Essential oils chemically are liquid multicomponent mixtures. They are usually obtained by steam distillation or by extracting specific plant materials. The mixtures that are created differ in the content and properties of the components that make up a given essential oil.

The activity of the oil is determined by the concentration of compounds present in the mixture. They are most commonly used in three ways: by topical application on the skin, inhalation or as part of aromatherapy. One such oil is NOW Foods Essential Oil, which consists of lavender oil, ylang ylang oil, bergamot oil, orange oil, patchouli oil and cedarwood oil.