Oregano oil is being marketed with a variety of health claims, including as a treatment for various infections, inflammatory disorders, and skin conditions. This TikTok video by an “Ayervedic specialist” is typical of the claims made for this product.
The claims suffer all the usual problems of the supplement industry, which we can go through them in some detail. But here is the executive summary – claims for oregano oil are based partly on traditional use and partly on pre-clinical data. There is almost no scientific data involving people. Proponents are extrapolating from the basic science to clinical claims, which is not valid and has proven extremely unreliable. They justify this with the usual appeal-to-nature fallacious arguments.
What does the basic science say? Here is one of the better studies. It shows that oregano oil in vitro has bactericidal activity, likely through disruption of the bacterial cell membrane. They also demonstrate potential activity as a topical treatment for burn infections. However, I note that they did not use a proper control comparison. The two treatment arms contained different concentrations of oregano oil mixed with grape seed oil. For some reason they did not include a treatment arm with grape seed oil only (a pretty obvious control).
Other research shows potential anti-inflammatory properties. These, however, are all biomarker-based studies. There is no research demonstrating a clinically relevant effect in humans. Showing changes in biomarkers of inflammation is not very compelling on it’s own. I would also note that anti-inflammatory effects are not generally what you want when trying to fight off an infection. So claiming anti-infection and anti-inflammatory effects at the same time is a bit of a contradiction.
And of course there is the almost ubiquitous claim for supplements of antioxidant activity. However, there are no proven health benefits to eating antioxidants. And again, oxidative compounds are actually used by the immune system to kill invaders, to a genuinely potent antioxidant could impair your immunity.
Even if we stipulate a probable anti-microbial effect of oregano oil at a high enough concentration, dose, and delivery mechanism, there is still a long way to go before making clinical claims. Topical use is a much easier bar to clear, because we don’t have to deal with bioavailability, metabolism, distribution in the body, pharmacodynamics and pharmacokinetics. As a topical antimicrobial oregano oil has promise, but it can also cause skin irritation and rashes, even without an allergic reaction. We therefore need human clinical trials looking at specific formulations and doses.
For internal use there are a host of factors that we simply do not know, because of the utter lack of human clinical trials. Do the active ingredients get absorbed, how are they metabolized, how are the metabolites distributed in the body, how quickly are they eliminated, and what are the net clinical risks and effects? Is it safe in pregnancy and breast feeding? What are the interactions with other drugs?
Oregano oil has a host of potentially serious side effects and interactions with medications. It can increase blood thinning, resulting in a risk of bleeding. It can also interact with blood sugar lowering agents, and can therefore be dangerous in anyone taking medication for diabetes.
In the world of scientific medicine, we may begin with a promising agent, like oregano oil, but then we need to study is in vitro, then in animals, and finally in a series of clinical trials in humans for every potential clinical use and in special populations. Only then can we make clinical claims of safety and efficacy, know the proper dose and treatment regimen, and make informed decisions about risk vs benefit.
What you absolutely cannot legitimately do it leap over a decade or more of necessary clinical research and go directly from preliminary in vitro data to clinical claims. But that is exactly what proponents of oregano oil are doing. The video by the Ayurvedic specialist make very clear the process they use – just make up magical thinking about the product based on mystical appeal-to-nature nonsense.
She claims that oregano oil just knows what is bad in your body and it magically flushes it away. The universe simply does not work that way. At the very least, this should be considered a faith-based claim, not a science-based or reason-based claim, and it is certainly not evidence-based.
