Diquat

As of December 2025, there are currently 46 diquat products registered for use in Canada. Diquat formulations can also be used with glyphosate formulations.

Weedkiller ingredient widely used in US can damage organs and gut bacteria, research shows    Diquat is banned in the UK, EU, China and other countries. The US has resisted calls to regulate it. (The Guardian, 6 July 2025)

The herbicide diquat used to replace glyphosate in Roundup and other weedkiller products can kill gut bacteria and damage organs in multiple ways, new research shows.

But the new piece of data suggests diquat is more toxic than glyphosate, and the substance is banned over its risks in the UK, EU, China and many other countries.. and Roundup formulas with the ingredient hit the shelves last year.

Diquat is also thought to be a neurotoxin, carcinogen and linked to Parkinson’s disease. An October analysis of EPA data by the Friends of the Earth non-profit found it is about 200 times more toxic than glyphosate in terms of chronic exposure.

The new review of scientific literature in part focuses on the multiple ways in which diquat damages organs and gut bacteria, including by reducing the level of proteins that are key pieces of the gut lining.    The research further scrutinizes how the substance harms the kidneys, lungs and liver.    Meanwhile, it seems to attack the lungs by triggering inflammation that damages the organ’s tissue. More broadly, the inflammation caused by diquat may cause multiple organ dysfunction syndrome, a scenario in which organ systems begin to fail.

SNAP Comment:  There are currently 45 pesticide products containing diquat registered in Canada. It is registered as a dessicant at least since 1987.