What is an Essential Oil

I sometimes get a blank stare when I tell people that I create blends, clean and heal various injuries using essential oils. Many nod their heads and know the term essential oil, but a sentence or two into the conversation, it is clear most do not understand what they are.

What most people know about essential oils – They smell good. That is a great place to start, For something considered so simple, I do not have a quick answer (when do I ever?). I was able to narrow it down to a few key points though.

Essential oils are highly concentrated volatile chemical compounds found in various plant parts. Each essential oil is unique. They are not found in every plant, but hundreds of essential oils have been found in plants around the globe. Small sacs of essential oil are undetectable to the naked eye and are found in all types of plant material (each plant is different) including leaves, flowers, grasses, roots, rhizomes, resins and trunks.

Essential oils are not really oils. While they are not water soluble (hydrophobic), they do not have fatty acids so they are not like the vegetable or plant oils that we consider oil. If rubbed between the fingers, they will not feel slick or ‘oily’ Note-essential oils safety is a topic for another post, but I do not recommend putting essential oils directly on the skin unless they have first been diluted in a carrier oil, lotion or body butter.

At a molecular level, essential oils are tiny (see picture below). A plants distinct aroma comes from the essential oils found within the plant. Each essential oil has its own unique composition of molecules and chemical components.

Magnified photo of leaf surface taken from Secretory Structures of Aromatic and Medicinal Plants, by Svoboda & Syred, 2000.

When these small sacs are broken the aroma is released. TRY IT – the next time you are holding an herb, rub it between your fingers and smell. Even better, if you have access to a lavender field, run your hands over the plants as you walk through and take note of how the aroma intensifies.

Basil is a common herb to have around the house

Essential oils are described in Gabriel Mojay’s book Aromatherapy for Healing the Spirit as “…the unique combination of the plant’s chemical constituents that determine both its synergy of therapeutic effects and its aroma. These can not be imitated by a chemical mixture that is produced in the laboratory.”

The chemical structure and components of an essential oil dictate its therapeutic effects (antibacterial, antiseptic, analgesic, etc.). Essential oils were used first and foremost by the plants that created them to protect the plant from pests, other invasive plants, disease, fungi, to heal it and/or to attract pollinators. Not surprising that after extracting them (usually using steam distillation), these same therapeutic or healing effects can be used by humans.

Recently, essential oils and aromatherapy have been getting a lot of attention.  Many are wondering if there is validity to the therapeutic claims or if it is a marketing ploy to capitalize on the swing toward ‘green’ and ‘sustainability.’ I think it is important to understand some of the basics. Knowledge is a powerful thing and at a minimum helps you be a wiser consumer.

Feel free to send any questions my way. Happy to point you to other resources to answer your question(s).



Davis, Patricia. Aromatherapy an A-Z. 3rd. London, UK: Vermilion, 2005. Print.

Keville, Kathi, and Mindy Green. Aromatherapy: A Complete Guide to the Healing Art. 2nd ed. New York, NY: Random House, 2009. Print.

Mojay, Gabriel. Aromatherapy for Healing the Spirit: Restoring Emotional and Mental Balance with Essential Oils. Rochester, VT: Healing Arts Press, 1999. Print.

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