The term Essential Oil is misleading. Essential Oils are not oily or greasy, they evaporate readily, leaving no residue. As they evaporate, the aromatic molecules permeate the air. When we inhale the aroma those molecules travel into the nose and to olfactory receptors where our sense of smell originates. These receptors then transmit information about the odor to the limbic system in the brain. The essential oil molecules don't stop in the brain, they travel to the lungs and then to the bloodstream, where they improve on health by acting on individual cells.
Also, readily absorbed by the skin, they should be diluted by a carrier oil, such as almond oil to prevent irritation to the skin. Once the Essential Oils penetrate the skin, they can stimulate circulation and encourage cell regeneration.
Whether inhaled or absorbed through the skin, Essential Oils can fight bacteria, fungi, viruses, and other microbes inside the body and can stimulate the immune system to help renew health.