Is kava illegal?

Is it true that kava, a traditional Pacific Island plant often used for its relaxing effects, is illegal in certain parts of the world? I've heard rumors that its possession or use could lead to legal consequences in some jurisdictions. Could you clarify the legality of kava, highlighting any specific countries or regions where it might be restricted or prohibited? Additionally, are there any health concerns associated with its consumption that might also be of relevance to its legal status?