Study summary
Effectiveness of citronella preparations in preventing mosquito bites: systematic review of controlled laboratory experimental studies
Kongkaew C, Sakunrag I, Chaiyakunapruk N, Tawatsin A
Read the original paper- Study type
- Review
- Year
- 2011
- Species tested
- Aedes, Anopheles, Culex (laboratory)
- Published in
- Tropical Medicine & International Health 16(7):802-810
- Evidence strength
- Well-supported evidence
How it was tested
The authors searched five medical databases for cage- and room-method laboratory experiments and pooled the cage-method results to estimate how citronella's protection time compares with DEET.
Summary
A systematic review asking how well citronella actually prevents mosquito bites, pulling together every controlled laboratory experiment that pitted a citronella preparation against a control. Eleven studies qualified, covering citronella oil alone and citronella combined with vanillin as a fixative, all benchmarked against DEET.
Key findings
Citronella protects for much less time than DEET. In the pooled analysis, citronella oil's complete protection against Aedes fell short of DEET by about 253 minutes, roughly four hours less. Adding vanillin as a fixative extended protection meaningfully, enough that citronella-plus-vanillin approached DEET against Anopheles and Culex, and room-method tests showed at least three hours of complete repellency for the fixed formulations. The verdict: plain citronella is weak and short-lived next to DEET, but formulation, and a fixative in particular, makes a real difference.
Limitations
The evidence is laboratory-only, so it does not capture outdoor wind, sweat, and reapplication, and 'citronella preparations' span a wide range of oils, concentrations, and fixative combinations, so no single number describes them all.