Essential oils: How safe? How effective?

The cost varies enormously by manufacturer and type of plant used to make the EO. Common EOs such as peppermint and lavender oil generally cost $10 to $25, while rarer plant oils can cost $80 or more per bottle.

How safe are essential oils?

Patients may assume EOs are harmless because they are derived from natural plants and have been used medicinally for centuries. However, care must be taken with their use.

The safest way to use EOs is topically, although due to their highly concentrated nature, EOs should be diluted in an unscented neutral carrier oil such as coconut, jojoba, olive, or sweet almond.³ Ingestion of certain oils can cause hepatotoxicity, seizures, and even death.³ In fact, patients should speak with a knowledgeable physician before purchasing any oral EO capsules.

Whether used topically or ingested, all EOs carry risk for skin irritation and allergic reactions, and oral ingestion may result in some negative gastrointestinal (GI) adverse effects.⁴ A case report of 3 patients published in 2007 identified the potential for lavender and tea tree EOs to be endocrine disruptors.⁵

Inhalation of EOs may be harmful, as they emit many volatile organic compounds, some of which are considered potentially hazardous.⁶ At this time, there is insufficient evidence regarding inhaled EOs and their direct connection to respiratory health. It is reasonable to suggest, however, that the prolonged use of EOs and their use by patients who have lung conditions such as asthma or COPD should be avoided.⁷

Continue to: How are quality and purity assessed?