What You Need to Unlearn About Essential Oil Chemistry

What You Need to Unlearn About Essential Oil Chemistry

“We’ve got to clear this up right here.”

We knew she was getting serious.

After a day and a half of classes, the joking and feel-good fun aside, she was about to tell us something really important.

“I’ve got to debunk this Functional Group Theory myth …”

Sylla explained the basic idea of Functional Group Theory, which is that you can tell the action of a chemical constituent based on its structure. Then she told us why we need to take that with a grain of salt.

To a budding aromatherapist who didn’t have much of an understanding of the chemistry to begin with … the idea of debunking something that I didn’t have a grasp of yet was hard to wrap my brain around.

But now that I’ve been in the aromatherapy field for almost a decade, I see what she was saying.

Sylla was referring to statements heard throughout the world of aromatherapy education:

“Monoterpenes are ‘stimulating’ and ‘detoxifying.’” (Don’t even get Sylla started on that.)

“Ketones are toxic.”

“Esters make you feel good.”

These are great conventions to begin with—to have a conceptual framework for the chemistry of aromatics.

But at some point, you need to realize that the world of chemistry is more complicated than, “These things that look the same … act the same.”

I mean, jeez, imagine if I said that about a group of people. Chemistry, like people, is more complex than that.

Just because constituents have similar structures that we can identify doesn’t mean they are going to have the same action.

Since the 1990’s, Mom’s been saying that we as an industry need to take a look at this assumption. She used to be the only one (that I knew of ) talking about it.

I don’t know how many times I’ve heard her say, “We can’t say, ‘All ketones do this,’ or ‘All sesquiterpenes do that.’” I’m glad to see this coming to light now.

This has always been a subject of discussion in our Aromatherapy Practitioner Course. Those of you who are already our students can turn to page 179 to find more information. If you’re not a student and want to learn this multi-dimensional approach to aromatherapy, contact us to get started.  

Though it can seem like splitting hairs, the truth is this: if you’re going to study aromatherapy, you want to know how deep you’re willing to go. You might wear the floaties in the beginning, but eventually you need to be able to swim on your own if you’re going to understand the chemistry beyond this oversimplification.

Sure, maybe not every home-user needs to know the difference between thujone and verbenone, or why phenolic compounds are irritants. But we also need to not base generalizations on things that are … well, just generalizations.

Here’s what Sylla has to say:

We may need to learn what this Functional Group Theory is all about in order to unlearn what we may have thought.

Here are some resources for more information:

We wanted to write about this because it came up in our Blue Tansy Deep Dive that is in the Atlantic Aromatic Library. If you’re interested in going deeper with your study of essential oils, this lifetime access to the Library is for you.

Now, we’d like to know:

How does this insight change your view on essential oil chemistry? What is one thing you can do moving forward to nurture a deeper understanding of essential oils?

Let us know by leaving a comment below!


How to Fall In Love with Essential Oil Chemistry

How to Fall In Love with Essential Oil Chemistry

Are you struggling to understand essential oil chemistry?

Do monoterpenes and aldehydes go bump in the night, sending you into flashbacks of the classes you hated in high school? (They did for me!)

Do you yearn to speak of esters and phenols with fondness, the way some aroma-nerds do?

I previously had an experienced aromatherapy teacher ask me for advice on teaching essential oil chemistry. This person has been studying essential oils since before I graduated from high school, but they still find it difficult to teach something that many students find hard to grasp.

Chemistry Can Be Fun

Chemistry is one of those subjects, which for so many, fear takes their curiosity hostage. But no more, aroma friends!

The truth is, chemistry can be enlightening, empowering, and (even) fun. Today’s interview shows you how.

I recently sat down with my friend and colleague, Dr. Timothy Miller. Tim is a naturopathic physician, licensed acupuncturist, and registered aromatherapist whose passion is in teaching. In this arena, he wears his heart on his sleeve—making his love for aromatic chemistry known far and wide. But not only that, he also wants to spark that love in all of us.

In this interview, you’ll learn:

  • How the love of chemistry (and the teaching of it) started for Dr. Tim.
  • What the biggest blocks are when studying chemistry—and how to break through them.
  • How aromatherapy sometimes gets chemistry wrong (or just not-quite-right).
  • How to study essential oil chemistry at home.
  • What makes trans-anethole unlike any other component.


We hope this interview can help clear up some misconceptions and allow you to approach chemistry in a new light. Once we start embracing this molecular science, we can enjoy a deeper understanding of the aromatic materials we’re working with. It can make us better students, better teachers, and better aromatherapists.

Did something in this interview spark a love for chemistry in your heart?

Leave us a comment and let us know what you learned. What fascinates you about essential oil chemistry? In what ways could essential oil chemistry still woo your heart? What larger questions do you still need answered?

Thank you for sharing in the love of chemistry and essential oils with us. We are grateful, as always, to be a part of your journey in aromatherapy.

Aromatically Yours,




Learn AromaChemistry with Dr. Tim

aromachemistry poem

Do you want more chemistry with Dr. Tim?  Learn more about his AromaChemistry online course here.

Want to learn more about aromatherapy, essential oils, and their chemistry with us? Check out the Atlantic Aromatic Library and our other course offerings.