Dow Jones -- The Food and Drug Administration on Monday warned consumers about a counterfeit version of GlaxoSmithKline PLC’s (GSK, GSK.LN) weight-loss drug Alli. Alli is sold over-the-counter in a variety of retail stores. The counterfeit version was purchased by consumers on the Internet, and GlaxoSmithKline started receiving complaints about the product last month. Glaxo said the product was purchased from online auction sites like eBay Inc. (EBAY).