What Do We Smell in Eucalyptus Oils?

The essential oil of Eucalyptus leaves is breath-opening and medicinal, at once enlivening our senses and a defense of our immune system. What we smell of Eucalyptus essential oils are scent molecules, extracted from the fresh leaves by steam-distillation.

A substance with decongesting actions called cineole is really prominent in Eucalyptus essential oils. There are other substances, such as pinene and limonene and globulol, that are so pleasant to breathe when we have inflammation or pain; they reduce excitability, discourage coughing, influence the production of oil in the skin, and more.

In writing about the scents of Eucalyptus trees, I recall the airy, dry shade that felt so welcoming on a hot day in Southern California. Under their canopy, constantly falling strips of bark and leaves fluttering to the ground allowed me to touch and savor fresh Eualyptus scent in real time. If I stood close to the tree trunk, I’d be enveloped by their resolute, resilient presence, their elegantly curved leaves and fascinating flower bud capsules.

The remembered aromas of leaves and buds increases my experience even now, on inhaling their essential oils.

Layers of Scent in Eucalyptus & Our First Impressions

It’s said that “beauty is in the eyes of the beholder”. But what about the aroma of leaves? When inhaling Eucalyptus oil, what you and I smell are the layers of scent. Can we easily detect cineole, for example, or peppermint or lemon scent in an oil? Wanting to share my impessions with you, how would I describe them? But how the scent is meaningful if indeed it is, is unique to each of us.

Taking into account the layers of scent and our reactions to them makes your interlude with this essential oil** a meaningful experience.

Scent of Eucalyptus

Intense aromas from leaves are a positive sensation for the lungs. I find that I love Eucalyptus for its bright, sweet, and balsamic aromas. Here’s a look at the aromatic layers of Eucalyptus globulus and Eucalyptus radiata, two of the strongest oils for respiratory support.

First of all, some Eucalyptus oils are described as “camphoraceous”. That means its aroma is like camphor, one of the most intense, but pleasant, scents from plants.

Intense Aroma of Camphor

More than 230 years ago, Eucalyptus trees were identified as producing a substitute for camphor, a medicinal substance then known world-wide, but which was not easily obstained.

It turned out that not all Eucalyptus leaves offer the same aroma. Between 600-700 different kinds or species of Eucalyptus are known, grown in Australia, Spain, Portugal, Brazil, South Africa, and China.

“Camphoraceous” or “camphor-like”, is a word used to describe the substance cineole. A product of Blue Gum Eucalyptus (Eucalyptus globulus) leaves, cineole is found in the Blue Leaved Mallee (E. polybractea), Narrow-leaved Eucalyptus (E. radiata), and Broad-leaved Peppermint (E. dives). And other Eucalyptus, Green Mallee (E.viridis) and Lemon-scented Ironbark (E. stageriana) offer cineole, too, (also called eucalyptol) with citrus scent being more dominant.

Of course all Eucalyptus chemical subtances are mixtures of essences that are anti-bacterial and anti-inflammatory. More calming are the citrus or lemon-scented Eucalyptus types. Narrow-leaf offers an antidote to colds, viruses, immunity, and calms the nerves. Blue Gum offers the strongest expectorant and anti-mucus actions. Broad-leaf peppermint’s healing actions extend from the lungs to assist detoxification.

Infection Protection

The main substance in Eucalyptus tree leaves is cineole. Cineole is what makes Eucalyptus oils a famous remedy for colds, flus, and infections. As a substance, cineole is also called eucalyptol, and is found in a variety of plant oils. A healing substance, 1,8 cineole has medicinal action for the respiratory system and excess mucus. The leaves of the Blue Gum Eucalyptus have this substance in abundance. The genus Eucalyptus (the word “genus” is the botanical category for plant groupings with similar physical features) produces the eucalyptol scent, which is also smelled in other eucalypts, even if they’re known as peppermint and lemon-scented eucalyptus, etc.

Cineole, the substance, is properly called 1,8 cineole. It is also present in leaf oils of Rosemary ct. cineole, Bay Laurel, and Tea Tree, among others. Blending Eucalyptus with one or more of these results in a synergy, or blend of compatible aromatic molecules.

Eucalyptus Curiosities

Two curiosities about the scent of Eucalyptus leaves seem appropriate to this post. They are both culturally-based, one Western, one Eastern in origin.

In her book The Scent Trail, Celia Lyttelton briefly outlines aromatherapy in history. She recounts ancient and more modern people’s discovery of aromas and healing. According to Lyttleton, in 17th century England, Eucalyptus oil was balm for anything disturbing the brain. At that time, the concept of the brain might have included not only our thoughts and mental abilities but also our upper respiratory functions, like breathing and our sense of smell. Any thing “disturbing the brain” seems appropriate now since Eucalyptus leaves are thought to contain substances that awaken the brain or increase alertness.

Another account of the meaning of scent is found with Chinese herbal medicine and is not specific to one herb. It’s mentioned by author Mailhebiau in his Portraits in Oils, c1995. He points out that the patient’s first contact with herbs is when they are being prepared as medicine, usually as a tea. When making tea herbs are steeped in hot water, releasing their scent in the process, and opening the healing pathway. This is known as the medicine of scent!

You might be wondering how this could be important. Well, it turns out that inhaling an aroma is not an accidental benefit, but is part of the healing objective! The Chinese believe that healing comes from both parts of our sensory apparatus: both taste and smell. They intend for “taste to act on the internal structures” — paraphrased from p. 33, Portraits in Oils.

Please note:

Do Not Use Essential Oils Internally.

Please do not use Eucalyptus essential oil, or blends containing it, or those with cineole components, with children less than 10 years of age. Younger children’s respiratory systems are not strong enough to inhale and parse the volatile aromas in this resinous oil. Read an article on cautions when using this substance, by Jade Shutes. Jade Shutes, aromatherapist, author, teacher, founder of The School for Aromatic Studies, writes extensively on the qualities and uses of essential oils.

So, what do we smell in Eucalyptus essential oil?

Common names seem to stick, especially to essences that come from exotic places, that were traded in ancient times, but brought to Europe more recently. One of these common names is ‘peppermint tree’, assigned to Narrow-leaf Eucalyptus (Eucalyptus radiata). In technical terms, or not, what we smell are three layers of aromatic essences, one of which is not necessarily peppermint! Components of Eucalptus Blue Gum and Narrow-leaf are the medicinal aromas of cineole, plus a pine-like scent and a component, limonene, which is found in citrus oils and other essential oils. It has a soothing property.

Other Myrtle family scents are powerful, too.

Eucalyptus is part of the Myrtle family of plants. Besides Eucalyptus, Myrtle family scents include Niaouli, another cineole-prominent oil for the respiratory system.

Ravintsara (Cinnamomum camphora—from Madagascar) or Niaouli (Melaleuca quinquenervia—from the east coast of Australia, Caledonia and New Guinea) can be blended with Eucalyptus Blue Gum (or Narrow-leaved Eucalyptus) for respiratory complaints. Other oils are Peppermint, Thyme, Cajeput and Rosemary which extend the medicinal actions, or open the breath and this stimulates the mind.

Blend with Blue Gum or Narrow-leaf Eucalyptus Essential Oil

One of the best (and my favorite) ways to explore an essential oil is for their emotional benefits. Because a lot of the times, we may not realize that the sensations of discomfort in the body come from emotional stress. Especially since stress can make us feel trapped and suffocated.

A beautiful combination or blend for effortless flow and positive feeling can be made with Eucalyptus paired with a fruit or berry essential oil. Try this combination for emotional freedom and uplift.

Eucalyptus-Juniperberry with Green Mandarin

3 drops Eucalyptus (E. radiata) essential oil
3 drops Juniperberry (Juniperus communis) essential oil
3 drops Green Mandarin (Citrus reticulata) essential oil
2 drops Cistus (Cistus ladaniferus) essential oil

About 10ml Jojoba oil (Simmondsia chinensis) to fill a 10ml glass bottle with roll-on top and cap.

Method: drop essential oils into the roll-on bottle, drop by drop. Close cap and swirl to combine the blend. Allow to rest overnight. Next day, open the cap and pour in Jojoba oil to reach the neck of the bottle. Apply the roller top tightly. Re-cap tightly and swirl the bottle once more to thoroughly blend. Ready to use!

SAFETY NOTE: Be Safe! when using essential oils and products of natural origin. Always dilute essential oils in a carrier oil before applying to the face or body, or when adding to bath water. Ask your aromatherapist or herbalist for guidance.

Ask your health care provider before using essential oils in pregnancy, or when trying to become pregnant, OR taking medication for any condition. Do not use essential oils internally.

This post is for informational purposes only and is not intended as medical treatment for any disease or condition. Do not use Eucalyptus oils with or around children under 10 years of age.

You may contact me, here to comment or ask questions.