Avocado oil has become a staple in healthy kitchens across the country. But, unfortunately, the oil sitting in your cupboard is most likely rancid. And, worse yet, there’s a chance it’s not even avocado oil at all.

In a new study published in the journal Food Control, reachers extensively looked into the quality and purity of commercial avocado oil for the first time. What they found was shocking, to say the least. Of the 22 domestic and imported avocado oil samples they tested (which came from grocery store shelves and online), 82 percent were either rancid or mixed with other oils—even if they were labeled as “pure” or “extra virgin” avocado oil. In fact, three samples with those labels contained 100 percent soybean oil (aka no avocados at all), and six samples contained large amounts of sunflower, safflower, and soybean oil.

So, how does something like this happen? Because avocado oil is such a new product, Selina Wang, PhD, who led the study, said it isn’t regulated, making it really easy for companies to falsify the information on labels. “Because there are no standards to determine if an avocado oil is of the quality and purity advertised, no one is regulating false or misleading labels,” she said in a press release. “These findings highlight the urgent need for standards to protect consumers and establish a level playing field to support the continuing growth of the avocado oil industry.”

Through this study, researchers only found two brands that were actually pure and still fresh by the expiration date: Chosen Foods 100% Pure Avocado Oil and Marianne’s Avocado Oil. As for the virgin oils, CalPure Extra-Virgin Avocado Oil was found to be “pure and fresher than the other samples in the same grade.” All the others—some of which you might have in your pantry—didn’t live up to what’s on the label. Not only are they making you pay high prices for low-quality oil, but they’re also potentially hurting your health. Instead of reaping the benefits of avocado oil, you’re instead unknowingly dousing your food with a highly-refined option.

Luckily, the researchers provided some helpful tips for you to be able to determine what your avocado oil should actually taste like if it’s high-quality. “In general, authentic, fresh, virgin avocado oil tastes grassy, buttery, and a little bit like mushrooms,” they write. “Virgin avocado oil should be green in color, whereas refined avocado oil is light yellow and almost clear due to pigments removed during refining.” And when it comes to determining whether your avocado oil is rancid or not, do a smell test. If it’s stale, it has a play dough-like smell.

Hopefully there are more regulations on avocado oil soon. But until then, shop smart and stick to the brands you can trust.

These are the dietitian-backed avocado benefits you should know about: