I know of a several companies that made drinks, some were fizzy and some were not but the thing they all had in common and I think that this one is that way too, they are made with a standardized extract. I personally like to stay away from extracts of kava, I like the traditional way of using kava. For example, there was a study that was done recently and since I am not up on my cellular biology I can only tell you the gist of things.
The study took Human cells and put kava extract on it, and nothing happened, when they put the water extract, like they drink in Vanuatu, the cell came alive with activity, good activity so that tells us something about the real thing and the extracts. Aloha.
Chris