Thieves oil is a blend of plant-based essential oils that is used for immune support, enhancing lung and sinus function and purifying the air, according to Natural Aromatherapy Benefits. The U.S. Food and Drug Administration hasn't evaluated the effectiveness of this oil as a supplemental health product, as of 2015.
Thieves oil is a blend of clove, cinnamon, eucalyptus, rosemary and lemon oil, according to Natural Aromatherapy Benefits. The exact proportions of the oils may vary by recipe. Diluted Thieves oil serves as a household deodorizer and cleaner and an antibiotic solution for acne and minor cuts. Other uses include diluting the oil in tea as a digestive aid and mixing a few drops with honey to freshen the breath.
Each of the oils in Thieves oil has a different set of benefits, according to WebMD. For example, clove oil is useful for the treatment of coughing, upset stomach and toothache and as a mosquito repellent. There is insufficient scientific research to support the effectiveness of clove oil for these uses.
Cinnamon bark oil, another ingredient of Thieves oil, is sometimes used to reduce gas and spasms, however, it hasn't been proven effective for these purposes, cautions WebMD. Manufacturers use cinnamon oil in products such as toothpaste, lotion and liniment.