Basil essential oil is used topically and massaged into the skin. It enhances the luster of dull-looking skin and hair. As a result, it is extensively used in many skin care supplements that claim to improve the tone of your skin. Basil essential oil is also used as a digestive tonic. Since basil oil has carminative properties, it is used for treating indigestion, constipation, stomach cramps. It provides immediate relief from the gas in your stomach and intestines.