Nasal administration, popularly known as snorting, is a route of administration in which drugs are insufflated through the nose. It can be a form of either topical administration or systemic administration, as the drugs thus locally delivered can go on to have either purely local or systemic effects ibuprofen or Tylenol for headaches along with pains such as severe toothaches. Nasal sprays are locally acting drugs such as decongestants for cold and allergy treatment, whose systemic effects are usually minimal. Examples of systemically active drugs available as nasal sprays are migraine drugs, rescue medications for overdose and seizure emergencies, hormone treatments, nicotine nasal spray, and nasal vaccines such as live attenuated influenza vaccine.

The sense of smell, or olfaction, is the special sense through which smells are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste.