Even Tiny Doses of Glyphosate Can Cause Health Problems Across Generations, New Study in Mice Shows

Even extremely small amounts of the herbicide glyphosate can harm gut health, disrupt metabolism, and change behavior in mice, scientists say. The effects aren’t limited to the exposed animals—they pass on to their children and grandchildren.

The new research, to be published Nov. 1 in Science of the Total Environment, suggests that prenatal exposure to glyphosate disrupts gut bacteria, hormones, and brain signaling in mice. Even at doses far below current safety guidelines, the herbicide is linked to inflammation, metabolic problems involving appetite and blood sugar, and signs of neurological risk.

“Our findings demonstrate that prenatal glyphosate exposure, at doses consistent with real-world dietary intake, can disrupt multiple physiological systems across generations,” the researchers say.

Glyphosate, best known as the active ingredient in Roundup^®, is the most widely used herbicide in the world, with more than 160 million kilograms applied annually in North America. Once thought safe because it targets a plant-specific pathway absent in humans, glyphosate may still indirectly harm people by disrupting gut microbes, immune responses, and hormone systems — especially during pregnancy and early life, according to emerging evidence.