Roundup is the brand name of a systemic, broad-spectrum glyphosate-based herbicide originally produced by Monsanto, which Bayer acquired in 2018. Glyphosate is the most widely used herbicide in the United States. The main active ingredient of Roundup is the isopropylamine salt of glyphosate. Another ingredient of Roundup is the surfactant POEA (polyethoxylated tallow amine).

Some studies and legal cases have suggested a link between glyphosate and harmful health effects, such as cancer, while others claim its safety at approved usage levels. The U.S. Environmental Protection Agency (EPA) currently considers glyphosate safe when used correctly, but public concern and ongoing research may influence future assessments and policy decisions.