Azaperone, also known as Stresnil, is a sedative used mainly to calm swine before and during transport and ahead of slaughter. It is commonly given a few hours before slaughter; calmer animals are safer to handle and produce better-quality meat, since stress depletes muscle glycogen and causes defects such as pale, soft, exudative pork. However, high levels of active residues in edible tissues are a potential hazard to consumers if withdrawal times are ignored, so its veterinary use is tightly regulated with mandatory clearance periods. Residue monitoring programmes test pork to verify compliance and protect the food supply.