Two essential oils derived from
Lavandula angustifolia and
Lavandula ×
intermedia were investigated for any antiparasitic activity against the human protozoal pathogens
Giardia duodenalis and
Trichomonas vaginalis and the fish pathogen
Hexamita inflata: all of which have significant infection and economic impacts. The study has demonstrated that low (≤1%) concentrations of
L. angustifolia and
L. ×
intermedia oil can completely eliminate
T. vaginalis,
G. duodenalis and
H. inflata in vitro. At 0.1% concentration,
L. angustifolia oil was found to be slightly more effective than
L ×
intermedia oil against
G. duodenalis and
H. inflata. The potential applications are discussed.