Claims have long circulated about lavender's ability to prevent balding, control mild burns and acne, as well as treat gastrointestinal disorders. But lavender's impact on mood and cognition has garnered the most attention. A study by researchers at Charles Sturt University in Australia reviewed trials testing the outcomes of lavender aromatherapy. It seems there is mounting evidence that the essential oil does have physiological effects.
To measure the effects of aromatherapy, researchers compared responses with two essential oils thought to have opposite effects on alertness: soothing lavender and invigorating rosemary. One University of Miami study followed brain activity with an EEG machine, finding that the group subjected to lavender aromatherapy did in fact show brainwaves suggesting drowsiness, while the group subjected to rosemary experienced increased alertness.