Glyphosate: What It’s Doing to Our Bodies—and to Life on Earth
For decades, glyphosate—best known as the active ingredient in Roundup—has been the world’s most widely used herbicide. It’s sprayed on farm fields, roadsides, orchards, home lawns, and even used as a pre-harvest “dry-down” on some crops. Supporters call it efficient and safe; critics argue it’s quietly reshaping ecosystems and human health. As usual, the truth is nuanced—and important.
Below, we unpack what glyphosate is, how it travels through soils and waters, its effects on insects and wildlife, and what the science says about glyphosate and the human body.
What is glyphosate—and why is it everywhere?
Glyphosate kills plants by blocking the shikimate pathway (the EPSPS enzyme), which plants and many microbes need to make aromatic amino acids.
Mammals don’t have this pathway—but our gut microbes do, which is one reason researchers study glyphosate’s microbiome effects. Regulatory agencies like the U.S. EPA and EFSA say current approved uses don’t pose risks to the general population; the IARC classifies glyphosate as “probably carcinogenic to humans (Group 2A).” Same chemical, different lenses. So what’s the truth?
Soil & Water: how it moves, lingers, and reshapes microbial life
Soils. Intensive glyphosate use can shift soil microbial communities and select for resistant weeds and microbes, with downstream plant-health effects, according to a large 2018 review.
Waters. U.S. Geological Survey monitoring has found frequent detections of glyphosate and its metabolite AMPA in streams, rivers, and soils across diverse landscapes. That confirms widespread environmental presence. It’s getting everywhere.
Pollinators & Biodiversity: bees, butterflies, and beyond
Honey bees. Sub-lethal glyphosate exposures disrupt bee gut microbiota and can increase susceptibility to pathogens—demonstrated in controlled experiments. This is not the only driver of bee stress, but it’s a plausible piece of the puzzle. Honey bee populations continue to face significant declines, with commercial honeybee colony losses projected to reach between 60% and 70% in 2025
Monarch butterflies. The story is mostly habitat: widespread glyphosate use in herbicide-tolerant cropping systems reduced milkweed in and around fields, a primary monarch host plant—contributing to declines, though other stressors (climate, other pesticides) matter too.
Are we killing our precious pollinators off with poisons?
The Human Body: what the evidence shows (and what it doesn’t)
Gut & Microbiome
Glyphosate was designed to block a metabolic pathway in plants and microbes. We don’t have that pathway—but our gut bacteria do. Early studies suggest glyphosate can change the balance of our gut microbiome, favoring harmful microbes over beneficial ones. That may explain rising connections between glyphosate, leaky gut, and digestive problems.
Hormones & Endocrine System
Some research shows glyphosate (and especially glyphosate-based herbicide mixtures) can act as endocrine disruptors—chemicals that mess with hormone signaling. Estrogen pathways are one example. While regulators debate the extent of risk, the evidence is concerning enough that many scientists call for caution.
Thyroid
The thyroid is sensitive to environmental toxins, and glyphosate is being studied for potential links. Some studies suggest it may interfere indirectly—through its effects on the gut or immune system. While the science isn’t settled, the thyroid is definitely on the list of “organs of concern.”
Brain & Nervous System
Animal and lab studies show glyphosate can trigger inflammation and oxidative stress in the brain, leading to changes in mood, behavior, and memory. Human studies are more limited, but some links have been found between glyphosate exposure and neurological symptoms.
Liver & Kidneys
Your liver and kidneys are your body’s detox organs—and glyphosate adds to their workload. Long-term, low-level exposures in animals show liver stress, fatty liver changes, and kidney dysfunction. Human studies are ongoing, especially in farming communities with higher exposure.
Autoimmunity
Glyphosate may not directly “cause” autoimmune disease, but it could play a role by altering the gut barrier and immune balance. Think of it as one more stressor that tips the immune system toward attack mode in sensitive people.
Cancer
This is one of the most debated areas:
The World Health Organization’s cancer arm (IARC) classified glyphosate as “probably carcinogenic,” based on studies showing a link to non-Hodgkin lymphoma.
EPA and European regulators disagree, saying glyphosate is “unlikely to cause cancer” at current exposure levels.
What this really means: glyphosate can cause cancer under certain conditions. The question is whether typical levels in food and environment are high enough to be risky. And we just don’t currently have the data to show this, it does NOT mean that glyphosate is safe or that it does not cause cancer. Glyphosate is a poison, therefore, it’s logical to understand that it’s most likely a poison in humans, too.
Practical steps you can take:
Choose organic when possible (glyphosate isn’t allowed in organic farming).
Wash produce well, though residues may still remain inside.
Support regenerative farmers who prioritize soil and pollinator health.
Reduce your own lawn/garden herbicide use—small changes matter. There are ways to treat for pests without glyphosate.
Educate others about the harms of glyphosate when you have the chance.
Choose organic textiles, prioritize organic cotton over conventional cotton.
References
International Agency for Research on Cancer (IARC). Monograph Vol. 112: Glyphosate—Group 2A “probably carcinogenic.” 2015. IARC
U.S. Environmental Protection Agency (EPA). Glyphosate—Human Health & Ecological Risk. Current conclusions on risks at approved uses. US EPA
European Food Safety Authority (EFSA). Peer review of glyphosate risk assessment (2023): no critical areas of concern identified; ECHA RAC: glyphosate unlikely to be carcinogenic. EFSA Journal
van Bruggen AHC, et al. Environmental and health effects of the herbicide glyphosate. Sci Total Environ. 2018 (review on soil microbes, resistance). PubMed
USGS. Glyphosate prevalent in U.S. streams and rivers; Glyphosate/AMPA occur widely in U.S. soils and sediments. 2020–. USGS+1
Motta EVS, et al. Glyphosate perturbs the gut microbiota of honey bees. PNAS. 2018; and follow-up 2020. PNASPubMed Central
Environment America (summary with citations). Glyphosate drove past monarch declines; neonics now key factor in recent losses. 2024. (Context on multiple stressors.) Environment America
Walsh L, et al. Impact of glyphosate on the human gut microbiome. (2023 review). PubMed Central
Lehman PC, et al. Low-dose glyphosate alters gut microbiota (animal). 2023. ScienceDirect
Muñoz JP, et al. Glyphosate and the key characteristics of an endocrine disruptor. 2021 (review); EFSA 2017 weight-of-evidence against EDC classification for glyphosate. ScienceDirectEFSA Journal
Romano RM, et al. Could glyphosate be an endocrine disruptor? 2021 (mini-review; notes thyroid associations in farmers). PubMed Central
Winstone JK, et al. Glyphosate infiltrates the brain and increases pro-inflammatory signaling. J Neuroinflammation. 2022; plus 2024 neuroinflammation study. BioMed Central+1
Myers JP, et al. Concerns over glyphosate-based herbicides & risks to health. Environ Health. 2016 (liver/kidney oxidative stress evidence). BioMed Central
ATSDR. Toxicological Profile for Glyphosate (health effects summary). 2023. ATSDR