How to Use Eucalyptus Oil Safely and Beneficially

Eucalyptus oil is distilled from leaves of select species of eucalyptus trees (most commonly Eucalyptus globulus), which are native to Australia. The fragrance of the trees — and the oil — is described variously as bright, woody, coniferous, camphoraceous, crisp and refreshing. Some say a whiff of eucalyptus oil has a medicinal scent. The oil’s biological properties are wide-ranging, according to the National Institutes of Health, from antimicrobial and antiseptic to insecticidal. It is lethal to mites, repels insects and even removes grease, the NIH says.

For all its good properties and uses, remember that eucalyptus oil is very potent. “It is important to note that Eucalyptus globulus should be used with caution in young children due to the potential for central nervous system and breathing problems,” says Blaire Morriss, a nurse practitioner and certified aromatherapist. The National Institutes of Health lists several warnings: Eucalyptol, a chemical found in the oil, is “possibly unsafe applied directly to skin without being diluted, and can cause serious problems with the nervous system." Ingesting the oil could have severe consequences. Signs of eucalyptus poisoning might include stomach pain and burning, dizziness, muscle weakness, small eye pupils and feelings of suffocation. "Eucalyptus oil can also cause nausea, vomiting and diarrhea,” the NIH warns.

“When you say eucalyptus, the first thing you think of is a decongestant,” says Cary Caster, a clinically certified aromatherapist who teaches aromatherapy courses through the Osher Center for Integrative Management at the University of Miami. Eucalyptus is a common ingredient in cough drops, chest rubs and other over-the-counter products that claim to reduce coughing and nasal congestion due to colds. The science behind it is complex; it’s the oil’s naturally occurring components – 1,8-cineole and menthone – that give eucalyptus its punch. “With its antimicrobial properties, that makes it wonderful as a chest rub and decongestant, as well as being great for inhaling,” Caster says. A note of caution: “Always dilute, dilute, dilute!” Caster warns. Eucalyptus oil is very potent, and a tiny bit, diluted with a carrier substance, goes a long, long way. “I always use organic jojoba for my carrier. It’s the most like our skin’s sebum so it’s nourishing to the skin, and since it’s actually a liquid wax – not a true oil – it extends the shelf life of the essentials oils.” A dilution of 1-3% essential oil to 97-99% carrier is safe to apply to skin, she says.

While many people are familiar with the term "aromatherapy" as something with a pleasant scent, the therapeutic effects of essential oils make aromatherapy much more than that, says Blaire Morriss, a nurse practitioner, certified aromatherapist and owner of The Oil Jar in Nashville. “Aromatherapy, or essential oil therapy, is the intentional use of essential oils for therapeutic purposes,” Morriss explains. “I tend to use eucalyptus oil for all things respiratory, particularly when there is congestion, coughing and feeling run down. I will also use it at times for muscular tension, mixed with lavender oil and peppermint. And it’s a great oil for clearing the atmosphere and mind and helps to give a sense of being refreshed.”

“Eucalyptus oil is one of the more common essential oils used by massage therapists,” says Kate Sutherland, a licensed massage therapist in Nashville, Tennessee. “Massage therapists use eucalyptus both as a stand alone scent or blended with other essential oils – peppermint and lavender are frequent choices – added to the therapist’s massage oil or lotion.” The scent is soothing, and also helps open the airway passages, so it is a top choice to diffuse near the headrest of the massage table, or to add to hot towels rolled under the neck or draped over the back or feet, Sutherland says.

If you’re worried about house dust mites in your child’s teddy bear and other plush toys, eucalyptus oil can help ease your mind. The National Institutes of Health notes that sleeping with soft toys is a significant risk factor for sensitization to house dust mites, and studied the efficacy of eucalyptus oil in eliminating them. Their findings: washing soft toys in water with 0.2% to 0.4% eucalyptus oil resulted in a significant reduction in live dust mites, as well as dust mite allergens.

There are several species of eucalyptus trees used for oil production; Eucalyptus globulus is the most common, but botanist, clinical aromatherapist and licensed massage therapist Cary Caster, who teaches courses in aromatherapy, uses oil distilled from E. citriodora to make a bug repellent spray. Caster’s recipe is a mixture of lemon verbena and rose geranium hydrosols (scented water), aloe vera gel and distilled water, with Eucalyptus citriodora, cedarwood and patchouli essential oils making up 2% of the mixture. “It smells like lemongrass or citronella,” Caster says. “I use it for most biting insects outdoors — fleas, ticks, mosquitos, gnats and so forth — but it is also useful for repelling ants and other crawlers around doorways and crevices,” she says.

A study in the journal Microbios shows that eucalyptus oil is an effective antibacterial agent against several strains of bacteria and fungi. Sam Chavez, owner of Happy Day Cleaning a plant-based cleaning service in Nashville, Tennessee, makes plant-based sprays with eucalyptus oil to use in clients’ kitchens and bathrooms because of its antiseptic and antimicrobial properties, sometimes mixing it with other essential oils. “It does a great job at disinfecting and leaving the space with a calming and invigorating aroma,” she says. “I usually use it alone. When I do mix it, my favorite blends are eucalyptus/lavender and eucalyptus/lemon.”

The scent of eucalyptus is a common fragrance in scented candles for use throughout the house, often paired with other soothing scents – spearmint, orange, lavender, lemon or other compatible fragrances. “I like it best in an air diffuser,” says Kate Sutherland, a massage therapist at Basic Kneads Advanced Massage Therapy in Nashville. “We use it in our steam shower at work, putting a couple of drops above the steam element. And sometimes I flick a couple of drops on the shower tile at home.”