In Chapter 1 of The Witcher 2, I encountered two people dressed in merchant clothing who asked me to test a potion for them, with promises of great rewards to come in a year or two at Vizima. They were whispering cautiously between themselves and one of them shouted that the gods have no love for my kind as I approached. In spite of this, I decided to be a trusting person and took the substance. According to my inventory, it's a Critical Effects mutagen.
While I know how to use mutagens, I'm cautious to apply this one without understanding the consequences. Is this just a convenient scenario used by the game as an introduction to mutagens or will it have consequences on my character during later events?