Dried blackbane leaves are poisonous. Ingesting them causes paralysis, which in turn keeps the victim from being able to breathe. Victims of blackbane poisoning have visibly darkened skin afterwards. Blackbane is difficult to make to its full potency. For that, one must first let the leaves dry and then make it into a gum. The dried leaves are said to become more potent the longer they are aged. Ingesting the blackbane paste, however, does not kill as quickly as injecting the essence straight into the blood.