I just had the following conversation with a GNC employee over the phone:
GNC E: Hello, this is __, how may I help you?
Me: Do you carry a pure Guarana seed extract containing caffeine and no additional ingredients?
GNC E: Well, Guarana equals caffeine, and we do carry Guarana
Me: Ok, thanks, what are the ingredients in what you have?
Him: Let's see: 250mg Guarana, with 90mg of caffeine. And it looks like we only have 1 left.
Me: Would you mind putting that on hold? I will be coming by tomorrow
Him: Hmm.. well, ok I have 3 so I can probably hold onto one for you