A drug is considered counterfeit if:

A drug is considered counterfeit when it possesses an unauthorized label, meaning that the labeling does not accurately represent the drug’s identity or source. This can include false information about the drug’s ingredients, strength, manufacturer, or user instructions. The presence of an unauthorized label suggests that the product may not have been produced in accordance with regulatory standards, rendering it potentially unsafe, ineffective, and illegal.

When assessing the other options, an authorized trademark does not necessarily indicate that a drug is counterfeit; it may very well belong to a legitimate product. Similarly, a drug produced by a different brand does not automatically imply that it is counterfeit, as different manufacturers may produce legitimate medications with proper regulations. Lastly, packaging that is correct does not confirm authenticity; counterfeit drugs can sometimes be packaged to look legitimate while still being mislabeled or improperly manufactured. Therefore, the defining characteristic of a counterfeit drug primarily revolves around unauthorized labeling.