Essential oils are complex mixtures of volatile organic compounds extracted from plants, primarily consisting of terpenes, terpenoids, phenols, and other aromatic molecules. They are used in food, cosmetics, and medicine for their flavor, fragrance, and therapeutic properties. Properties vary greatly depending on the source plant, such as lavender, peppermint, or citrus oils. They are typically lipophilic and evaporate readily at room temperature. No single chemical formula or set of properties applies to all essential oils.