Is kava kava illegal in the U.S.?

As a cryptocurrency and finance practitioner, I'm often asked about the legality of various substances in the context of financial transactions. Recently, I've encountered a question regarding kava kava and its legal status in the United States. Could you please clarify, is kava kava considered illegal in the U.S.? Are there any specific laws or regulations that prohibit its use, sale, or possession? I'm aware that some substances may be regulated due to their potential health risks, so I'm curious to know if this applies to kava kava. Thank you for your clarification on this matter.