough. You will feel the effects if you dose it correctly.

I have heard tolerance does not build up that much. But there is a reverse tolerance for some people. Meaning that you need to drink Kava a few times before you will feel the full effects.

Kava works great for social anxiety and I am so glad I finally tried the root powder. Otherwise you need to take a lot of pills (depending on their amount of Kavalactones) to get effects. And even then I still think powder is the way to go. I highly suggest you give it a try

Check this forum thread for more information about Kava http://www.socialanxietysupport.com/forum/f11/kava-kava-45974/