Thieves oil is most commonly used during illness through diffusing, steam inhalation, or diluted topical application to the chest and feet. The blend combines clove, lemon, cinnamon bark, eucalyptus, and rosemary essential oils in a roughly 40-30-15-10-5 ratio, and each method of use carries different benefits and risks worth understanding before you start.
Diffusing to Clear the Air
The most popular way to use thieves oil when you’re sick is in a diffuser. Add 4 to 6 drops to an ultrasonic or nebulizing diffuser and run it in intervals of 30 to 60 minutes on, then 30 to 60 minutes off. This disperses the oil into fine microdroplets that you breathe in passively. The eucalyptus and rosemary components contain compounds that can help open up your airways and make breathing feel easier when you’re congested.
Keep the room ventilated. Running a diffuser in a small, sealed room concentrates the oil in the air and can irritate your nose, throat, and eyes. If you notice a burning sensation in your nose or throat, or if you start coughing more, turn the diffuser off and open a window.
Steam Inhalation for Congestion
For more targeted relief from nasal and chest congestion, add 2 to 3 drops of thieves oil to a bowl of hot (not boiling) water. Drape a towel over your head, close your eyes, and lean over the bowl at a comfortable distance. Breathe in the steam through your nose for 5 to 10 minutes. The warm, moist air combined with the eucalyptus and rosemary can help loosen mucus and temporarily ease sinus pressure. Keep your face at least 12 inches from the water to avoid burns from steam or oil vapors.
Diluted Chest and Foot Rubs
You can apply thieves oil topically, but proper dilution is critical. Cinnamon bark oil is one of the most irritating essential oils for skin. The Tisserand Institute recommends cinnamon bark be diluted to just 0.1% for safe skin use, and undiluted application has caused second-degree chemical burns in documented cases. Because thieves oil contains cinnamon, the entire blend needs heavy dilution.
A safe starting point is 1 to 2 drops of thieves oil per tablespoon of a carrier oil like coconut, jojoba, or sweet almond oil. Rub this mixture onto the soles of your feet or across your chest. The feet are a common application site because the skin there is thicker and less prone to irritation. If you apply it to your chest, keep it well away from your face and avoid any broken or irritated skin. Always do a patch test on a small area of your inner forearm first and wait 24 hours to check for redness or irritation before applying more broadly.
Why You Should Avoid Swallowing It
You may have seen advice to add a drop of thieves oil to water or tea and drink it. This is risky for several reasons. Essential oils don’t dissolve in water, so dropping oil into a glass of water is essentially the same as swallowing it undiluted, which can burn your mouth, throat, and stomach lining. When you ingest essential oils, roughly 95% of the active compounds reach your bloodstream unchanged, compared to about 5% through skin and 50% through inhalation. That high concentration can overwhelm your liver’s ability to process the compounds, potentially leading to liver stress or toxicity.
Ingested essential oils can also interact with medications, either amplifying or reducing their effects in unpredictable ways. The Tisserand Institute, a leading authority on essential oil safety, states that oral use of essential oils should only happen under the direct guidance of an aromatherapist specifically trained in internal dosing, who can determine the right oil, dose, duration, and delivery method for a specific situation.
Keep It Away From Children
Two of the five oils in the thieves blend, eucalyptus and rosemary, contain a compound called 1,8-cineole that can irritate the mucous membranes of young children and slow their breathing. The International Federation of Professional Aromatherapists recommends that both eucalyptus and rosemary (in its cineole-rich form) not be diffused near infants or young children, and never applied to or near their faces. If you’re diffusing thieves oil while sick and have small children at home, use it only in a room they won’t be spending time in.
Serious Risks for Cats and Dogs
Three of the five ingredients in thieves oil (clove, cinnamon, and eucalyptus) are known to be toxic to cats. Cats lack a key liver enzyme needed to break down and eliminate certain compounds found in essential oils, making them especially vulnerable. Even passive exposure from a diffuser can be harmful: the oil microdroplets settle on a cat’s fur, and the cat ingests them during grooming. Symptoms of essential oil poisoning in cats include drooling, vomiting, tremors, difficulty breathing, and in severe cases, liver failure.
If you have cats, do not diffuse thieves oil in any room your cat can access. Dogs are somewhat more resilient but can still experience irritation and toxicity from concentrated essential oils, so keep diffusers out of reach and ensure good ventilation.
What Thieves Oil Can and Can’t Do
Thieves oil can make you feel more comfortable when you’re sick. The eucalyptus and rosemary help open congested airways. The clove and cinnamon create a warming sensation that many people find soothing. A frequently cited 1997 study from Weber State University reported that the thieves oil blend killed 99.96% of airborne bacteria in a test environment. That’s an impressive number, but killing bacteria in a controlled lab setting is very different from treating an infection in your body. Most colds and flus are caused by viruses, not bacteria, so antimicrobial properties have limited relevance to most seasonal illnesses.
Think of thieves oil as a comfort measure, not a treatment. It can help you breathe easier, make your room smell better than the inside of a tissue box, and provide a warming sensory experience while your immune system does the actual work of fighting off your illness. Use it safely, dilute it properly, and keep it away from kids and pets.