What are lavender's therapeutic uses?

Overview

There are many plants in the lavender family, but the type most commonly used
medicinally is English lavender. Traditionally, the essential oil
of lavender was applied externally to treat joint pain, muscle aches, and a
variety of skin conditions, including insect stings, acne, eczema, and burns.
Lavender essential oil was also inhaled to relieve headaches, anxiety, and stress.
Tincture of lavender was taken by mouth for joint pain, depression, migraines,
indigestion, and anxiety. Lavender was additionally used as a hair rinse and as a
fragrance in “dream pillows” and potpourri.

Therapeutic Dosages

When used internally, lavender tincture is taken at a dose of 2 to 4 milliliters three times a day. Lavender essential oil is used externally or by inhalation only; it should not be used internally.

Therapeutic Uses

Lavender continues to be recommended for all its traditional uses. Only a few of these uses, however, have any supporting scientific evidence whatsoever, and for none of these is the evidence strong.

A few studies suggest that lavender oil, when taken by inhalation
(aromatherapy) might reduce agitation in people with severe
dementia. For example, in one well-designed but small study, a hospital ward was
suffused with either lavender oil or water for two hours. An investigator who was
unaware of the study’s design and who wore a device to block inhalation of odors
entered the ward and evaluated the behavior of the fifteen residents, all of whom
had dementia. The results indicated that the use of lavender oil aromatherapy
modestly decreased agitated behavior. A somewhat less rigorous study reported
similar benefits. Rigor is essential in such studies, as it has been shown that
merely creating expectations about the effects of aromas may be sufficient to
cause these effects.

A preliminary controlled trial found some evidence that lavender, administered through an oxygen face mask, reduced the need for pain medications following gastric banding surgery. A small study performed in Iran reported that oral use of lavender tincture augmented the effectiveness of a pharmaceutical treatment for depression. However, this study suffered from numerous problems, both in design and reporting, and in the scientific reputation of the investigators involved.

In a controlled trial with more than six hundred participants, lavender oil in bath water failed to improve perineal pain after childbirth. One poorly designed study found weak hints that lavender might be useful for insomnia. One animal study failed to find that lavender oil enhances wound healing. Lavender is also used in combination with other essential oils.

Safety Issues

No form of lavender has undergone comprehensive safety testing. Internal use of
lavender essential oil is unsafe and should be avoided. Topical use is considered
much safer. Allergic reactions are relatively common, as with all essential oils.
In addition, one case suggests that a combination of lavender oil and
tea
tree oil applied topically caused gynecomastia (male breast
enlargement) in three young boys.

A controlled study found that inhalation of lavender essential oil might impair some aspects of mental function. (Presumably, this was caused by the intended sedative effects of the treatment.) Oral use of tincture of lavender has not been associated with any severe adverse effects, but comprehensive safety testing has not been performed. Finally, the maximum safe doses of any form of lavender remain unknown for pregnant or nursing women, for young children, and for people with severe liver or kidney disease.

Bibliography

Akhondzadeh, S., et al. “Comparison of Lavandula angustifolia Mill. Tincture and Imipramine in the Treatment of Mild to Moderate Depression.” Progress in Neuro-Psychopharmacology and Biological Psychiatry 27 (2003): 123-127.

Henley, D. V., et al. “Prepubertal Gynecomastia Linked to Lavender and Tea Tree Oils.” New England Journal of Medicine 356 (2007): 479-485.

Kim, J. T., et al. “Treatment with Lavender Aromatherapy in the Post-Anesthesia Care Unit Reduces Opioid Requirements of Morbidly Obese Patients Undergoing Laparoscopic Adjustable Gastric Banding.” Obesity Surgery 17 (2007): 920-925.

Lewith, G. T., et al. “A Single-Blinded, Randomized Pilot Study Evaluating the Aroma of Lavandula augustifolia as a Treatment for Mild Insomnia.” Journal of Alternative and Complementary Medicine 11 (2005): 631-637.

Lusby, P. E., et al. “A Comparison of Wound Healing Following Treatment with Lavandula x allardii Honey or Essential Oil.” Phytotherapy Research 20, no. 9 (2006): 755-757.

Moss, M., et al. “Aromas of Rosemary and Lavender Essential Oils Differentially Affect Cognition and Mood in Healthy Adults.” International Journal of Neuroscience 113 (2003): 15-38.