Aromatherapy is the use of essential oils for therapeutic purposes. Aromatherapy has been practiced for thousands of years. When essential oils are inhaled, the scent molecules travel directly from the olfactory nerves to the brain, focusing on the amygdala, the brain's emotional center. The skin can also absorb essential oils. To help relax tight muscles during a rubdown, a massage therapist may add a drop or two of wintergreen oil to the oil. To create a soothing soak, a skincare company may add lavender to bath salts. The quality of essential oils available on the market varies greatly, ranging from pure essential oils to those diluted with less expensive ingredients. Because there is no regulation, the label may not even list everything in the bottle you're purchasing. As a result, essential oils should not be consumed.