At first blush, essential oils are all about beautiful aromas and gentle natural healing.
After you learn a little more, it quickly turns out there are some contentious and controversial issues here as well.
Much of the argument happens on online forums, blogs, and over social networks. If you are new to the topic of essential oils, it can be confusing, and it might even turn you off from aromatherapy entirely.
I’ve put together a guide explaining some essential oil controversies as impartially as I could.
And because I myself am new to essential oils, I will be referring to well-established essential oil experts and published scientific studies as often as possible.
Ready? Get your armor on and let’s dive in.
1. Essential oils and cancer
The controversy in a nutshell: are essential oils a cure for cancer?
The background for this controversy is that there are various in vitro studies (studies in a petri dish) showing the effect of certain essential oil constituents on various types of cancer cells. Also, there are many stories circulating on the Internet with people claiming that essential oils helped them beat cancer.
The flip side is that there is a shortage of controlled in vivo studies (studies done on living beings) that show essential oils can treat cancer. There is some evidence that citrus oils might be preventive when it comes to breast cancer, though simply eating more citrus fruits might be all you need.
Much of this controversy comes down to the supposed usefulness of frankincense essential oil in reducing or eliminating cancers. Frankincense essential oil is commonly claimed to be a powerful cancer-fighting agent — but this is a misleading claim caused by a confusion between frankincense itself and frankincense essential oil.
Frankincense — the resin obtained from various trees in the Boswellia genus — contains chemicals known as Boswellic acids. And Boswellic acids are a promising treatment for different kinds of cancer.
The trouble is frankincense essential oil (the result of steam distilling the frankincense resin, and what you buy from your essential oil company) contains absolutely no Boswellic acid. This is simply a consequence of the steam distillation process, which cannot pull out heavy molecules such as Boswellic acids.
Frankincense CO2 extract (also occasionally available from essential oil companies) might contain Boswellic acid in amounts less than 5%. However, if you are interested in frankincense for its cancer fighting properties, then there are extracts (not essential oils!) that contain as much as 65% Boswellic acid.
Some people point out that — even if they don’t directly affect cancer cells — essential oils can be helpful in managing the side effects of cancer treatments, such as pain or nausea. This is certainly important, but I doubt it explains the amount of publicity this topic has gotten.
And even the side-effects treatment isn’t a straightforward, controversy-free question — Robert Tisserand points out on his blog that essential oils can have a protective effect on our cells, and that includes cancer cells:
Many essential oils have protective & antioxidant effects on our cells, and there is a reasonable chance that they will do the same for cancer cells – protect them from the chemotherapy – which of course would not be a good thing. This opinion is shared by many.
2. Undiluted use of essential oils
The controversy in a nutshell: should you ever put essential oils onto your skin without diluting them in a carrier oil?
Essential oils are normally diluted in a carrier oil before being applied to the skin. And yet, some sources of information suggest applying essential oils “neat” or undiluted to skin. These sources either claim unique benefits or state that certain oils have an “exceptionally mild chemistry” that makes it safe to do so.
Also, if you search around on the Internet, you will quickly come across essential oil recipes advising you to use a few drops of undiluted essential oils on different parts of your body — on you face, on the soles of your feet, on your hands, on the back of your neck.
The flip side is that some people experience an allergic reaction or sensitization even when applying supposedly mild essential oils to the skin in high concentrations. Beyond this, there are lots of scary stories of people who followed advice to use undiluted essential oils and wound up with serious adverse reactions.
Ultimately, there doesn’t seem to be a good reason to ever use essential oils on the skin without diluting them first. Essential oils are extremely concentrated substances relative to the plant from which they come, and they have therapeutic effects even when significantly diluted.
Plus, diluting your essential oils will have benefits beyond preventing an allergic reaction. It will also make the oils evaporate less quickly, and it won’t dry out your skin, as Robert Pappas demonstrates in this video:
3. Therapeutic-grade essential oils
The controversy in a nutshell: is there such a thing as a therapeutic-grade essential oil?
The background for this bit of controversy is that there are hundreds of companies selling and reselling essential oils.
Many of these companies claim that their oils are “therapeutic grade” — high-quality enough to be used for therapeutic purposes. Some even have proprietary, copyrighted terms to describe the quality of their oils.
The flip side is that there is no independent, accepted body that regulates or certifies essential oil quality, or defines what a “therapeutic grade” of essential oils would be. In other words, any company can claim their oils are therapeutic grade, based on their own definition.
Considering the amount of money that’s to be made by selling essential oils, it’s not surprising that most companies claim their oils are therapeutic grade, or 100% pure, or highest quality.
So is there a “therapeutic grade” of essential oils? Some aromatherapy experts will tell you it’s just a marketing term that doesn’t have much substance. Here’s Jade Shutes on the issue:
The truth is that there is no such thing as ‘therapeutic grade’ (or grade b, c, or d) in the sense that some organization or higher power has bestowed on an essential oil line. A grading system, quite simply, does not exist for essential oils. It is a product of marketing and marketing alone.
On the other hand, there clearly are high-quality essential oils that are appropriate for therapeutic use. In this sense, there is a “therapeutic grade” — but its definition depends on who you ask. As Robert Pappas has written:
The truth is that there are MANY therapeutic grade standards. The problem is, which one do you trust?
4. Ingesting essential oils
The controversy in a nutshell: should you ever ingest essential oils?
This is the most genuinely controversial issue on this list.
On the one hand, essential oils are already present in food and flavoring, and we ingest them daily in very small amounts.
Second, there are expert aromatherapists who say that it’s occasionally acceptable to ingest essential oils, as long as you are very well informed of how the oils will act inside your body, and how they might interact with medication you are taking. Some experts say you should only ingest essential oils when advised by an experienced and practicing aromatherapist.
Finally, there are many sources on the Internet that advise you to add a few drops of various essential oils into your water, tea, or juice for therapeutic purposes.
That’s the side for ingesting essential oils, at least in some circumstances. What about the other side?
First off, essential oils are very concentrated plant extracts, and ingesting even a drop of essential oils is equivalent to eating a lot of the original plant. Let’s do a quick and rough calculation for peppermint:
- Let’s say it takes 150 kg of peppermint biomass to produce 1 kg of oil (a conservative estimate based on these ranges on AromaWeb)
- Also, let’s say 20 drops of peppermint essential oil weigh 0.8 g (based on this drops-to-weight research)
- That means it takes 6 grams of peppermint biomass to produce 1 drop of peppermint essential oil (0.8 g/20 drops * 150 kg biomass/1 kg oil)
- There are about 842 “garnish-quality” mint leaves in a kilogram (based on this helpful post)
- That means 1 drop of peppermint essential oil is roughly equal to 5 “garnish-quality” mint leaves (842 leaves/kg * 6 g/drop)
5 juicy mint leaves — would you eat that much? You might, and maybe that’s exactly what you might need in a given condition. But you can see how each drop of essential oil quickly adds up to a lot of plant material.
Another thing to point out is that essential oils can irritate your mouth or stomach lining (again, thanks to their concentrated nature). Putting essential oils into water, juice, or tea will do little to fix this, since essential oils are not water soluble.
Also, ingesting essential oils will get a high amount of their constituents into your bloodstream very quickly.
Some essential oil constituents have drug interactions, while others might have hormone-like effects (more on this below). For many essential oil constituents, we simply don’t have a complete picture of how they will affect us if present in our bloodstream in large amounts.
So should you ever ingest essential oils? I’m afraid I can’t answer that for you, but here are a few essential oil experts and their points of view. First, Robert Tissserand, from an interview posted on his blog:
I have not said people should not ingest essential oils; I don’t believe it’s an absolute no-no. What I do believe is that you need to know what you’re doing. You need to know why you’re doing it; what dose you are taking; how long you are going to be taking it for; what the reason is. […] If you’re talking about very small amounts as you would use in food flavors – if we’re talking about one or two drops a day – that’s fine, that is OK, but if you’re taking a therapeutic dose of essential oils, if you’re taking 10 drops, 20 drops a day just because somebody told you it was a good idea, it’s not a good idea.
Second, here’s an excerpt from Mindy Green and Kathi Keville’s Aromatherapy: A Complete Guide To The Healing Art:
Essential oils are rarely administered orally by aromatherapists. It would likely burn the mucous membranes of your mouth. It is also easy to overdose because essential oils are so concentrated. Learning to safely ingest oils is not be entered into lightly and requires clinical training.
5. The MLM controversy
The controversy in a nutshell: are companies like doTerra and Young Living harmful?
Even though there are hundreds of essential oil companies, only a handful of companies account for a majority of the aromatherapy market.
Two unique companies — doTerra and Young Living — are among these big players. These two companies share a particular company structure, known as multi-level marketing (MLM).
Here’s what that means: MLM companies basically outsource their sales and marketing to anybody who is willing to pay a sign-up fee (people who take on this role are commonly known as “reps”). There’s another important ingredient — reps can make money by selling directly or by referring other people who will become reps.
In the case of essential oils, this setup has led to a lot of exaggerated or outright deceptive marketing, originating either at the companies themselves or in the hierarchy of reps.
In fact, the FDA even sent warning letters to doTerra and Young Living to try to stop them and their reps from making unsubstantiated claims such as “essential oils protect you against the ebola virus”.
And it’s not just the FDA. Here’s aromatherapy expert Lora Cantele on the topic:
Much of the information shared on social memes and on Facebook and Pinterest is derived from Multi-Level Marketing companies whose interest is in selling oils, not health and wellness. Their advice often recommends overuse and copious amounts of essential oils in their protocols. In addition, their dropper sizes yield drops of oil that are twice the size of those generally sold. All in an effort to sell MORE oils.
The fact is, the MLM essential oil companies directly (or indirectly through their reps) recommend controversial practices such as undiluted use of essential oils or ingestion.
On top of this, their oils are typically much more expensive than equally good alternatives.
So can anything be said in defense of MLM essential oil companies?
First off, they have certainly been responsible for the growing popularity of essential oils, and they continue to have many devoted customers (hence the controversy).
Second, aside from their marketing practices, it’s likely that both companies generally sell quality oils (though both companies have previously faced accusations of selling batches of adulterated oils).
6. Essential oils as hormone disruptors
The controversy in a nutshell: do some essential oil constituents mimic the hormone estrogen?
In 2007, the New England Journal of Medicine published a case study involving lavender and tea tree essential oils.
The study made a worrying claim: 3 preadolescent boys grew breasts because they used products (shampoos, lotions) that contained lavender and tea tree oils.
Robert Tisserand has addressed that particular study in detail, and has questioned whether either lavender or tea tree were in fact to blame. Also, a study done in 2013 on rats failed to find any in vivo estrogenic effect of lavender oil, even in very high doses.
What about other essential oils?
Tisserand and Young’s Essential Oil Safety points to trans-anethole — a constituent found in anise, star anise, fennel, and myrtle essential oils — for possible estrogenic effects.
Also, the Internet is full of claims that some essential oils have a balancing effect on hormones, though I haven’t seen any research to support such claims directly.
Our endocrine system is very complex, and it’s certainly possible that some essential oil constituents could interact with hormones or hormone production in different ways.
If this is indeed true, then the outcome might be beneficial in some cases (the hormone balancing claim from above)… while it might be harmful in other cases (during pregnancy, breastfeeding, or in kids).
7. Essential oils are a scam
The controversy in a nutshell: is aromatherapy another alternative medicine scam, without any substance or research to back it up?
I hesitated in including this point, because most of the people who are likely to read this post will already be convinced of the genuine uses of various essential oils.
However, I believe this might be the biggest essential oils controversy when you look at the population in general. For example, here’s Harriet Hall, MD, writing about doTerra and essential oils on the site Science-Based Medicine:
The published evidence is sparse to nonexistent. There are clinical studies to support a few of the recommended uses, but they are generally poorly designed, uncontrolled, and unconvincing. Research is difficult, because patients can’t be blinded to the odors, and mental associations and relaxation could account for most of the observed effects.
Now, if you consider the controversies I’ve covered so far — the unsubstantiated or misleading claims about cancer, the recommendations to use essential oils in unsafe ways, the questionable business practices of some of the biggest essential oil companies — then it’s easy to imagine how somebody who’s new to essential oils might get a bad sense that this is all just a hoax or a scam.
However, it’s definitely not true that the published evidence on the use of essential oils for health is sparse or nonexistent.
For example, I collected the research papers I could find on the therapeutic uses of lavender oil alone. I found over 50 papers worth citing, and that doesn’t include papers I didn’t cite because they had similar conclusions.
Other popular essential oils, such as tea tree oil or peppermint, probably have comparable numbers of scientific studies to back up their recommended uses.
In short — while there are plenty of exaggerated claims about the power of essential oils, this doesn’t take away from the therapeutic uses in which essential oils can be genuinely helpful.
What’s your stance on these controversies? I’d love to hear your opinion, particularly if you disagree strongly with something I’ve written. Let me know in the comments below.