You may have seen pheromones advertised to calm anxious cats. Feline facial pheromone is precisely what your cat releases from the scent glands on his face. Products like Feliway are synthetic pheromones designed to be used to calm cats. Pairing the synthetic pheromone with a familiar item, such as a blanket, may help to keep your cat relaxed during stressful events such as a trip to the veterinarian.