They’re often mentioned in the same breath as new-agey trends like crystal healing (a practice with lots of wellness cool cred but little scientific proof), but essential oils are actually backed by decades of research. We turned to Kurt Schnaubelt, Ph.D., a world-renowned aromatherapist and author of The Healing Intelligence of Essential Oils (also: the expert behind our Aromatherapy Collection), to help illuminate aromatherapy—a science that very much feels like magic.  

Q: What led you—a scientist— to study essential oils in the first place?
A: I was writing my doctoral thesis in chemistry at The Technical University of Munich, and discovered this book by Robert Tisserand called The Art of AromatherapyI remember thinking: well, what a bunch of hogwash! But it piqued my interest, so I read the book, started looking into the research, and found out that one of the field’s leading experts, Hildebert Wagner, was actually at the other university in Munich, Ludwig Maximilian University. His research still makes up much of the foundation of what we know about essential oils and aromatherapy in scientific terms. This coincidence sparked something in me, and I dug deeper and deeper into the research.

Q: What did the research show?
A: At that time—'70s, ‘80s, and ‘90s—what a lot of people did was demonstrate the cause and effect of essential oils. So, they'd take an essential oil and apply it any kind of test system: maybe you’d put an essential oil in a Petri dish and see that bacteria doesn’t grow anymore and then conclude that the oil is anti-infectious. These early studies gave us the first good insight into what essential oils do.

Q: Is it understood how exactly essential oils do this?
A: After this first wave of research came what’s known as French style aromatherapy, where studies tried to pin certain effects to certain types of compounds found in these essential oils. Every essential oil is made up of different compounds. Then, all of a sudden, we were able to connect an individual oil’s antiviral activity, for example, with its eucalyptol component. There was a scientific narrative that could explain how essential oils work. Currently, there is research occurring where they are documenting the effects that these compounds have in actual cells. This research is showing how these components of essential oils interact with specific molecular targets and receptors, which explains how essential oils work through various application types.

Q: There are so many essential oils on the market—what is the marker of a high-quality one?
A: The degree of authenticity—the more it represents the plant where it comes from, and the less it has been engineered. That's where you get the quality. A whole essential oil comes from the plant directly to you by distillation or cold-pressing.

Q: What does it mean if an essential oil has been engineered?
A: Well, there are certain things that will be necessary— like filtering if there are particles in it. But other than that, there's a whole gamut. It may just be that when you are a big company and you have a huge demand, you're trying to supply all your fans with geranium essential oil, for example. All of a sudden, you realize that the geranium that you get from this island in the Indian Ocean isn’t enough, so you start mixing it with the geranium from Egypt. Then you still have geranium essential oil—but it’s been concocted to some degree.

I think what happens a lot today is that the companies that go through large quantities of essential oils use what are called natural isolates to save money. Take neroli, which contains a certain percentage of the compound linalool. You can add a natural isolate of linalool, which is really inexpensive, to your neroli, and that stretches the supply of your very expensive neroli. And this linalool isolate could have been extracted from basil.

Q: Why does that matter?
A: When you use an oil from a plant, you use the oil from that plant because you want that effect from the plant. When you use neroli, you want the anti-anxiety effect of the neroli. If you add the basil in there, although it’s still natural, it's not neroli anymore—and it’s not a whole, authentic essential oil, it's 90 percent neroli and 10 percent basil.

Q: Where do you see aromatherapy having the biggest impact right now?
A: If you look at where aromatherapy is popular, it's in the industrialized urban areas of the world—and that makes sense because that's where people are missing out on these aromatic compounds from nature. I see this when I travel to give seminars. It's simply a missing element in the urban lifestyle. When you have an essential oil, you get some nature in a bottle.