glyphosate

Glyphosate is a broad-spectrum systemic herbicide whose active ingredient is glyphosate, N-(phosphonomethyl)glycine. It was developed in the 1970s and is sold under various brands, most notably Roundup. It is widely used in agriculture, forestry, and urban settings to control weeds, often with glyphosate-tolerant crops.

Glyphosate inhibits 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in the shikimate pathway, blocking synthesis of essential aromatic amino acids in plants and causing death. Animals lack this pathway, so the enzymatic target is not found in them, though concerns exist about non-target organisms and formulated products.

It is typically absorbed through leaves and translocated to growing points. It is non-selective and affects many plant species. In the environment it binds to soil and can persist for weeks to months depending on conditions; degradation is largely microbial. Runoff can introduce it to water, affecting some aquatic life.

Safety and regulation are debated. Some authorities conclude no evidence of carcinogenicity at typical exposure, while others classify glyphosate as probably carcinogenic based on different data. Regulatory status varies by country and over time, with approvals tied to usage guidelines, residue limits, and restrictions on formulations.

Resistance to glyphosate has emerged in many weeds, prompting integrated management and the development of alternative herbicides and crop traits.