Where is the bottom of this pit?

In a continuing investigation that has prompted consumer warnings and recalls by some distributors, the F.D.A. has determined that dozens of weight-loss supplements, most of them imported from China, contain hidden and potentially harmful drugs. In the coming weeks, the agency plans to issue a longer list of brands to avoid that are spiked with drugs, an F.D.A. spokeswoman said.

[From F.D.A. Finds ‘Natural’ Diet Pills Spiked With Drugs - NYTimes.com]