Lavender as an Anxiolytic
Lavender oil (from Lavandula angustifolia) is an approved substance in Germany for the treatment of anxiety and restlessness. Human and in vivo studies indicate that lavender may possess anxiety-lowering, mood-stabilizing, sedative, analgesic, anticonvulsive, and neuroprotective properties. Lavender has been shown to enhance the effect of serotonin, a mood-regulating chemical, in the brain.
Evidence from clinical trials shows that oral use of lavender oil can help reduce symptoms of generalized anxiety disorder (GAD), posttraumatic stress disorder, and chronic fatigue (neurasthenia).[3–5] Effects were similar to that obtained by anxiolytic medications (SSRI pareoxetine)  and lorazepam, with fewer adverse effects. Lavender oil significantly improved quality and duration of sleep, and improved mental health without causing oversedation.[6, 7]
Two important clinical trials to date suggest that there is a relatively small chance of interactions between lavender oil and several medications. First, a randomized, double-blind, crossover trial examining the effect of lavender oil on liver enzyme induction found that oral use of lavender oil at 160 mg for 11 days had no effect on cytochrome CYP enzymes, which are major pathways for drug activation, metabolism, and elimination: CYP1A2, 2C9, 2D6, and 3A4 activity. Secondly, a recent clinical trial demonstrated lack of interaction between lavender oil (Silexan) and markers assessing the effectiveness of hormonal contraception.
- Koulivand, P.H., M. Khaleghi Ghadiri, and A. Gorji. “Lavender and the nervous system.” Evidence-Based Complementary and Alternative Medicine Vol. 2013 (2013): 681304.
- Baldinger, P., et al. “Effects of Silexan on the serotonin-1A receptor and microstructure of the human brain: A randomized, placebo-controlled, double-blind, cross-over study with molecular and structural neuroimaging.” International Journal of Neuropsychopharmacology Vol. 18, No. 4 (2014): pii: pyu063.
- Kasper, S., et al. “Lavender oil preparation Silexan is effective in generalized anxiety disorder—A randomized, double-blind comparison to placebo and paroxetine.” International Journal of Neuropsychopharmacology Vol. 17, No. 6 (2014): 859–869.
- Woelk, H. and S. Schläfke. “A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder.” Phytomedicine Vol. 17, No. 2 (2010): 94–99.
- Uehleke, B., et al. “Phase II trial on the effects of Silexan in patients with neurasthenia, post-traumatic stress disorder or somatization disorder.” Phytomedicine Vol. 19, No. 8–9 (2012): 665–671.
- Kasper, S., et al. “Silexan, an orally administered Lavandula oil preparation, is effective in the treatment of ‘subsyndromal’ anxiety disorder: a randomized, double-blind, placebo controlled trial.” International Clinical Psychopharmacology Vol. 25, No. 5 (2010): 277–287.
- Kasper, S., et al. “Efficacy and safety of silexan, a new, orally administered lavender oil preparation, in subthreshold anxiety disorder—Evidence from clinical trials.” Wiener Medizinisch Wochenschrift Vol. 160, No. 21–22 (2010): 547–556.
- Doroshyenko, O., et al. “Drug cocktail interaction study on the effect of the orally administered lavender oil preparation silexan on cytochrome P450 enzymes in healthy volunteers.” Drug Metabolism and Disposition Vol. 41, No. 5 (2013): 987–993.
- Heger-Mahn, D., et al. “No interacting influence of lavender oil preparation silexan on oral contraception using an ethinyl estradiol/levonorgestrel combination.” Drugs in R&D Vol. 14, No. 4 (2014): 265–272.