It is makrooh tahreemi (prohibited and sinful) to drink kava. Research by the Australian government shows that kava consumption has short-term benefits but many long-term harms, including negative health impacts and causing apathy, leading to neglect of responsibilities. Due to these negative effects, the Australian government has restricted its buying and selling. Additionally, Islamic teachings prohibit consuming anything that intoxicates or causes a lapse in the mind. Therefore, drinking kava is considered impermissible.

Sources:

1. Darul Ifta Australia
2. IslamQA

And Allah knows best.