Lemon oil comes from the Citrus lemon tree, from the rind of the same lemon fruit that we eat. Lemon oil is commonly used in cosmetics for its supposed benefits for the skin. It is thought to improve all skin types but especially oily skin with its astringent qualities. Lemon is used for sore throats, coughs and bronchitis, colds and the flu, as well as digestive concerns like indigestion and gas.