Lavender oil is an essential oil obtained by distillation from the flower spikes of certain species of lavender. Two forms are distinguished, lavender flower oil, a colorless oil, insoluble in water, having a density of 0.885 g/mL; and lavender spike oil, a distillate from the herb Lavandula latifolia, having density 0.905 g/mL. Lavender flower oil is a designation of the National Formulary and the British Pharmacopoeia. Like all essential oils, it is not a pure compound; it is a complex mixture of naturally occurring phytochemicals, including linalool and linalyl acetate. Kashmir Lavender oil is famous for being produced from lavender at the foothills of the Himalayas. As of 2011, the biggest lavender oil producer in the world is Bulgaria.
Therapeutic uses 
Lavender oil, which has long been used in the production of perfume, can also be used in aromatherapy. The scent has a calming effect which may aid in relaxation and the reduction of anxiety and stress. Lasea capsules containing lavender oil with a high amount of linalool and linalyl acetate, termed Silexan by the manufacturer, are approved as an anxiolytic in Germany. The approval is based on a finding that the capsules are comparable in effect to low-dose lorazepam.
It may also help to relieve pain from tension headache when breathed in as vapor or diluted and rubbed on the skin. When added to a vaporizer, lavender oil may aid in the treatment of cough and respiratory infection.
Use in Alternative Medicine 
It is also said to treat a variety of common ailments, such as sunburn and sunstroke. It can also be used in massage oil mixtures, which may be effective in the relief of joint and muscle pain, or in chest rub mixtures for the relief of asthmatic and bronchitic spasm. It is also said to treat head lice when used in a hair rinse mixture, or on a fine comb to eliminate nits.One study suggests application of lavender essential oil instead of povidone-iodine for episiotomy wound care.
In vitro, lavender oil is cytotoxic as well as photosensitizing. A study demonstrated that lavender oil is cytotoxic to human skin cells in vitro (endothelial cells and fibroblasts) at a concentration of 0.25%. Linalool, a component of lavender oil, reflected the activity of the whole oil, indicating that linalool may be the active component of lavender oil. The result of another study showed that aqueous extracts reduced mitotic index, but induced chromosome aberrations and mitotic aberrations in comparison with control, significantly. Aqueous extracts induced breaks, stickiness, pole deviations and micronuclei. Furthermore, these effects were related to extract concentrations.
However, according to a 2005 study "although it was recently reported that lavender oil, and its major constituent linalyl acetate, are toxic to human skin cells in vitro, contact dermatitis to lavender oil appears to occur at only a very low frequency. The relevance of this in vitro toxicity to dermatological application of Lavandula oils remains unclear."
In terms of phototoxicity, a 2007 investigative report from European researchers stated that, "Lavender oil and sandalwood oil did not induce photohaemolysis in our test system. However, a few reports on photosensitivity reactions due to these substances have been published, e.g. one patient with persistent light reaction and a positive photo-patch test to sandalwood oil."
Other uses 
Oil of spike lavender has also occasionally been used as a solvent in oil painting, mainly before the use of distilled turpentine became common. For instance Francisco Pacheco mentions the use of lavender oil in his book "Arte de la pintura" (1649).
Lavender oil was implicated in gynecomastia, the abnormal development of breasts in young boys. Denver endocrinologist Clifford Bloch hypothesized the link after three boys presented with enlarged breasts. Subsequently, Derek Henley and Kenneth Korach of the National Institute of Environmental Health Sciences in Research Triangle Park, N.C., discovered in lavender and tea tree oil the presence of compounds which both suppress male hormones and mimic female hormones.
Because sex hormone levels normally are low prior to puberty, young boys and girls particularly are sensitive to estrogenic and androgenic compounds. The discovery of the gynecomastia link in boys has led some researchers to suspect lavender and tea tree oils, which are present in various personal care products including shampoos and lotions, may also contribute to the increased incidence of early breast development in girls.
The conclusion that the gynecomastia actually was caused by the essential oils in the products used by the three boys is disputed by the Natural Artisan Perfumers Guild and Cropwatch on the claimed basis of insufficient evidence. Work testing lavender oil using the model regarded as the gold-standard in vivo test for estrogenic activity "gave no evidence of estrogenic activity".
The conclusion that gynecomastia was caused by lavender has recently been disproven by research undertaken by Valerie T. Politano et al, Research Institute for Fragrance Materials and published in the International Journal of Toxicology.  Based on the data from the study, lavender oil, at dosages of 20 or 100 mg/kg, was not active in the rat uterotrophic assay and gave no evidence of estrogenic activity that could lead to gynecomastia.
The primary components of lavender oil are linalool (51%) and linalyl acetate (35%). Other components include α-pinene, limonene, 1,8-cineole, cis- and trans-ocimene, 3-octanone, camphor, caryophyllene, terpinen-4-ol and lavendulyl acetate. The composition of lavender essential oil as obtained by chromotography:
|Linalool||28.92 %||49.47 %|
- Bulgarian lavender producers worried about demand drop, China Post, 14 July 2011
- Shiina Y, Funabashi N, Lee K, Toyoda T, Sekine T, Honjo S, Hasegawa R, Kawata T, Wakatsuki Y, Hayashi S, Murakami S, Koike K, Daimon M, Komuro I.,"Relaxation effects of lavender aromatherapy improve coronary flow velocity reserve in healthy men evaluated by transthoracic Doppler echocardiography." Int J Cardiol. 2008 Sep 26;129(2):193-7
- Hongratanaworakit T.,"Aroma-therapeutic effects of massage blended essential oils on humans". Nat Prod Commun. 2011 Aug;6(8):1199-204
- Hwang JH.,"The effects of the inhalation method using essential oils on blood pressure and stress responses of clients with essential hypertension"Taehan Kanho Hakhoe Chi. 2006 Dec;36(7):1123-34
- "Über sieben Millionen Deutsche haben Angst" (in German). Presseportal. Retrieved 19 November 2010.
- Woelk, H.; Schläfke, S. (2010). "A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder". Phytomedicine 17 (2): 94–99. doi:10.1016/j.phymed.2009.10.006. PMID 19962288.
- Habanananda T.,"Non-pharmacological pain relief in labour." J Med Assoc Thai. 2004 Oct;87 Suppl 3:S194-202
- August 2006 issue of Dr. Alexander Grant’s Health Gazette.
- Vakilian K, Atarha M, Bekhradi R, Chaman R.,"Healing advantages of lavender essential oil during episiotomy recovery: a clinical trial." Complement Ther Clin Pract. 2011 Feb;17(1):50-3
- "Cytotoxicity of lavender oil and its major components to human skin cells" Prashar A, Locke IC, Evans CS
- "Cytotoxic and genotoxic effects of Lavandula stoechas aqueous extracts" Celik TA (Celik, Tulay Askin), Aslanturk OS (Aslanturk, Ozlem Sultan)
- Cavanagh H, Wilkinson J. Lavender essential oil: a review. Australian Infection Council, March 2005, Vol 10 Issue 1. http://www.publish.csiro.au/?act=view_file&file_id=HI05035.pdf
- Placzek M, Frömel W, Eberlein B, Gilbertz K-P, Przybilla B. Evaluation of Phototoxic Properties of Fragrances. Acta Dermato-Venereologica 2007: ISSN 0001-5555 doi:10.2340/00015555-0251
- See the article in the July 1, 2006 issue of Science News for further information on this study.
- Henley, DJ et al. N Engl J Med. 2007; 356: 479-485.
- A. Prashar, I. C. Locke, C. S. Evans (2004). Cytotoxicity of lavender oil and its major components to human skin cells. Cell Proliferation 37 (3), 221–229.