Mister Fear employs a compound based on the flight scent pheromone—chemicals produced by most animals, used to communicate a variety of simple messages over distances. This flight-scent pheromone stimulates fear reactions in herd animals. The drug is tailored for human beings, whose reactions to pheromones are not completely understood. It induces severe anxiety, fear, and panic, and sometimes nightmarish hallucinations in his victims, rendering them incapable of fighting or resisting his will. The drug is most commonly used in the form of gas pellets shot from a gun. The pellets rupture on contact, releasing the flight scent, which is inhaled by the victim. The dosage contained in one pellet is enough to incapacitate a normal adult male for about 15 minutes, or an exceptionally fit male, such as Daredevil, for about five minutes. The side effects of anxiety, edginess, and mild nausea can persist for several days.