Quoting from:
http://www.ncahf.org/digest07/07-42.html

Liver toxicity reported among Herbalife users. More than
20 cases of liver toxicity have been reported among Herbalife
users in two countries. In Israel, a ministry of health
investigation of hospitalized patients identified 12 users
who developed acute liver injury. One succumbed to
complications following liver transplantation. The rest
recovered, but three who resumed taking the products had
their hepatitis recur. [Elanav E and others. Association
between consumption of Herbalife nutritional supplements
and acute hepatotoxicity. Journal of Hepatology 2007]
In Switzerland, ten more cases were located by sending
questionnaires to all Swiss public hospitals. The researchers
said that their investigation was hampered by the fact that
the involved products did not specify their ingredients on
their labels. Despite this, they concluded that causality
was certain in two cases, probable in seven, and possible
in one. [Schoepfer AM and others. Herbal does not mean
innocuous: Ten cases of severe hepatotoxicity associated with
dietary supplements from Herbalife products. Journal of
Hepatology 47:521-526, 2007] The full text of the Swiss
study is online.