What's the deal with essential oils?

So what are essential oils anyway?

Essential oils are a concentrated extraction of the volatile oils from plants.

These oils are considered "volatile" because they evaporate easily at normal temperatures. The term “essential oil” is technically a misnomer because chemically speaking, they are actually a complex mixture of alcohols, terpenes, phenols, esters, and ketones, rather than an actual “oil”.

They are referred to commonly as an oil simply because they tend to behave as an oil. They have a low solubility in water, and will float on the surface past about a 4% dilution.

Hydrosols have about a 4% essential oils content, if more is added it will begin to accumulate on the surface.

The plant produces these oils to attract pollinators, repel predators, kill invading bacteria and fungus, or to block the intense sun by releasing a cloud of essential oils around the plant during the hottest portions of the day. Depending on the plant, the purpose can vary greatly.

Essential oils are about 75-100X more powerful than dried herbs. On average 1 oz (30 g) of plant will yield 1 drop of essential oil. In some cases such as roses, it takes roughly 60 000 roses to produce 30 ml of essential oil! This explains the higher cost of some oils compared to others. Some plants like lavender produce a lot more essential oil per plant and are therefore much cheaper to purchase. 



Humans have been using aromatic plants for thousands of years. Ancient application was mainly ritualistic in various religions, as well as to arouse sexual desire, and to generally improve quality of life. For example, the ancient Egyptians were well versed in the use of aromatic plants, and it was adopted as a way of life for them. The Perfumes, medicines, and  spices for cooking were common practice. Some of the rarer aromas like cinnamon and clove were highly regarded and reserved for only the most noble.

Many oils were used in the embalming process for treating dead royalty as well. They were thought to be the incense of the Gods. The smoke was used to attract good influences and repel evil.

 (Hofacker, 2016)

(Hofacker, 2016)

Alchemists in the middle ages made good use of essential oils from plants through sophisticated distillation processes to extract the "life essences” of plants. These distillation practices are what have led to the modern day techniques of extraction.

When essential oils in the form of aromatherapy came to Europe, they were used primarily in perfumes, but also in medicine. By 1190, the use of essential oils in perfume-making was so advanced, that King Philip Augustus developed guidelines requiring perfumers to train for 4 years and be tried by a jury before exercising their skills. They took it very seriously. The Renaissance saw a surge in herbology and expanded the use of essential oils to cosmetics. 

It was noticed during times of plague, that herb growers and perfumers were surviving the plague at a higher rate than the rest of the population. This was thought to be due to the antibiotic effects of many of the aromatic volatile oils.

Not everybody supported the use of aromatics however. In 1760, King George III of England proclaimed that women who seduced men through the use of scent could be thrown in jail for sorcery.


Whats Happening With Them Today?

Today, aromatherapy is widely used in massage therapy, skin care, psychology, hypnotherapy, and by chiropractors, herbalists, as well as home treatment. It is a recognized practice by many naturopaths in Canada, America, and Australia. Though North America is still lagging behind Europe in the use, research, and development of essential oils. Suppliers and users are growing rapidly however, and it is likely that it will one day become a part of mainstream medicine once again as the chemistry is analysed and tested further. 

 (Johnson, 2014)

(Johnson, 2014)

How Do They Work?

It is well documented that our sense of smell is over 10 000 times more sensitive than some of our other senses [1]. These oils produce effects through what is called the limbic system (referred to as the smell or primal brain). This system is one of the most ancient parts of our brains, remaining unchanged for over 20 000 years in human evolution.  It drives such things as hunger, sexual attraction, the endocrine system, the autonomic nervous system, emotions, and plays a role in memory.

There are also physical actions through ingestion, or topical application of essential oils. The volatile oils contained in plants are extremely complex and produce a wide range of actions.

 Photo credit: Noli, C. (2015)

Photo credit: Noli, C. (2015)


Though essential oils can be a great tool medicinally, and a positive influence emotionally, some precautions must be noted. Since essential oils are so highly concentrated, using large amounts at one time can be hazardous. Cinnamon for example can burn the skin when in high concentrations. These simple precautions must be considered when using essential oils:

  1. When using essential oils in the bathtub avoid getting vapours or bath water in your eyes.
  2. All essential oils must be kept away from children.
  3. Some essential oils such as thyme or eucalyptus must be used in small concentrations (3-4 drops). Know what the dangers are of the oils you are using or simply use less dangerous ones.
  4. If too much oil is applied or some has gotten into the eye, use an oil to remove, NOT WATER!! The essential oils are all soluble in oil and repelled by water. If you try to wash away essential oils with water it will just make the situation worse. Use vegetable oil and wipe it off with a cloth, this will dilute the concentration of the essential oils, and is the most effective home treatment.
  5. In general, it is best to use essential oils in low concentrations, which can be achieved by using only a few drops at a time (1-4), or by diluting into a carrier oil such as coconut or sweet almond oil, before using it on your skin.

Justin Cooke @JuzzieCooke

The Sunlight Experiment @TheSunlightExp


  1. BBC. (2014, September). BBC Science & Nature - Human Body and Mind - Nervous System Layer. Retrieved from http://www.bbc.co.uk/science/humanbody/body/factfiles/smell/smell_animation.shtml
  2. Hofacker, B. (2016). Raw Organic Cardamom Pods Ready to Use [Photograph]. Retrieved from https://www.flickr.com/photos/97092379@N04/24337312623/
  3. Johnson, K. (2014). Glass medicine vial and spoon on white background [Photograph]. Retrieved from https://www.flickr.com/photos/44509107@N03/23707363353/
  4. Noli, C. (2015). minimal food photography clara noli UK Italy [Photograph]. Retrieved from https://www.flickr.com/photos/124753421@N07/23655265469/
  5. Reling, C. (2015). Dried lavender herb and essential aromatherapy oil [photograph]. Retrieved from https://www.flickr.com/photos/132609512@N05/21097391573/