PITTSBURGH -- Kava is a dietary supplement known to make people relax, but the Food and Drug Administration warned consumers it could do more.

The FDA notified health care professionals that there have been several cases of people whose livers have shut down after they used kava.

Several countries have removed kava from store shelves, but it is still legal in the U.S. In fact Channel 11 found kava in several local health food stores.

Kava is made from the root of a pepper plant found in the South Pacific. It’s often consumed in tea. You can also find the supplement in capsule form and tea bags in some health food stores marketed for treatment of anxiety, insomnia and stress.

The Medical Director of Gateway Rehab Dr. Neil Capretto told Channel 11 kava can be very dangerous. "When you start using higher amounts it can act like a drug called Ecstasy they can have hallucinations," said Capretto.

A few years ago, a 14-year-old girl had to undergo a liver transplant at Children’s Hospital in Pittsburgh after using kava. Its many forms are readily available on the Internet and Capretto said the problem is there's no quality control so you really don't know what you're getting.