Kava kava is an erotic friend of mine. Which may surprise those who think of this root from the South Seas as a sleep-inducing sedative. And which may dismay those who think of Piper methysticum as a standardized extract or capsule or pill capable of causing liver failure.
As for the latter, my reading, and my own experiences, led me to believe that my liver is quite safe if I restrict my kava kava consumption to water-based preparations. And, again from my own experiences, infusions of the fresh or dried root fermented in water are also far stronger in effect than capsules, pills, or extracts. I let my kava kava brew sit for 1-10 days before use. It seems to get stronger the longer it sits.
As to the former, I found kava kava ready to ease me into sleep, 'tis true, if I wished. I also found a cup or two of the brew ready to help me through a day of work or an evening of play (in bed). As always, the set (what you think is going to happen, or what you set your mind to have happen) and the setting (where you are physically and emotionally) have a lot to do with the effect you experience. Enjoy!