GlaxoSmithKline (GSK) issued a voluntary recall for all packages of its over-the-counter weight-loss drug Alli in the U.S. and Puerto Rico on Thursday as it continues to probe a number of packages that were tampered with.

Some of the packages are believed to contain pills and capsules of various sizes and colors that are not authentic to Alli, which comes as a turquoise blue capsule with a dark blue ban and the text “60 Orlistat”.

Other packages have their seal snapped open, are missing labels and have mismatched expiration dates. So far, packages in seven states have been affected: Alabama, Florida, Louisiana, Mississippi, New York, North Carolina and Texas.

GSK officially launched an investigation on Wednesday after receiving a number of consumer complaints. It is working with the U.S. Food and Drug Administration and is encouraging consumers to cooperate in the probe, alerting the company if they inadvertently purchase any suspicious bottles.

“Safety is our first priority and we are asking retailers and pharmacies to remove all Alli from their shelves immediately,” said Colin Mackenzie, GSK’s President Consumer Healthcare North America. “We are committed to finding out what happened and to doing everything possible to prevent future issues.”

GSK manufactures Alli in South Carolina, however, the drug giant has manufacturing facilities in both the U.S. and Puerto Rico and it’s unclear at what point in the manufacturing and supply process the authentic product was swapped out.

The British pharmaceutical giant has been selling Alli in the U.S. since 2007. Clinical trials have shown that Alli, when used in combination with a reduced calorie, lower-fat diet, can help people lose 50% more weight than by dieting alone.

Shares of GSK were up 0.43% to $53.82 in early trade.   

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