Citral
2,6-Octadienal, 3,7-dimethyl-
Citral is the lemon-scented aldehyde (geranial plus neral) that gives lemongrass and lemon myrtle their punch, and much of their repellency. On its own it repels strongly per dose but does not last, because it evaporates fast.
How it works
Citral masks the odor cues mosquitoes track and can match or beat DEET at equal concentration in short lab tests. Its volatility is the catch: without a fixative it wears off within an hour or two.
Safety around dogs & cats
The main aldehyde in lemongrass and a known irritant; the parent oils are on the ASPCA feline-toxic list. Do not apply to cats and keep cats off treated skin. Dogs handle it better but should not wear it.
Low confidence. Ratings from ASPCA Animal Poison Control, the Pet Poison Helpline, and published veterinary toxicology. This is general information, not veterinary advice. If your pet is exposed, call your vet or the ASPCA Animal Poison Control Center at (888) 426-4435.
The evidence
Constituent screens rank citral among the stronger natural repellents by contact, but skin complete-protection-time is short, roughly one to two hours, reaching around three only in optimized higher-strength formulations. It is best understood as the working part of lemongrass oil rather than a long-lasting active on its own.
- Topical mosquito repellency of a Litsea cubeba essential oil spray against Aedes aegypti, Anopheles dirus, and Culex quinquefasciatus2026LabLimited evidence
Laboratory efficacy and short-term skin-tolerability study of a ready-to-use topical spray (MosShield) containing 6% w/w Litsea cubeba essential oil, the citral-rich oil pressed from may chang fruit. Repellency was measured with the WHO arm-in-cage complete-protection-time protocol against three medically important mosquito species, and dermal tolerability was checked with a human skin-patch test in 48 healthy volunteers.
Products using it
Regulatory notes
Source: EPA SRS active ingredient list export. Minimum risk (25(b)) status is applied separately when applicable.
Safety notes
Citral is a well-known skin sensitizer and is restricted in fragrance for that reason, so it needs careful dilution. Keep citrus-type terpene oils away from cats.