Oil of Lemon Eucalyptus (OLE) is an extract derived from the leaves of the lemon eucalyptus tree, Corymbia citriodora, native to Australia. The extract is processed to increase the concentration of its active compound, resulting in a highly effective insect repellent. This refined extract is chemically enhanced to contain high levels of para-Menthane-3,8-diol (PMD). Products containing OLE/PMD are distinctly different from the standard Lemon Eucalyptus Essential Oil (EO) that is simply steam-distilled from the leaves. The commercially available repellent is the OLE/PMD version.
The Premier Plant-Based Insect Repellent
The primary use of Oil of Lemon Eucalyptus is as a highly effective, plant-derived insect repellent. The active ingredient, PMD, is recognized by public health organizations as one of the few non-synthetic compounds offering protection comparable to DEET. PMD interferes with the insect’s sensory system by masking environmental cues, such as carbon dioxide and lactic acid, that biting insects use to locate a host.
This repellent action is effective against a wide range of pests, including mosquitoes, ticks, biting flies, and gnats. Protecting against mosquitoes is important because they can transmit serious pathogens, including the viruses responsible for West Nile and Zika. Ticks, which can carry Lyme disease and Rocky Mountain spotted fever, are also effectively repelled by OLE/PMD products.
A high concentration of PMD (30%) provides over 95% protection against mosquitoes for up to three hours. Protection duration from commercial OLE/PMD products is typically cited as lasting up to six hours. The CDC lists OLE/PMD as the only plant-based active ingredient recommended for repelling disease-transmitting insects, confirming its status as a reliable, naturally derived alternative.
Safe Application and Usage Guidelines
When using OLE/PMD products, follow specific safety and application guidelines to maximize effectiveness and minimize irritation. Apply the product only to exposed skin and clothing, and never use it under clothing. Avoid applying the repellent near the eyes and mouth, and do not use it on cuts, wounds, or irritated skin.
For children, spray the product onto an adult’s hands first, then rub it onto the child. Avoid applying it to their hands entirely, as children frequently put their hands in their mouths.
OLE and PMD products should not be used on children under the age of three years. No insect repellent should be used on infants younger than two months; alternative protective measures like mosquito netting and clothing should be employed. EPA-registered OLE/PMD repellents are considered safe for pregnant and breastfeeding women when label instructions are followed.
Only commercially formulated OLE/PMD is recommended for insect control, as the raw essential oil lacks the necessary PMD concentration. Consumers should use only EPA-registered products. After returning indoors, wash the treated skin and clothing with soap and water. When combining OLE/PMD with sunscreen, the sunscreen must always be applied first, followed by the insect repellent.
Secondary Applications in Home and Health
Beyond its primary function as a repellent, Lemon Eucalyptus essential oil (EO) has several secondary uses. These applications are traditionally associated with the unrefined essential oil, not the OLE/PMD extract.
The EO is valued in aromatherapy for its strong, fresh, lemony aroma. When diffused, the scent is utilized to help uplift mood, clear mental fog, and act as a natural air freshener.
In traditional health practices, the essential oil has been employed topically, diluted in a carrier oil, for its soothing properties. The oil contains citronellal, which is known to have anti-inflammatory effects. This makes it a traditional choice for relief from minor muscle aches, joint discomfort, and sprains.
The essential oil exhibits mild antiseptic and antifungal properties, leading to its traditional use for cleaning surfaces and treating minor skin irritations. These applications rely on the EO, not the high PMD concentration of the OLE extract.