What are essential oils?

What are essential oils?

Essential oils are volatile, aromatic substances extracted from aromatic plants or fragrance-secreting animals. Typically, they are obtained from various parts of a plant—such as flowers, leaves, roots, seeds, fruits, bark, resin, or heartwood—using methods like steam distillation, cold pressing, enfleurage, or solvent extraction. Essential oils are categorized into diluted forms (blended oils) and undiluted forms (single-origin or "neat" oils, such as clove oil). Because they are highly volatile and evaporate rAPIdly upon exposure to air, they must be stored in airtight, dark-colored bottles.

Not all plants produce essential oils; only those containing secretory structures—such as glands or sacs—are capable of doing so. These structures are distributed differently across various plants, appearing on petals, leaves, roots, stems, or trunks. The substances extracted from these structures are what we call "plant essential oils." Essential oils are composed of a wide variety of constituents. They are lipophilic, meaning they dissolve easily in oils and fats; furthermore, their relatively short molecular chains allow them to penetrate the skin readily and enter the body via the abundant capillaries located beneath the subcutaneous fat. Composed of tiny molecules, these highly volatile substances can be absorbed into the body through the nasal mucosa, transmitting signals directly to the brain; there, they interact with the limbic system to regulate emotions and physiological functions. Consequently, in aromatherapy, essential oils serve to enhance both physical and psychological well-being. Each essential oil possesses a specific chemical structure that determines its aroma, color, viscosity, and mode of interaction with bodily systems, thereby endowing it with unique functional properties.