Eucalyptus oil’s history of medicinal use dates back to the days of Indigenous Australians, who used both the leaves and the roots of the plant as medicines. When English colonists began to arrive in Australia in the late 1700s, they quickly adopted eucalyptus oil as a medicinal treatment themselves. In fact, when Surgeon-General John White arrived in 1788, he took an interest in eucalyptus almost immediately, according to entries in his diary. By 1790, he had distilled a quart of eucalyptus oil and sent it back to England for testing, where it eventually came to be used as a disinfectant to clean wounds and aid in healing after surgery. The anti-inflammatory properties of eucalyptus oil4 may be to thank for these pain-relieving properties. (A 2010 study found that eucalyptus oil reduced the expression of the inflammatory COX-2 enzyme by at least 25%.) For those with infected toenails in particular, eucalyptus may “provide an acceptable and cheaper alternative to prescription topical antifungal agents,” according to one study in the Journal of Foot and Ankle Research7. Eucalyptus oil may also be an effective natural treatment for head lice. One 2017 study9 from Australia, for example, found that using eucalyptus oil in a solution with lemon tea tree oil was twice as effective as the common chemical pesticide treatment piperonyl butoxide. Another previous study found that eucalyptus oil could actually protect human hair10 from the invasion of head lice for at least seven hours. You can also add eucalyptus essential oil to your bath for a steamy, sauna-like experience. Try this: Add about 1 to 2 cups of Epsom salts along with 1 tablespoon of a carrier oil (you can use coconut, jojoba, or sweet almond, among others) to a tub of warm water before adding no more than 3-6 drops of eucalyptus essential oil and swirling the bathwater before you jump in. If you want to treat dandruff, you can add a couple of drops of eucalyptus oil to your shampoo. Or, combine 2-3 drops of eucalyptus oil with a carrier oil and massage directly into your scalp. Allow to sit about 30 minutes before shampooing. Here’s more information on how to use essential oils for lice. As mentioned above, you can also add 1 drop of eucalyptus oil to your toothpaste before brushing to promote gum health, or create a mouth rinse by diluting 1 drop of eucalyptus oil with olive or coconut oil. However, you should never swallow eucalyptus oil. Most essential oils, including eucalyptus oil, are far too caustic to be applied directly to the skin without a carrier oil. If you do so, you will likely experience significant irritation. Finally, there’s always the potential for allergic reactions to eucalyptus oil17, especially with topical use. If you’re allergic to tea tree oil, you will likely be allergic to eucalyptus oil, since they contain many of the same compounds18.
