Bergamot essential oil is cold-pressed from the rind of the Citrus bergamia fruit, primarily cultivated in Italy. Recognized for its bright, complex aroma, the oil is used for flavoring tea and in aromatherapy blends. The oil’s volatile compounds have been studied for various biological activities, including their potential to deter insects. Due to growing consumer interest in plant-based alternatives, scientific investigation has focused on bergamot oil to determine its effectiveness against mosquitoes and provide reliable protection from biting insects.
Scientific Findings on Repellency
Laboratory studies confirm that bergamot essential oil repels mosquitoes, though efficacy varies significantly by species. In controlled arm-in-cage assays, the undiluted oil provided moderate protection against the yellow fever mosquito (Aedes aegypti) and the malaria carrier (Anopheles dirus), offering a median complete-protection time of approximately 90 minutes for both.
The oil showed greater promise against the common house mosquito (Culex quinquefasciatus), a vector for diseases like West Nile fever. Against this species, the median protection time extended to 210 minutes, suggesting species-specific variation in repellency. Bergamot oil generally offers a shorter duration of effectiveness compared to established repellents and requires more frequent reapplication. The quality and chemical composition of the specific oil batch can also cause variability in performance.
Key Chemical Compounds in Bergamot
The repellent action of bergamot oil originates from its complex mixture of volatile organic compounds, primarily monoterpenes. Key molecules responsible for deterring insects include linalool, limonene, and linalyl acetate. Linalool is an alcohol known to have insect-repelling properties.
Limonene is a monoterpene that contributes to the strong citrus scent and acts as a mild repellent. These chemicals interfere with the olfactory systems of mosquitoes. They may target certain chemoreceptors, such as the transient receptor potential ankyrin 1 (TRPA1) channel, disrupting the mosquito’s ability to locate a host by confusing their sense of smell.
Practical Application and Safety Precautions
The most significant practical concern when using bergamot oil as a personal repellent is its phototoxicity. The oil contains naturally occurring furocoumarins, notably bergapten, which are potent photosensitizers. If applied to the skin and exposed to ultraviolet A (UVA) light, it can cause a severe phototoxic reaction.
This reaction results in painful skin damage, including blistering, erythema, and long-lasting hyperpigmentation. To prevent this, bergamot oil must be diluted to very low concentrations with a carrier oil, such as coconut oil, before topical application. A safer alternative is using bergapten-free (FCF) bergamot oil, where the phototoxic furocoumarins have been removed. Consumers can also avoid risk by applying diluted oil only to covered skin or by using the oil for diffusion rather than direct topical application.