The vast majority of soybeans grown today are genetically modified. In the United States, 96 percent of soybean acreage is planted with genetically engineered varieties as of 2025. If you buy a conventional soy product in the U.S. without checking the label, it almost certainly contains GMO soy.
Why Most Soybeans Are Genetically Modified
The dominant genetic modification in soybeans is herbicide tolerance. These plants are engineered to survive exposure to powerful weed-killing chemicals like glyphosate, glufosinate, and dicamba, allowing farmers to spray their fields without harming the crop itself. The first commercially available GMO soybean was introduced in 1996, developed by Monsanto under the name “Roundup Ready” because it could withstand Roundup herbicide. Adoption was rapid: farmers found it far simpler to manage weeds by spraying a single herbicide over the entire field rather than using older, more labor-intensive weed control methods.
A second trait, insect resistance, uses genes from a naturally occurring soil bacterium to help the plant produce proteins that kill certain pests. This trait became commercially available for soybeans in South America in 2013. Some soybean varieties now stack both herbicide tolerance and insect resistance into the same seed. Other modifications exist too, including soybeans engineered to produce healthier oil profiles that can replace oils containing trans fats, though herbicide tolerance remains by far the most widespread trait.
Environmental Effects of GMO Soybeans
The environmental picture is more nuanced than either side of the GMO debate tends to acknowledge. At the global level, GMO herbicide-tolerant soybeans have led to a small net decrease in the total weight of herbicide applied, roughly 3 million fewer kilograms of active ingredient than would have been used on conventional crops between 1996 and 2020. However, in the United States specifically, the average amount of herbicide applied per hectare on GMO soybean fields actually doubled over that same period. Farmers increasingly relied on herbicides as weeds developed resistance, requiring heavier or additional applications.
Despite that increase in volume, the overall environmental footprint of those herbicides has improved. Researchers using an environmental impact scoring system developed at Cornell University found that the herbicides used on GMO soybeans are generally less toxic to groundwater and surrounding ecosystems than the ones they replaced. Globally, the environmental impact of herbicide use on GMO soybeans improved by 12.5 percent compared to what conventional farming would have required. Insect-resistant soybean varieties in South America contributed a 23.9 million kilogram reduction in insecticide use, with a 17.8 percent improvement in environmental impact.
Safety of GMO Soybeans
Every major food safety authority that has evaluated GMO soybeans has found them to be as safe as conventional soybeans. The FDA states plainly that GMO foods are “just as safe as non-GMO foods” and that research since the 1990s has consistently supported this conclusion. A comprehensive analysis by the National Academies of Sciences, Engineering, and Medicine found no connection between GMO food consumption and cancer rates, noting that cancer patterns in the United States (where GMO consumption is high) are similar to those in Europe and the United Kingdom (where it is much lower).
GMO soy does not introduce new allergens. If you’re allergic to conventional soy, you’ll also react to GMO soy. If you’re not allergic to conventional soy, GMO soy won’t trigger a reaction either. The genetic modifications change specific traits in the plant but don’t alter its fundamental nutritional or allergenic profile.
How to Tell if a Soy Product Is GMO
U.S. federal law now requires disclosure of bioengineered ingredients. Soybean is on the USDA’s official List of Bioengineered Foods, which means products containing GMO soy must be labeled. You’ll see one of several possible disclosures: the text “Bioengineered food” or “Contains a bioengineered food ingredient,” a green and white circular symbol with the letters “BE,” a QR code or digital link, or a text message number you can use to get more information. These labels typically appear near the manufacturer’s information on the back of the package.
If you want to avoid GMO soy specifically, two certifications are worth knowing. The Non-GMO Project Verified label (a butterfly logo) requires testing of major high-risk ingredients and sets a contamination threshold of 0.9 percent, the same level that triggers mandatory labeling in the European Union. Nearly a third of shoppers actively look for this label. USDA Organic certification also excludes GMOs by rule, though the organic program does not require GMO-specific testing. Many consumers and advocacy groups consider products carrying both certifications to be the most reliable option for avoiding genetically modified ingredients.
GMO Soybean Rules Vary by Country
While GMO soybeans dominate farmland in the United States, Brazil, and Argentina, many countries restrict or ban them. Russia banned both cultivation and importation of GMO crops, though it reversed its import ban on soy in 2020. In the European Union, individual member countries can block GMO crop cultivation, and 19 members, including Germany and France, have done so. Countries like Algeria and Venezuela ban both growing and importing GMO crops entirely.
The global regulatory landscape creates a patchwork. Some countries permit importing GMO soybeans for animal feed or processing but prohibit planting them domestically. Others allow cultivation with no restrictions. As of a 2015 count, 38 countries banned GMO crop cultivation, with significant restrictions existing in roughly 60 more. This means the soy products you encounter can vary dramatically depending on where you live and where the soybeans were sourced.