Essential oils are absorbed by the respiratory mucous membrane, but also stimulate the olfactory receptors above the nasal passages. Consequently, information is sent to the limbic system, a strategic area of the brain that governs the emotions and behaviour. The effect can therefore be physical and psychological.
Advantage: This route of administration is quick and easy, especially for the upper respiratory tract (rhinopharynx, sinuses, etc.). It also creates a pleasant, fragrant, beneficial atmosphere (for the respiratory system, against stress, at bedtime, etc.).