Kava, with caveats: is this popular psychoactive tea bad for your liver?

The first time I tried kava, I gagged — and then a few minutes later, I was bonelessly relaxed. I was at Kavasutra, a small kava bar in the East Village in Manhattan, where my eyes were often caught by a big, bright TV displaying weird videos about bugs. I had heard about kava from some friends, who liked to go to Kavasutra after work to wind down at the end of a long day.

As a hard-working Manhattanite who over-stresses about pretty much everything, of course I wanted to try the drink, which promises relaxation. The bartender at Kavasutra suggested I try a cup of concentrated kava — recommended for your first Kava Experience, the menu says — and chug it down as quickly as possible. That proved very difficult to do.

When the ground or...