A landmark study offers some of the strongest evidence to date that glyphosate and glyphosate-based herbicides (GBHs) pose a significant cancer risk, reinforcing the importance of organic farming, which bans their use. The two-year study tracked rats from prenatal life through adulthood, and found a statistically significant, dose-related increase in both benign and malignant tumors across multiple organs. These included cancers of the blood, skin, liver, thyroid, ovaries, kidneys, bones, and mammary glands. Notably, nearly half of leukemia-related deaths occurred in the first year, suggesting that early-life exposure may be particularly dangerous. 

In the study, male and female rats were exposed to glyphosate and two glyphosate-based herbicides: Roundup Bioflow (used in the EU) and RangerPro (used in the U.S.), beginning on gestational Day 6 and continuing through 104 weeks of age. Even at low doses (equivalent to or below the European Union’s current safety thresholds), cancer risk increased significantly, with commercial GBH formulations found to be more carcinogenic than glyphosate alone, likely due to toxic co-formulants that enhance glyphosate’s absorption and effects. 

Glyphosate remains the most widely used herbicide in the United States, applied to nearly 90% of corn, soy, and cotton acreage, as well as in orchards, vineyards, and public parks. Its residues are pervasive, frequently detected in food, water, and even breast milk. By contrast, organic farming systems prohibit the use of glyphosate and other synthetic herbicides, offering a science-backed approach that reduces health risks for farmers and communities.  

As concerns about glyphosate’s health impacts continue to grow, this study highlights the protective power of organic agriculture and adds urgency to calls for stronger regulations and increased investment in organic agriculture research, infrastructure, and policy.