Kava Kava, known for its mood enhancing capacity, is coming under increasing scrutiny after studies have shown it to cause liver toxicity, even death. There are many forms of Kava Kava and it can be ingested in pill form or liquid tea. Its popularity has given rise to various Kava Kava bars popping up. However, GNC ordered the dietary supplement to be removed from its stores as long ago as December 2002.