I think FKB -a compound in kava, causes cancer cell apoptosis in some manner. From my experience personally, I can’t speak to any immune boosting effects. There are definitely minor short and mid term side effects, such as nausea, weight loss, dry or chapped skin, increased cholesterol (I thought only good cholesterol, but some older drinkers here seem concerned) and perhaps most problematic, dehydration. I have my doubts that long term kava use is beneficial for the body. Certainly not harmful like alcohol or other things,but I think it is best to use in cycle, maybe 1 month off one month on, or 3x per week if you were looking to get true health benefits without an equal health cost. That said, I use it daily. At the end of the day, too much of anything is not the best.