Effects of orally administered lavender essential oil on responses to anxiety-provoking film clips

Background Lavender odour is commonly used to alleviate mild anxiety. Double blind studies are difficult to conduct with odours, and there are few reliable investigations of lavender's efficacy. Method Orally administered lavender capsules (placebo, 100, 200 mu l) were tested in a randomised between-subjects (n = 97) double-blind study. Film clips were used to elicit anxiety. Measures included anxiety, State Trait Anxiety Inventory (STAI), mood, positive and negative affect scale (PANAS), heart rate (HR), galvanic skin response (GSR), and heart rate variation (HRV). Following baseline measurements capsules were administered. Participants viewed a neutral film clip, then an anxiety-provoking and light-hearted recovery film clip. Results For the 200 mu l lavender dose (luring the neutral film clip there was a trend towards reduced state anxiety, GSR and HR and increased HRV. In the anxiety-eliciting film, lavender was mildly beneficial in females but only on HRV measures. In males sympathetic arousal increased during the anxiety film (GSR). HRV significantly increased at 200 mu l during all three film clips in females, suggesting decreased anxiety. Conclusion These findings suggest that lavender has anxiolytic effects in humans under conditions of low anxiety, but these effects may not extend to conditions of high anxiety. Copyright (C) 2009 John Wiley & Sons, Ltd.