Glyphosate, Autism & ADHD: What Parents Should Know

Could environmental exposures such as glyphosate play a role in childhood autism, ADHD, or behavioural concerns?

Autism spectrum disorder (ASD), ADHD, learning difficulties, and other behavioural concerns are complex conditions influenced by multiple factors, including genetics, biology, and the environment.

One environmental exposure receiving increasing research attention is glyphosate – a widely used herbicide.

While current research does not prove that glyphosate causes autism or behavioural disorders, some studies have identified potential links between pesticide exposure, neurodevelopment, oxidative stress, inflammation, and the gut microbiome.

What is glyphosate?

Glyphosate is a herbicide used extensively in agriculture and weed control. People can be exposed through food, water, occupational activities, and the environment.

Glyphosate blocks the shikimate pathway which is a biochemical pathway found in plants and some microorganisms. While humans do not have this pathway, many microorganisms in the gut do. This has led researchers to investigate whether glyphosate could influence the gut microbiome and gut-brain axis.¹

Glyphosate and brain development

Pregnancy and early childhood are important periods of brain development. Researchers are investigating whether environmental exposures during these periods could influence neurological development.

Laboratory and animal studies have identified several possible mechanisms through which glyphosate or glyphosate-based herbicides could affect neurological function, including:

• Oxidative stress
• Neuroinflammation
• Mitochondrial dysfunction
• Changes in neurotransmitter pathways
• Alterations in the gut microbiome
• Changes in gut-brain communication

These findings provide possible biological explanations for further research, but animal and laboratory studies cannot establish that the same effects occur in humans.¹⁻³

Is glyphosate linked to autism?

Some human research has reported an association between prenatal pesticide exposure and autism.

A 2019 population-based study in California found that estimated prenatal exposure to glyphosate was associated with increased odds of autism spectrum disorder in children.⁴ However, the study estimated exposure based largely on proximity to agricultural pesticide applications rather than measuring glyphosate directly in individual mothers.

Other research has produced different findings.

Importantly, a 2025 Canadian pregnancy cohort study measured glyphosate and its metabolite (i.e. breakdown product) aminomethylphosphonic acid (AMPA) in maternal urine and found no significant association between prenatal glyphosate exposure and children’s cognitive, social, or behavioural functioning.⁵

This illustrates an important point: the evidence is currently mixed, and more high-quality human research is needed.

What about ADHD and behavioural disorders?

Research has also investigated whether pesticide exposure may be associated with ADHD and other behavioural concerns.

A meta-analysis examining maternal pesticide exposure found associations with autism and ADHD.⁶ However, the studies included different types of pesticides, exposure levels, and methods of measuring outcomes.

Therefore, these findings cannot be interpreted as evidence that glyphosate specifically causes ADHD or other behavioural disorders.

The gut-brain connection

One particularly interesting area of research is the relationship between the gut microbiome and the developing brain.

The gut microbiome interacts with the immune system, metabolism, nervous system, and production of biologically active compounds.

Researchers have proposed that glyphosate could potentially influence the microbiome and, in turn, affect pathways involved in neurological and immune function.¹

However, microbiome changes are also influenced by many other factors, including diet, medication, gastrointestinal health, inflammation, genetics and lifestyle.

Therefore, changes in the gut microbiome cannot be attributed to glyphosate alone.

Should parents be concerned about glyphosate?

The current evidence does not support the conclusion that glyphosate causes autism or ADHD.

At the same time, reducing unnecessary environmental exposures is a reasonable part of a broader approach to environmental health, particularly during pregnancy and childhood.

Practical steps may include:

• Choose minimally processed foods
• A diet rich in vegetables, fruits, legumes, whole grains, protein, and healthy fats provides important nutrients for healthy development.
• Wash produce
• Wash fruits and vegetables thoroughly under running water before eating them.
• Reduce unnecessary pesticide use
• Where practical, consider non-chemical approaches for household weed and pest control.
• Consider occupational exposure

People who work with pesticides may have higher levels of exposure. Following workplace safety recommendations and preventing residues from being brought into the home can help reduce household exposure.

Focus on the bigger picture

Environmental health is rarely about one chemical or one exposure.

When evaluating a child’s health, it can be useful to consider the broader picture, including nutrition, sleep, gastrointestinal health, environmental exposures, development, genetics, and other medical factors.

Can glyphosate be tested?

Glyphosate and AMPA can be measured in urine.

However, urine testing generally reflects recent exposure rather than a long-term measure of total exposure. A single result therefore cannot determine whether glyphosate has contributed to a child’s symptoms or developmental concerns.⁵

Testing should be interpreted within the context of an individual’s exposure history and overall health rather than in isolation.

The Bottom Line

Research into glyphosate, autism, ADHD, and childhood behavioural disorders is ongoing.

Some studies suggest that pesticide exposure may influence biological pathways relevant to neurodevelopment, while other human research –including recent Canadian research, has not found significant associations between prenatal glyphosate exposure and children’s cognitive or behavioural development.

A simple and practical way to reduce pesticide exposure is to use the “Dirty Dozen, Clean 15” created by The Environmental Working Group to help guide produce choices.  This can be found at www.ewg.org. 

At this point, the evidence does not establish that glyphosate causes autism or behavioural disorders.

A balanced environmental health approach is to reduce unnecessary exposures where practical while also considering the many genetic, nutritional, developmental, and environmental factors that can influence a child’s health.

If your child is experiencing behavioural, cognitive, developmental, or gastrointestinal concerns, a comprehensive assessment can help identify potentially modifiable factors and determine what further evaluation may be appropriate.

References

1. Barnett JA, Bandy ML, Gibson DL. Is the use of glyphosate in modern agriculture resulting in increased neuropsychiatric conditions through modulation of the gut-brain-microbiome axis? Front Nutr. 2022;9:827384.
2. Wang X, Lu Q, Guo J, et al. Oxidative stress and metabolism: a mechanistic insight for glyphosate toxicology. Annu Rev Pharmacol Toxicol. 2022;62:617-639.
3. de Oliveira MAL, Rojas VCT, de Sá JC, et al. Perinatal exposure to glyphosate-based herbicides induced neurodevelopmental behavior impairments and increased oxidative stress in offspring. Int J Dev Neurosci. 2022;82(6):528-538.
4. von Ehrenstein OS, Ling C, Cui X, et al. Prenatal and infant exposure to ambient pesticides and autism spectrum disorder in children: population based case-control study. BMJ. 2019;364:l962.
5. Hall M, Ashley-Martin J, Till C, et al. Associations of prenatal glyphosate exposure with child neurodevelopment in a Canadian pregnancy cohort study. Environ Int. 2025;199:109480.
6. Wang Y, et al. Maternal exposure to pesticides and autism or attention-deficit/hyperactivity disorders in offspring: a meta-analysis. Environ Sci Pollut Res Int. 2022.