Is kava legal in the United States?

Yes. Kava is legal to buy, sell and consume in the United States. It is not a controlled substance, it is not scheduled federally, and it is regulated as a dietary supplement.

What "regulated as a dietary supplement" means. Kava is sold under the framework the US applies to botanical supplements. Manufacturers are responsible for the safety and labelling of what they sell, and products are not pre-approved before going to market the way medicines are. In practice this puts the burden on the brand to demonstrate quality — which is why per-batch testing and published certificates of analysis matter more in this category than in most.

State and local position. There is no state-level ban on kava in the US. Kava bars operate openly across the country, most visibly in Florida, and kava drinks are sold in retail and online nationwide.

Internationally it varies. Several countries have restricted or regulated kava differently over the years, and some have since reversed those positions. If you are travelling with kava or ordering into another country, check that country's current rules rather than assuming the US position applies — this is the most common way people run into a problem.

Not a controlled substance means what it says. Kava is not scheduled, there is no possession limit, and buying it does not require anything special.

It is still a psychoactive botanical, and legality is a separate question from whether it is appropriate for you personally. See the entries on driving and on mixing with alcohol.