In broad terms, “eucalyptus” refers to some 700 plant species that are known for their oily and odiferous leaves. While this term may be used as shorthand for “lemon eucalyptus” (a derivative of the Corymbia citriodora or lemon-scented gum tree) it may also be referring to so-called “standard eucalyptus” (a derivative of Eucalyptus globulus or the southern blue gum tree). Though both have been studied for their insect repellant qualities, lemon eucalyptus has shown the most effectiveness and commercial use, consequently.
For example, one field study in Bolivia found a 30% PMD topical application of Corymbia citriodora oil to be ~97% effective in blocking mosquitos for a full 4 hours. Similarly, a field study in Tanzania found that 50% PMD topical application of the same oil provide a 100% efficiency rating for up to 7 hours against several disease-carrying mosquito species. Even laboratory studies have backed up lemon eucalyptus oil’s credibility, with one test of a 20% PMD topical application providing 100% protection from mosquitos for up to 12 hours (1).
This broad range of successful implementation has elicited further study into the active, insect-blocking ingredients inherent to lemon eucalyptus oil’s chemical composition. Researchers have found a compound called PMD (short for para-menthane 3, 8 diol) to be the most scientific relevant due to its high protection rating paired with a low volatility rating. This latter factor implies that essential oils containing descent concentrations of PMD do not evaporate rapidly, allowing the active ingredients to remain effective for up to several hours. (1).
In additional, lemon eucalyptus oil in particular, often contains citronella within its botanical makeup. Citronella is already widely used as a generally effective natural mosquito repellant, making commercial products that use lemon eucalyptus oil as a base among the most effective overall (2).
With regards to safety, lemon eucalyptus oil has only one noteworthy drawback (when used according to instructions). Currently, the US Environmental Protection Agency does not certify lemon eucalyptus oil’s efficiency as an insect repellant. While this does not mean that this essential oil is any more dangerous than its competitors, it does mean that it has not been extensively tested for safety by a US-based regulating authority.
While the natural mosquito repellant alternative market is bursting with differentiated options, few can currently compare to the proven effectiveness (both in field and laboratory testing) of lemon eucalyptus oil. With viable options in consumer-grade spray forms, lemon eucalyptus oil holds perhaps the most viable solution to decreasing you and your family’s use of DEET-based insect repellants. If any natural insect repellant were to receive a full commendation, lemon eucalyptus oil would come the closest to earning all five stars.
Also, a great deal of lemon eucalyptus oil’s potential use as a DEET-alternative derives from its present usage in a broad range of consumer-grade products. Several major brands currently produce lemon eucalyptus oil sprays, most of which are lauded for their comparable effectiveness when it comes to dissuading mosquitos as well as their fresh, citrusy scent. For this reason, lemon eucalyptus oil holds the greatest implementation potential among those that do not wish to dabble with other essential oils or grow their own insect repellant plants.
Forms of Lemon Eucalyptus and Where to Get Them
Lemon eucalyptus oil derives from the leaves and bark of the Corymbia citriodora, a native of tropical regions in north eastern Australia. As a result, growing your own independent lemon eucalyptus oil source would be challenging if a grove does not already exist in your area.
Lemon eucalyptus oil’s most popular implementation remains within spray-type products that maximize the active ingredient’s efficiency over a user’s entire body. As the oil’s name implies, these products are often marketed for their sweet, lemony scents, as well as their lack of “harsh” chemicals such as DEET. These sprays can be purchased in most outdoor goods stores as well as online.
1 – Marta Ferreira Maia and Sarah J Moore. Plant-based insect repellents: a review of their efficacy, development and testing. Published online 2011 Mar 15. doi: 10.1186/1475-2875-10-S1-S11
2 – Consumer Reports. Do ‘Natural’ Insect Repellents Work?. Consumer Reports. May 20 2019.
Other Essential Oils as Mosquito Repellents
Checkout our analysis of other essential oils as natural mosquito repellents: