Essential Oils Testing — Is it Reliable?


Essential Oils Testing  - Is It Reliable?  So many people talk about the GC/MS test to show whether and essential oil is pure or not.  But is it enough?  I talk about that and what other things you should be looking at when trying to figure out if an essential oils has good quality oils or not.

If you haven’t noticed, there has been a lot of hubbub on the internet about essential oils these days.  There are loads of blogs telling you that their oils company is the best one and my blog series about my search for the best essential oils company has been extremely popular.  Often, in posts about oils, you are urged to sign up with a direct sales company to makes money selling oils, or at least to get your oils for free.

There are essential oils remedies, recipes, “Medicine Cabinet Makeovers,” information about antibacterial essential oils,  and testimonials galore.

One thing that comes up over and over again regarding essential oils, however, is GC/MS testing.

Today we are going to talk about GC/MS testing in more detail.

We’ll learn:

What GC/MS testing is
What GC/MS tests tells us
What GC/MS testing’s limitations are

Stay with me–this is going to be very interesting.

What is GC/MS testing?

GC/MS testing is Gas chromatography–mass spectrometry.  

What does that mean, you ask?

Basically, here’s what a GC/MS test does:

1.  The essential oils are injected into an apparatus with a tube.  The tube is coated with material that has different affinities for different chemicals at different temperatures.

2.  The temperature of the apparatus is gradually increased.

3.  The oil vapors are moved through the apparatus to a detector at the end of the column.

4.  The detector responds to the vaporized parts of the oils by printing out proportional peaks on paper.

5.  The height of each peak corresponds to the amount of each component of the oil.

6.  Components are identified by the time at which the peak prints out on the paper.

7.  The data for each oil can be compared with standards, or “fingerprints,” for each essential oil to make determinations about purity and other qualities about the oil.

Complex, but pretty neat, huh?

Basically, you get data about what components are in the oils and how much of each component there is.

S0–does that mean that if a company does GC/MS testing, that you can buy their oils and be sure you are getting “the real deal“?

And does it mean the if a company’s GC/MS tests come out within industry standards that you should feel comfortable using them?


While GC/MS testing can tell us a lot, there are some problems with relying on these tests alone.

1.  Essential Oils Can Be Adulterated in Ways that GC/MS tests cannot determine.

a.  Adding synthetics: For example, if synthetic linalyl acetate is added to pure lavender oil, a GC-MS analysis cannot tell whether that compound is synthetic or natural, only that it is linalyl acetate.

b.  Heating: Some oils are heated to burn off more “herby” smells, as with Eucalyptus Globulus or Peppermint.

c.  Redistilling – Some oils are redistilled to make their fragrance more appealing.  I talked about this in this post.

d.  Blending of oils to Save Money or Get Uniform Smell
i. An “expert” might dilute a more expensive lavender with a less expensive lavender in order to sell the less expensive oil for a higher profit.

ii.  Sometimes customers complain that their oil “doesn’t smell like it did before.”  That can be a good thing, because oil smell should vary a bit–depending on weather, time of year, amount of water, etc.  However, sometimes oils are blended with other batches to avoid this kind of customer complaint.

I would rather have my oils vary in smell than have them mixed with other oils.

2.  The Standards for the GC/MS testing were set up more for the food, fragrance, and flavoring industries, rather than for therapeutic oils.

When using the standardized guides and GC/MS testing, there are ranges that components of the essential oils are supposed to fall between.

For example, terpinen-4-ol is the active ingredient in tea tree oil that is supposed to be the most therapeutic.  When tea tree oil undergoes GC/MS testing, the compliant range for terpinen-4-ol is between 30 and 48%, and the “compliant range” for terpineol is 1.5 – 8%.  So the compliant range for the two combined is 31.5 – 56%.

However, since terpinen-4-ol is the most desired healing component of tea tree oil, some distillers have figured out ways to distill tea tree oil in order to have the resulting oil have a greater percentage of terpinen-4-ol.  You can see an example of this here.

Main Camp Natural Extracts claims to be “the purest tea tree oil in the world.”  Now, I don’t know about “purest” but they do have some pretty strong tea tree oil.  Their terpinen-4-ol + terpineol is a minimum of 75% and it typically is over 80%.  That clearly is well outside of the GC/MS guidelines.

So Main Camp’s oil would not test compliant with GC/MS testing, but it seems to be a valuable tea tree oil, nonetheless.

Depending what you think about the method they used to extract more terpinen-4-ol, you may or may not want that oil, but this example just goes to show that having more of an active ingredient in an oil might make the oil more therapeutic without it testing “compliant” on a GC/MS test.

Sacred Frankincense is another oil where this is done.  Some distillers can apparently tweak the advanced tech extraction that will just extract greater proportions of the anti-cancer component in frankincense oil.  The resulting oil won’t test compliant with GC/MS testing, but it is technically “more therapeutic.”

3.  GC/MS testing does not determine soil quality.

GC/MS testing only tests volatile (those that evaporate rather quickly) chemicals.

Such testing can’t make allowance for whether or not a plant was grown in soil with quality nutritional components.

We all know that organic farming practices yield higher quality produce.  As such, one would expect that the same would hold true for essential oils–we would expect that essential oils grown in high quality soil would have more therapeutic benefits.

4.  GC/MS testing does not test for many environmental toxins.

Since GC/MS testing can only test for volatile chemicals, it won’t test for heavy metals or other toxins that are heavy.

What kinds of toxins won’t show up on a GC/MS test?  (I don’t want any of these in my oils–ick!)

a.  Trace amounts of iron from an iron distiller might break off and end up in the oil.

b.  Radiation

c.  Heavy Metals

d.  Heavier Pesticides

e.  Pollution components

f.  Heavier chemicals from fertilizers

There are lots of things that could be in essential oils that I know I don’t want on my body, because there are lots of oil-soluble chemicals, pesticides, etc.   Of course, you might think that a small amount of toxins might not be a big issue, but over time it can accumulate, especially if you are using the oils frequently.  And with our toxic environment, why add anything to the burden you and your family are already under?

Also you might be purchasing organically grown oils, but if the farm is next to a heavily-polluted area, the plants will likely be polluted.

Something to think about:  Would you want an essential oil that was grown on toxic waste that passes the GC/MS reference standards, or would you rather have an essential oil grown organically that does not meet the testing standards for some reason?

I know which one I would want ;-).


Remember back in my series about my path to choosing the essential oils company that my family was going to be using?

Along the way, I heard all kinds of things about testing and certifications, some of which the oils companies made up themselves.

Well, testing is important.

But so are a lot of other things.

Here are the things that I recommend you look for in an oil company:

Signs of a Quality Essential Oil Company

1.  Experience
2.  Purity
3.  Plants grown in indigenous locations
4.  Organic and/or wild-crafted when available
5.  Most plants are grown in remote locations where no pesticides, herbicides, or harmful chemicals are used and only natural fertilizers are used.
5.  Reasonable shipping prices
6.  Reasonable pricing
7.  No solvents used
8.  No artificial oils sold
9.  No adulterating (no heating, blending, adding or further distillation of oils)
10.  Sourced from Small Farms
11.  Common Sense Approach to oils – no “over-recommending” of internal use of oils and reasonable caution in overall use of oils.

There are so many essential oils companies to choose from that it can be hard to know where to go to buy quality essential oils.

{Please note that the links to Native American and Rocky Mountain Oils are affiliate links. If you click on them and make a purchase, I might make a commission. Your support is much appreciated and helps keep this free resource up and running.}

I personally have chosen Native American Nutritionals as the company that I buy my family’s essential oils from.  I trust them and they meet all of the above criteria and more.  I will be writing more about them in the near future.

Native American Nutritionals and Rocky Mountain Oils share the same quality oils but some of their offerings are different.  If you are a beginner, you might find the products at Rocky Mountain Oils to be a bit easier to sort through as Native American Nutritionals has more varieties of certain oils to choose from.

Regardless, you will be in good hands with either company.

Want More Information About Essential Oils?

Here’s a new guide that I just wrote – 10 Things You NEED to Know About Essential Oils BEFORE You Buy.

Additionally, I am not a medical practitioner.  This blog is for entertainment purposes and you should not make any changes to your diet, exercise, or natural health regiment without discussing with your physician first.**


What do you think?  Please share your comments below.

(The top image is the copyrighted property of 123rf limited.  They are a contributor or licensed partner and their image is being used with permission under license and cannot be copied or downloaded without permission from 123rf limited.)


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  1. Hello, I was wondering if you could suggest which oils you think would be good for children on the Autism Spectrum I’m ready to start using essential oils in my home and if safe on my son who has autism, if you could help me out between any of the two sites NAN or RMO I would grately appreciate any information

  2. Anxiety focus etc. And if possible something that could help with sleeping

    • Tranquility is supposed to be good for sleep. (affiliate link). For anxiety I would try Peace and Quiet (affiliate link), and for Focus I am personally buying Attention Assist (aff link) and Focusing (aff link). I can’t medically advise of course, but these would be the first I would go to.
      Plain old lavender is typically one folks like for sleep. (aff link)

      Those links are to Rocky Mountain Oils. They have an easier selection for those who aren’t advanced oil users and the oils are the same as Native American – just in case you are wondering. I think the site is a bit more user friendly. Take care!

      • Hi there, first of all thank you so much for all your hard work, time and energy in evaluating these Essential Oils. It’s been really helpful for me (being a newbie). I took your recommendation and have been ordering Native American Nutritionals and am happy so far! In case you didn’t know, NAN and Rocky Mountain Oils have merged. You probably know this but I just found out and wanted to share. Thank you so much for all you do for us!!! :)

        • Hi and thanks for commenting. I’m so glad you are liking them! Yes, they have been talking about his for awhile – they have more news coming out so stay tuned :) and you are so welcome.

  3. Hello,

    I did get Attention Assist and do not find any noticeable difference. Have you started using it? If yes, did you notice an improvement? I am also wondering how you’re using it if you are.
    Thanks for all of your time and research.


  4. Adrienne, thank you for all the time you have spent to share your EO journey. I became interested in using EOs about a year ago, and have started using them more seriously the last few months and have to say all the information and contradicting information can be overwhelming. I read the qualities you look for in a company, but was wondering if you have a list of questions a consumer should use to inquire about a company? If I ask about what distillation they use, where the plants are sourced etc. is that enough? If I ask “do you add anything to your oils” will I get a straight answer? I haven’t read through all the comments and know you’ve mentioned you can’t research every company but was wondering if you had any thoughts on Eden’s Garden? Lastly I’d just like to share a recent experience and lesson learned with one of the MLM companies. Seeking to learn more about using essential oils and clear up some of my confusion I was excited to attend a free class. To show us the potency of oils the “educator” put a drop of peppermint neat in all of our palms, told us to rub it with our thumb and tap our thumb on the rough of our mouth, then breath deeply from our palm. I was a bit concerned to use an unknown oil neat but tried it anyway. To say it opened my airways would be an understatement, and I had to hold back a coughing fit. I know peppermint is supposed to be good for digestion and I use it for headaches, but by the end of the evening I had a stomach ache. I thought it was irresponsible of the “educator” not knowing how each individual’s body might react, and a lesson learned for me to not be so trusting in the future. Best Regards and I look forward to reading more of your posts.

    • I think this post has pretty much a good list – as for whether they will tell you or not. Of course that is anyone’s guess. I was told by an essential oils seller how a company bought a not so good oil from them and then a better oil and posted the GC/MS certificate for the better oil on their site alongside the worse oil. So folks just aren’t always honest.

      As for the peppermint – I can’t say what to think about that. But I do think I know what company you are talking about.

      I didn’t choose Edens Garden for numerous reasons. I can’t handle evaluating companies for time reasons but also legal issues – they can change what they are doing at any time and I’d be putting myself on the hook too much. Thanks and hope that helps!

  5. Lynn shoemaker says:

    Thank you for taking the time to investigate and sharing your results to The Which Essential Oil Company is best! I am a YL user myself but have recently come across Native American Nutritionals. So I will likely be using both. Your information was extremely helpful to me. I am not an investigative type person although I love having the bottom line. THANK YOU for your time and work on this!

  6. Hi Adrienne, thanks for your evaluation of the different oils companies. If you have time, I would love it if you can comment on the following reasons a friend tells me why she is using YL over any other brand. I’m not totally convinced on any brand right now as essential oils are new to me, but here are my friend’s reasons for choosing YL and I’m curious to find out how you would process what she has to say:
    “”So my main 2 reasons for sticking with YL and never switching to another brand:
    1. Quality does matter. If I’m going to using essential oils for things like sleep, colds, pain, mood, anxiety I want top quality. I want to be sure I am getting something pure. I don’t want to buy a cheaper brand and compromise on quality.
    2. I want to use my oils and to do that I need to know how. I feel like I have a whole community and tons of support so that I can use my oils in a variety of situations and be able to help others do the same. This is a huge thing for me because I love using the oils for all kinds of things.””

    • Hi there. Sure can.

      1. I think I outlined that I sensed a chemical smell in YL oils and today or yesterday another reader said the same thing. I am not saying that they put chemicals in there, but that is my experience. I think that I demonstrated NAN’s commitment to quality. I think they are at the top of the market for quality oils and I have made it very clear to them that I wouldn’t represent them any longer if I ever found a reason to think otherwise. If anything, I am more committed now than when I first mentioned them. Going with NAN is for sure not a compromise on quality.

      2. Yes, the MLMs provide a community and support – that’s for sure. I didn’t have that so much w/ YL but I did w/ doTERRA. I will say, however, that I didn’t care for the “over the top” reliance on oils. I think they are great and can do a lot but you really need to arm yourself w/ other things too. Case in point. I have an achilles issue right now that is very stubborn. I got advice from NAN about what oils to use on it but it wasn’t budging. I got advice about ice massage from a friend and also bought comfrey. The ice massage has been HUGE for me. Now, if I were only leaning on oils and felt that they were the end all and be all, I might not have tried anything else. But I think we need to be realistic. In the MLM essential oils community it seems to me that oils are “it”. I still use the oils occasionally on my achilles and maybe I need to step up all of the above, but the ice does the trick each and every time it acts up.

      Another case in point — those in the MLM oils community will often tell you to use lemon EO to get labels off of jars. Well, that’s a really expensive way to do it but it sure sells oil. I use a wet cloth and elbow grease. Works great and costs me just about nothing. Depending on the label sometimes it works like a charm and quickly.

      I hope that makes sense. If you are interested in a community, perhaps I can think about starting something online….(maybe) but I would be more prone to do a natural remedies group and health group than just an EO group b/c I think there is so much more to health than just EOs. Thanks and I would love to hear what you think about that.

      • I would loved community wellness group! I agree that oils are not the end all. For example all the oils in the world would not align my unbalanced hips …but touching my toes daily did. My unbalanced hips was causing my left leg to carry my body’s weight causing leg ,,knee and ankle problems. Unbalanced hips caused from carrying my children on my left hip. Toe touching 30 x a day was a tip from my chiropractor.

        • I can think about it. I would have to figure out how and how much time to spend. I LOVE that tip. Really? How did that straighten you out? I know one of my hips appears to be the wrong height but I wondered if it was my leg length perhaps.

  7. You’re articles are refreshing, I also have to look in to everything. My first introduction to oils was a free MLM class that I went to as a favor with a friend.. Having a 15 year nutritional background inwas the one in the class with all the questions,,which the MLM distributor couldn’t answer. Like therapeutic ” Grade”. A therapeutic dose of something is 3 x the recommended dose on the label. Yet their lable doesn’t have a recommended dose. I smelled their peppermint, it smelled like a candy cane and not the natural fresh mint I use smell in the woods as a kid. ( peppermint teas are the same…organic smells crisp and clean while the ones that are not smell like that candy cane.)
    Long story short…..wild harvested oils have a greater range and higher therapeutic compounds than farmed. If they are being watered my a mountain stream, that’s even better, they’re getting tons of natural minerals that farmed are not, they are more potent too.
    The MLM’s don’t offers wild harvested oils not do they offer hydrosols…..a spray made from the steam during distillation. 2 strikes out for them. There ARE a few other companies out there offering excellent products. NAN is one of them and another I found is Organic Infusions.
    I will always choose wild harvested oils over farmed when offered…they are the best!

    • Thanks for sharing! Have you tried the NAN peppermint b/c it is a little less herby than most but the owner lets it age for a year to let it mellow. I love it. Glad you’re as pleased with them as I am. Hope to see you around again! Yes, I look into things a ton. Doing it now w/ other personal issues and hoping to have some things resolved today :).

  8. GREAT ARTICLE!!! Thank you so much!! You answered many of my questions from an unbiased opinion!! I am a student at Aromahead Institute and I love getting many opinions…not just one!! Thank you again!!

  9. Hello, I would like to know if you can take any of the essential oils internally? If not, why? Thanks for your time.