It was also fatal to Time Lords. (AUDIO: The Ghosts of Gralstead) Though there was no naturally occurring cure, an anti-toxin was created by the Fourth Doctor using a bioanalyser in combination with a medikit. He successfully used this cure on Leela, against whom Calib had used a thorn. (TV: The Face of Evil) Leela threatened a death-dealer named Jason with a janis thorn. (AUDIO: Death-Dealer) Leela still kept her janis thorns when she was living on Gallifrey. (PROSE: Lungbarrow)