New research has revealed that diquat, a herbicide ingredient increasingly used as a substitute for glyphosate in weedkillers like Roundup, poses serious health risks. Although glyphosate has been phased out in several regions due to its controversial health effects, diquat—while considered even more toxic—is still widely used in the U.S.
This ingredient is banned in countries such as the UK, EU member states, and China, yet the U.S. Environmental Protection Agency (EPA) continues to allow its usage. Experts warn that this switch is a “regrettable substitution,” replacing one harmful substance with another potentially more dangerous one.
Diquat’s Extreme Toxicity Threatens Vital Organs, Gut Health, and Human Biological Functions
Diquat is believed to act as a neurotoxin, carcinogen, and may be linked to Parkinson’s disease. A study by Friends of the Earth suggests diquat is up to 200 times more toxic than glyphosate when it comes to chronic exposure.
The new review highlights how diquat damages the body on multiple fronts, notably by disrupting gut health and damaging major organs like the kidneys, liver, and lungs. It lowers the production of essential gut proteins, weakens gut lining, and allows harmful substances to enter the bloodstream, leading to systemic inflammation and poor nutrient absorption.
Diquat Replaces Glyphosate in U.S. Weedkillers Despite Global Bans and Rising Health FearsIn addition to harming the gastrointestinal system, diquat causes structural and functional damage to vital organs. It breaks down kidney cell membranes, interferes with cell signaling, inflames liver tissue, and damages lung cells through inflammation.
These cascading effects can potentially lead to multi-organ dysfunction syndrome—a critical condition where several organ systems fail simultaneously. Although much of the current data stems from rodent studies, researchers emphasize the need for more long-term studies involving low-dose human exposure.
Regulatory Failures Leave Diquat Unchecked Despite Mounting Evidence of Severe Health Risks
Despite growing scientific concern, diquat remains under the radar of both regulators and advocacy groups in the U.S. The EPA has yet to initiate a review of the chemical, and nonprofit organizations are still preoccupied with ongoing regulatory battles over glyphosate, paraquat, and chlorpyrifos.
These chemicals, banned in other nations, continue to be prevalent in U.S. agriculture, leaving little room or resources for tackling diquat’s risks. This underscores the weakness of U.S. pesticide regulations compared to international standards.
Experts argue that the EPA’s sluggish response stems from systemic flaws in the U.S. pesticide regulatory framework. The agency often appears constrained, unable or unwilling to ban dangerous chemicals even when evidence of harm is substantial.
Legal obstacles, industry influence, and a regulatory culture that views toxic pesticides as a “necessary evil” have all contributed to the continued use of hazardous substances like diquat. As a result, the U.S. lags behind much of the world in protecting public health from harmful agrochemicals.
