Study summary
Comparative repellency of 38 essential oils against mosquito bites
Trongtokit Y, Rongsriyam Y, Komalamisra N, Apiwathnasorn C
Read the original paper- Study type
- Lab
- Year
- 2005
- Species tested
- Aedes aegypti
- Published in
- Phytotherapy Research 19(4):303-309
- Evidence strength
- Well-supported evidence
How it was tested
Laboratory screening of 38 essential oils on human skin at multiple dilutions against Aedes aegypti.
Summary
A large laboratory screen ranking 38 essential oils by how well they stop Aedes aegypti biting treated human skin. It is one of the most-cited head-to-head botanical comparisons, and its main lesson is that most oils lose nearly all their repellency once diluted.
Key findings
At 10% and 50%, not one of the 38 oils prevented bites for the full two hours. Only four, all undiluted, gave complete protection for the whole window: citronella, patchouli, clove, and makaen. The other 34 fell short. Because the test stopped at two hours, even the top four are only known to last at least that long, and undiluted oils are impractical and irritating for everyday skin use.
Limitations
The window was capped at two hours so the best oils' true duration is unknown, only one mosquito species was used, and the effective concentrations were undiluted oils that are not practical to wear.