"Yes, and if I were to feed it to a veela, sure, probably pretty toxic.  However, given the lycanthropic traits of man  and creature, rather than always being creature, the premise of valerian root still works.  Feed it to the man while he’s still man, in small doses, and it will work to help negate the effects of the creature without poisoning it."  She shrugged, as if this was common knowledge.  "Oh, and I spent a summer in the same safe house as a werewolf.  I’m well versed in the wolfsbane potion."