There is much scientific research on this topic. Several human studies across a wide variety of settings with a diverse array of populations have demonstrated the calming effects of inhaling lavender aroma. Lavender aromatherapy has shown to lower blood pressure and relax the sympathetic nervous system. Studies have also measured a positive effect on mood: reducing depression, anxiety, and stress through the inhalation of this essential oil. The active constituent(s) demonstrating a calming effect are linalool  , and a synergistic effect of linalool in combination with linalyl acetate. The activation of serotonergic neurotransmission in the brain may play a role in lavender’s anxiolytic properties.
 Umezu, T., Nagano, K., Ito, H., Kosakai, K., Sakaniwa, M., & Morita, M. (2006). Anticonflict effects of lavender oil and identification of its active constituents. Pharmacology Biochemistry and Behavior, 85(4), 713-721.
 Elisabetsky, E., Marschner, J., & Souza, D. O. (1995). Effects of linalool on glutamatergic system in the rat cerebral cortex. Neurochemical research, 20(4), 461-465.
 Takahashi, M., Satou, T., Ohashi, M., Hayashi, S., Sadamoto, K., & Koike, K. (2011). Interspecies comparison of chemical composition and anxiolytic-like effects of lavender oils upon inhalation. Natural product communications, 6(11), 1769-1774.
 Takahashi, M., Yamanaka, A., Asanuma, C., Asano, H., Satou, T., & Koike, K. (2014). Anxiolytic-like effect of inhalation of essential oil from Lavandula officinalis: investigation of changes in 5-HT turnover and involvement of olfactory stimulation. Natural product communications, 9(7), 1023-1026.
 Sanders, C., Diego, M., Fernandez, M., Field, T., Hernandez-Reif, M., & Roca, A. (2002). EEG asymmetry responses to lavender and rosemary aromas in adults and infants. International Journal of Neuroscience, 112(11), 1305-1320.
 Itai, T., Amayasu, H., Kuribayashi, M., Kawamura, N., Okada, M., Momose, A., … & Kaneko, S. (2000). Psychological effects of aromatherapy on chronic hemodialysis patients. Psychiatry and Clinical Neurosciences, 54(4), 393-397.
 Louis, M., & Kowalski, S. D. (2002). Use of aromatherapy with hospice patients to decrease pain, anxiety, and depression and to promote an increased sense of well-being. American Journal of Hospice and Palliative Medicine, 19(6), 381-386.
 Kutlu, A. K., Yılmaz, E., & Çeçen, D. (2008). Effects of aroma inhalation on examination anxiety. Teaching and Learning in Nursing, 3(4), 125-130.
 Toda, M., & Morimoto, K. (2008). Effect of lavender aroma on salivary endocrinological stress markers. Archives of oral biology, 53(10), 964-968.
 Burnett, K. M., Solterbeck, L. A., & Strapp, C. M. (2004). Scent and mood state following an anxiety-provoking task. Psychological reports, 95(2), 707-722.
 Imura, M., Misao, H., & Ushijima, H. (2006). The Psychological Effects of Aromatherapy‐Massage in Healthy Postpartum Mothers. Journal of Midwifery & Women’s Health, 51(2), e21-e27.
 Holmes, C., Hopkins, V., Hensford, C., MacLaughlin, V., Wilkinson, D., & Rosenvinge, H. (2002). Lavender oil as a treatment for agitated behaviour in severe dementia: a placebo controlled study. International journal of geriatric psychiatry, 17(4), 305-308.
 Lin, P. W. K., Chan, W. C., Ng, B. F. L., & Lam, L. C. W. (2007). Efficacy of aromatherapy (Lavandula angustifolia) as an intervention for agitated behaviours in Chinese older persons with dementia: a cross‐over randomized trial. International journal of geriatric psychiatry, 22(5), 405-410.
 Conrad, P., & Adams, C. (2012). The effects of clinical aromatherapy for anxiety and depression in the high risk postpartum woman–a pilot study. Complementary therapies in clinical practice, 18(3), 164-168.
 Hwang, J. H. (2006). The effects of the inhalation method using essential oils on blood pressure and stress responses of clients with essential hypertension. Taehan Kanho Hakhoe Chi, 36(7), 1123-1134.
 Park, M. K., & Lee, E. S. (2004). [The effect of aroma inhalation method on stress responses of nursing students]. Taehan Kanho Hakhoe Chi, 34(2), 344-351.
 Grunebaum, L. D., Murdock, J., Castanedo‐Tardan, M. P., & Baumann, L. S. (2011). Effects of lavender olfactory input on cosmetic procedures. Journal of cosmetic dermatology, 10(2), 89-93.
 Muzzarelli, L., Force, M., & Sebold, M. (2006). Aromatherapy and reducing preprocedural anxiety: A controlled prospective study. Gastroenterology Nursing, 29(6), 466-471.
 Motomura, N., Sakurai, A., & Yotsuya, Y. (2001). Reduction of mental stress with lavender odorant. Perceptual and motor skills, 93(3), 713-718.
 Duan, X., Tashiro, M., Wu, D. I., Yambe, T., Wang, Q., Sasaki, T., … & Itoh, M. (2007). Autonomic nervous function and localization of cerebral activity during lavender aromatic immersion. Technology and Health Care, 15(2), 69-78.
 Hoya, Y., Matsumura, I., Fujita, T., & Yanaga, K. (2008). The use of nonpharmacological interventions to reduce anxiety in patients undergoing gastroscopy in a setting with an optimal soothing environment. Gastroenterology Nursing, 31(6), 395-399.
 Kritsidima, M., Newton, T., & Asimakopoulou, K. (2010). The effects of lavender scent on dental patient anxiety levels: a cluster randomised‐controlled trial. Community dentistry and oral epidemiology, 38(1), 83-87.
 Field, T., Field, T., Cullen, C., Largie, S., Diego, M., Schanberg, S., & Kuhn, C. (2008). Lavender bath oil reduces stress and crying and enhances sleep in very young infants. Early human development, 84(6), 399-401.
 Heuberger, E., Redhammer, S., & Buchbauer, G. (2004). Transdermal Absorption of ()-Linalool Induces Autonomic Deactivation but has No Impact on Ratings of Well-Being in Humans. Neuropsychopharmacology, 29(10).
 Cha, J. H., Lee, S. H., & Yoo, Y. S. (2010). Effects of Aromatherapy on Changes in the Autonomic Nervous System, Aortic Pulse Wave Velocity and Aortic Augmentation Index in Patients with Essential Hypertension. Journal of Korean Academy of Nursing, 40(5).
 Kim, I. H., Kim, C., Seong, K., Hur, M. H., Lim, H. M., & Lee, M. S. (2012). Essential oil inhalation on blood pressure and salivary cortisol levels in prehypertensive and hypertensive subjects. Evidence-Based Complementary and Alternative Medicine, 2012.
 MPham, W. S., & Siripornpanich, V. (2012). The effects of lavender oil inhalation on emotional states, autonomic nervous system, and brain electrical activity. J Med Assoc Thai, 95(4), 598-606.
 Kim, S., Kim, H. J., Yeo, J. S., Hong, S. J., Lee, J. M., & Jeon, Y. (2011). The effect of lavender oil on stress, bispectral index values, and needle insertion pain in volunteers. The Journal of Alternative and Complementary Medicine, 17(9), 823-826.
 Kim, M. J., Nam, E. S., & Paik, S. I. (2005). The effects of aromatherapy on pain, depression, and life satisfaction of arthritis patients. Taehan Kanho Hakhoe Chi, 35(1), 186-194.
 Morris, N. (2002). The effects of lavender (Lavendula angustifolium) baths on psychological well-being: two exploratory randomised control trials. Complementary therapies in medicine, 10(4), 223-228.
 Hur, M. H., Oh, H., Lee, M. S., Kim, C., Choi, A. N., & Shin, G. R. (2007). Effects of aromatherapy massage on blood pressure and lipid profile in korean climacteric women. International Journal of Neuroscience, 117(9), 1281-1287.
 Rho, K. H., Han, S. H., Kim, K. S., & Lee, M. S. (2006). Effects of aromatherapy massage on anxiety and self-esteem in korean elderly women: a pilot study. International Journal of Neuroscience, 116(12), 1447-1455.
 Lehrner, J., Marwinski, G., Lehr, S., Johren, P., & Deecke, L. (2005). Ambient odors of orange and lavender reduce anxiety and improve mood in a dental office. Physiology & Behavior, 86(1), 92-95.
 Pemberton, E., & Turpin, P. G. (2008). The Effect of Essential Oils on Work‐Related Stress in Intensive Care Unit Nurses. Holistic nursing practice, 22(2), 97-102.
 McCaffrey, R., Thomas, D. J., & Kinzelman, A. O. (2009). The Effects of Lavender and Rosemary Essential Oils on Test‐Taking Anxiety Among Graduate Nursing Students. Holistic nursing practice, 23(2), 88-93.
 Hongratanaworakit, T. (2011). Aroma-therapeutic effects of massage blended essential oils on humans. Natural product communications, 6(8), 1199-1204.
 Akhondzadeh, S., Kashani, L., Fotouhi, A., Jarvandi, S., Mobaseri, M., Moin, M., … & Taghizadeh, M. (2003). Comparison of Lavandula angustifolia Mill. tincture and imipramine in the treatment of mild to moderate depression: a double-blind, randomized trial. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 27(1), 123-127.
 Chang, S. Y. (2008). Effects of aroma hand massage on pain, state anxiety and depression in hospice patients with terminal cancer. Journal of Korean Academy of Nursing, 38(4), 493-502.
 Kim, M. W., Yoo, Y. S., Cho, O. H., & Jo, S. J. (2009). The effects of aroma inhalation therapy on anxiety and heart rate variability in the patients undergoing urodynamic study. Journal of Korean Biological Nursing Science, 11(1), 32-41.
 Saeki, Y. (2000). The effect of foot-bath with or without the essential oil of lavender on the autonomic nervous system: a randomized trial. Complementary Therapies in Medicine, 8(1), 2-7.
 Gedney, J. J., Glover, T. L., & Fillingim, R. B. (2004). Sensory and affective pain discrimination after inhalation of essential oils. Psychosomatic Medicine, 66(4), 599-606.
 Dunn, C., Sleep, J., & Collett, D. (1995). Sensing an improvement: an experimental study to evaluate the use of aromatherapy, massage and periods of rest in an intensive care unit. Journal of advanced nursing, 21(1), 34-40.
 Xu, F., Uebaba, K., Ogawa, H., Tatsuse, T., Wang, B. H., Hisajima, T., & Venkatraman, S. (2008). Pharmaco-physio-psychologic effect of Ayurvedic oil-dripping treatment using an essential oil from Lavendula angustifolia. The Journal of Alternative and Complementary Medicine, 14(8), 947-956.