At areme, we’re often asked questions like “Is this essential oil truly 100% pure?” or “How can I tell if it’s genuine?” As a brand that produces and offers essential oils, we’ve learned a lot along the way—and we’d like to share with you what we’ve come to understand about adulteration in essential oils.
※This article has been written with care to ensure accuracy, but it is intended for general informational purposes only. Please use the information at your own discretion.
What does “adulterated” mean?
Adulteration refers to the act of altering or “stretching” essential oils, either by blending them with other oils, adding synthetic compounds, or diluting them with solvents. These changes aren’t always obvious, but they can affect the scent, therapeutic quality, and even safety of the oil.
Rather than being a rare practice, adulteration is surprisingly common. Some industry reports and peer-reviewed studies have estimated that up to 80% of commercially available essential oils may be adulterated in some form—particularly those in high demand like lavender, rose, and frankincense.
Why does adulteration happen?
Adulteration doesn’t always stem from ill intent. Often, it arises from practical challenges in the supply chain:
- High production costs – It can take hundreds or even thousands of kilograms of plant material to produce just one kilogram of oil. For example, rose oil yields only 0.01–0.05%, making it exceptionally expensive.
- Crop failures and climate stress – Drought, extreme weather, or poor harvests can reduce oil yield or alter its chemical profile.
- Inconsistent supply and high demand – When nature can’t keep up with global appetite for oils like lavender or frankincense, manufacturers may “adjust” their oils to meet volume or quality expectations.
- Desire for uniformity – Pure oils often vary slightly in scent between batches. Standardization can be used to create a more consistent product experience.
Understanding these reasons helps frame adulteration not just as a problem—but as a complex industry reality we can learn to navigate.
The many faces of adulteration
Here are some common types:
- Adding synthetic aroma chemicals (like synthetic citral, linalool, or vanillin)
- Blending with cheaper essential oils (e.g., using geranium to stretch rose oil)
- Adding isolates from other plants (e.g., linalool from lavandin into lavender oil)
- Diluting with solvents or fixed oils (like ethanol or carrier oils)
- Manipulating component ratios to fit certification standards (known as "standardization")
None of this is illegal per se—but it's not always transparent either. And while some blends may still smell nice, they often lack the complexity, therapeutic properties, and safety of pure essential oils.
A closer look: Lavender, rose and tea tree oil
Adulteration tends to occur most often in oils that are difficult or costly to produce.
Take lavender, for example. Due to climate-related challenges such as drought and extreme heat, production yields have dropped in some regions, and studies have shown that the chemical profile of the oil can shift under stress. Meanwhile, global demand for lavender oil remains high. This imbalance creates a strong incentive to standardize or modify oils to meet expectations.
Rose oil is another case. With an average yield of just 0.015–0.048% from fresh flowers, it takes up to 3,000 kg of petals to produce a single kilogram of oil. Given its rarity and cost, some suppliers use small amounts of geranium or ethanol to help replicate the rose aroma—a practice confirmed in several industry reports.
Tea tree oil also presents an interesting case. To safeguard quality, the Australian government established a standard requiring tea tree oil to contain at least 30% terpinen-4-ol and no more than 15% 1,8-cineole. While this was meant to protect authenticity, it has also led to the practice of synthetically adjusting oil compositions to meet this ratio—a form of adulteration referred to as standardization.
Including a small amount of another natural oil doesn’t necessarily mean the product is harmful—but it does change the nature of what’s in the bottle.
So how can you tell?
Here are a few accessible ways that might help spotting adulteration:
- Check the label. Look for botanical names, distillation methods, lot numbers, and country of origin.
- Trust your nose. Pure essential oils tend to have multi-layered, evolving aromas. Adulterated oils often smell flat, overly sharp, or overly sweet.
- Request technical documents. Reputable sellers will often provide a GC-MS report or batch-specific data upon request.
- Watch the price. If it seems too good to be true—like rose oil at ¥1,000 for 10ml—it probably is.
- Ask questions. A transparent brand will be happy to share how and where their oils are made.
Why it matters
The word “adulteration” might sound a little strong to some people. However, the reason we chose to write about this topic is not to create fear, but to help more people gain accurate knowledge about essential oils and feel confident in making informed choices for themselves.
Not all adulterated oils are necessarily dangerous. If the added substances are naturally derived and the aroma feels pleasant to you, it is entirely up to your personal judgment whether to use them.
By understanding what components are added, and why, we believe you can gain a deeper perspective when selecting oils and feel more assured in your daily choices. Whether you’re enjoying a custom blend or discovering a new oil, we hope this knowledge will be of some help to you.