Abstract: A method for authenticating the contents of containers. The method utilizes a security label including a removable piggyback label having an authentication feature. The method generally includes: obtaining a bulk container with contents stored therein, the container labeled with the security label and the authentication feature indicative of the contents; transferring at least a portion of the contents from the bulk container to a consumer container; and transferring the piggyback label having the authentication feature to the consumer container to verify the authenticity of the transferred contents. This method is useful when transferring pharmaceutical products from a bulk container to individual consumer containers because consumers can be confident that the pharmaceuticals stored by their containers are authentic.