Lavender oil
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. Lavender Flower Oil is a designation of the National Formulary and the British Pharmacopoeia. It is not a pure compound; it is a complex mixture of natural products. Lavender oil should never be taken internally.

# 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. 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.
Lavender oil may also be used as a mosquito repellent when worn as perfume or when added to lotions or hair products.

# Medicinal uses
According to advocates of alternative medicine, lavender oil can be used as first aid and to treat a variety of common ailments.
The diluted or undiluted oil may be used as an antiseptic and pain reliever to be applied to minor burns and insect bites and stings. For the treatment of sunburn and sunstroke, 10 drops of oil can be diluted in 25 mL of carrier oil. (Note: This is not an effective sunblock.) When added to chamomile, lavender oil may be effective on eczema.
To create a massage oil which may be effective in the relief of joint and muscle pain, 1 mL of oil can be added to 1 oz. of carrier oil and rubbed liberally on the affected area. To create a chest rub for relief of asthmatic and bronchitic spasm, 1 mL of lavender oil and 5 drops of chamomile oil can be added to 10 mL of carrier oil.
As a treatment for head lice, 5-10 drops of oil can be diluted in water to produce a hair rinse, while a few drops of undiluted oil can be added to a fine comb to eliminate nits.
As far as serious ailments, researchers at the University of Wisconsin-Madison have found that lavender oil may have played a role in the reduction of advanced mammary tumors in lab rats. Research is on-going for potential breast, ovarian, pancreatic, liver, and prostate cancer treatments.

# Contraindications
Lavender oil has recently been implicated in gynecomastia, the abnormal development of breasts in young boys. Denver endocrinologist Clifford Bloch discovered the link after several 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 are normally low prior to puberty, young boys and girls are particularly 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.
Discontinuation of use of these products resulted in rapid reversal of gynecomastia in Blochs young patients.
However, the conclusion that the gynecomastia was actually caused by the essential oils in these products are currently being disputed by the Artisan Perfumers Guild and Cropwatch due to insufficient evidence.

# Composition
The primary components of lavender oil are linalyl acetate (51%) and linalool (35%) . Other components include -pinene, limonene, 1,8-cineole, cis- and trans-ocimene, 3-octanone, camphor, caryophyllene, terpinen-4-ol and lavendulyl acetate .