Compound Monograph
Citronellal
Citronellal is a monoterpene aldehyde with a fresh lemon-citronella scent, used in fragrances and insect repellents.
Classification
Citronellal is a monoterpene aldehyde, part of the terpenoids class. The largest class of plant compounds, built from five-carbon isoprene units — the essential-oil aromatics, resins, bitter principles, saponins, and plant sterols.
Where Does It Come From? (7)
Citronellal is a naturally occurring monoterpene aldehyde, found in Lemon balm, Citronella grass, Lemon eucalyptus and 4 other sources. It is well tolerated orally (low toxicity).
Research & Evidence
Citronellal is a monoterpene aldehyde and a major component of citronella and lemon eucalyptus oils, also present in lemon balm. It carries a fresh, lemony scent and is used in perfumery and as an active ingredient in some natural insect repellents. Laboratory studies report antifungal and antimicrobial activity.
Toxicity & Safety
Citronellal is used in fragrances and repellents and is generally well tolerated, though, like many essential-oil aldehydes, it can be a skin irritant and contact allergen in concentrated form. A detailed isolated-compound safety profile in humans is limited.