New York Presbyterian Hospital/Columbia University Medical Center Family Medicine Residency Program, New York City (Drs. Shah, Killeen, and Meninno, and Shoshana Shine); Neighborhood Health, Alexandria, VA (Dr. Killeen) pas2176@cumc.columbia.edu
The authors reported no potential conflict of interest relevant to this article.
Like other dietary supplements, EOs are not regulated. No US regulatory agencies (eg, the US Food and Drug Administration [FDA] or Department of Agriculture [USDA]) certify or approve EOs for quality and purity. Bottles labeled with “QAI” for Quality Assurance International or “USDA Organic” will ensure the plant constituents used in the EO are from organic farming but do not attest to quality or purity.
Essential oils are one of the nonpharmacologic modalities that patients and clinicians have at their disposal for adjunctive treatment of migraine and tension-type headaches.
Manufacturers commonly use marketing terms such as “therapeutic grade” or “pure” to sell products, but again, these terms do not reflect the product’s quality or purity. A labeled single EO may contain contaminants, alcohol, or additional ingredients.7 When choosing to use EOs, identifying reputable brands is essential; one resource is the independent testing organization ConsumerLab.com.
It is important to assess the manufacturer and read ingredient labels before purchasing an EO to understand what the product contains. Reputable companies will identify the plant ingredient, usually by the formal Latin binomial name, and explain the extraction process. A more certain way to assess the quality and purity of an EO is to ask the manufacturer to provide a certificate of analysis and gas chromatography/mass spectroscopy (GC/MS) data for the specific product. Some manufacturers offer GC/MS test results on their website Quality page.8 Others have detailed information on quality and testing, and GC/MS test reports can be obtained.9 Yet another manufacturer has test results on a product page matching reports to batch codes.10
Which conditions have evidence of benefit from essential oils?
EOs currently are being studied for treatment of many conditions—including pain, GI disorders, behavioral health disorders, and women’s health issues. The TABLE summarizes the conditions treated, outcomes, and practical applications of EOs.11-44
Pain
Headache. As an adjunct to available medications and procedures for headache treatment, EOs are one of the nonpharmacologic modalities that patients and clinicians have at their disposal for both migraine and tension-type headaches. A systematic review of 19 randomized controlled trials (RCTs) examining the effects of herbal ingredients for the acute treatment or prophylaxis of migraines found certain topically applied or inhaled EOs, such as peppermint and chamomile, to be effective for migraine pain alleviation; however, topically applied rose oil was not effective.11-13 Note: “topical application” in these studies implies application of the EO to ≥ 1 of the following areas: temples, forehead, behind ears, or above upper lip/below the nose.
