Tests showed it contained a controlled substance, sibutramine, which could interact in a harmful way with other medications.
HOW TO IDENTIFY THE FAKE PRODUCT:
-The LOT code information is missing from the top of the box
-The expiration date includes month, day and year (example: 06162010); The authentic alli expiration date includes only the month and year (example: 05/12)
-The seal on the bottle should read "SEALED FOR YOUR PROTECTION" in white ink on the GSK Alli bottle; This statement is not present on the fake product
-The capsule size is slightly larger in the counterfeit and the content inside of the capsule is different - the counterfeit content is powdery and the genuine product is more of a pellet shape.
Consumers who suspect they have purchased counterfeit Alli are urged to contact the FDA.
And visit the official Alli website for more information