How does aromatherapy work?

Aromatherapy has effects on the body thanks to multiple methods of delivery. First, in the back of the nasal cavity, olfactory (smell) nerves, which carry over a thousand receptors, detect individual components of the volatile oil;^[1] the olfactory system is connected directly to the limbic system^[2] and to the hypothalamus,^[3] which is involved in control of the autonomic nervous system and is part of the hypothalamic-pituitary-adrenal (HPA) axis, the body’s stress management system. Second, in the lungs, volatile oil molecules can diffuse directly into the body in the capillary blood vessels of the alveoli.^[1] Finally, when volatile essential oils are applied topically, they can diffuse through the skin into subcutaneous tissue, and from there into the blood.^[1]