Federal agencies including the Department of Justice will announce on Tuesday criminal and civil actions related to unlawful advertising and sale of dietary supplements.
Shares of dietary supplement makers GNC Holdings Inc were down 24 percent in afternoon trading, while those of Vitamin Shoppe fell nearly 8 percent and Herbalife Ltd 2.5 percent.
Herbalife spokesman Alan Hoffman said in an email the investigation had nothing to do with the company.
Representatives of GNC and Vitamin Shoppe were not immediately available for comment.
The DoJ said it would hold a news conference at 3:30 p.m. ET to announce the results of its investigation.
The DoJ said the news conference would be attended by representatives of the U.S. Food and Drug Administration, the U.S. Postal Inspection Service, the Federal Trade Commission, the Department of Defense and the U.S. Anti-Doping Agency.
GNC Holdings came under scrutiny from the office of New York Attorney General Eric Schneiderman earlier this year related to certain ingredients used in its herbal supplements.
GNC said in March it had restored certain herbal supplements to its stores in New York after reaching an agreement with Schneiderman's office.
(Reporting by Siddharth Cavale in Bengaluru; Editing by Saumyadeb Chakrabarty) Photo credit: Bradley Stemke/Flickr