Glyphosate’s novel liver toxicity, particularly its impact on circadian rhythm disruption at real-world exposure levels, is the focus of a groundbreaking study by Xiao et al. (2025), published in Food and Chemical Toxicology.
This research reveals that glyphosate exposure in mice disrupts the hepatic circadian clock system, significantly impairing glucose and lipid metabolism in the liver. It uncovers a previously unknown mechanism of glyphosate toxicity that may be relevant to environmental and dietary exposure in humans.
These findings highlight the potential for chronic low-level glyphosate exposure to contribute to metabolic disorders, raising urgent questions about the long-term health impacts of the world’s most widely used herbicide.
Study methodology
The study adopted a comprehensive approach combining in vitro and in vivo experiments. For the in vitro analysis, murine hepatocytes (AML12 cells) were exposed to 0.1 mM glyphosate, a concentration determined through viability and apoptosis assays to avoid cytotoxicity while eliciting metabolic changes. Cells were synchronised using forskolin before exposure, allowing circadian rhythm analysis.
In the in vivo experiment, male Institute of Cancer Research (ICR) wild-type mice received 0.5% glyphosate in drinking water over eight weeks, approximating real-world agricultural exposure. Researchers assessed locomotor activity, glucose tolerance, and insulin sensitivity, collecting liver tissues at six intervals across 24 hours to examine circadian gene expression and metabolic indicators.
Major outcomes
The study by Xiao et al. (2025) found that glyphosate exposure led to significant circadian rhythm disruption and metabolic dysfunction. At the molecular level, glyphosate altered the expression of core circadian clock genes (Bmal1, Nr1d1, and Dbp) in hepatic tissue, inducing phase delays of 1.5–2.66 hours and reducing NR1D1 protein levels by up to 40%. These disruptions were coupled with suppressed expression of vital metabolic genes – Hmgcr (cholesterol synthesis, reduced by 35%), Glut2 (glucose transport, reduced by 28%), and Fasn (fatty acid synthesis, reduced by 22%).
These molecular alterations translated into physical metabolic effects, such as a 42% reduction in hepatic glycogen reserves at ZT20 and a 31% decrease in total liver cholesterol.
Behaviourally, glyphosate-exposed mice exhibited photophase-specific hyperactivity, with a 27% increase in daytime movement and a prolonged circadian period from 23.7 to 24.3 hours. Metabolic testing revealed impaired glucose tolerance, marked by an 18% rise in blood glucose 15 minutes post-challenge, and a 15% reduction in insulin sensitivity at 90 minutes.
Mechanistic analysis confirmed the role of the BMAL1 pathway, as Bmal1 knockout nullified glyphosate’s metabolic effects and prevented additive suppression of Hmgcr and Glut2 in KO cells, confirming this pathway’s role in glyphosate-induced metabolic disruption.
Together, these findings demonstrate glyphosate’s multi-layered biological impact, from gene expression alterations to whole-body physiological changes. The consistency of circadian delay and metabolic suppression supports the hypothesis that chronic exposure could result in long-term metabolic consequences.
Implications for human health
The findings from the Department of Clinical Veterinary Medicine, Northwest A&F University (Yangling, Shaanxi, China), carry major implications for public health. Glyphosate residues are commonly found in food crops (Chang et al., 2023), and biomonitoring studies have detected glyphosate in human urine at concentrations as high as 73.5 µg/L in occupationally exposed individuals (Gillezeau et al., 2019).
Given the liver’s role as a metabolic and circadian regulator, chronic glyphosate exposure could contribute to insulin resistance, non-alcoholic fatty liver disease (NAFLD), and dyslipidaemia – conditions previously associated with circadian disruption in epidemiological studies (Poggiogalle et al., 2018). The study’s environmentally relevant dose enhances its translational value, although human-specific causal links remain to be confirmed through further research.
Study’s conclusion
This rigorous investigation shows that glyphosate exposure disrupts hepatic circadian rhythms and impairs metabolic homeostasis via interconnected molecular pathways. The documented phase delays (1.5–2.66 hours) in clock gene expression and suppression of metabolic genes (Hmgcr, Glut2, Fasn) establish a mechanistic link between circadian misalignment and metabolic dysfunction.
These changes were observed at exposure levels consistent with real-world agricultural contexts (0.5% in drinking water), rather than at extreme toxicological doses.
The study presents several critical insights:
- glyphosate’s metabolic effects are BMAL1-dependent, indicating a specific circadian pathway of toxicity;
- the consistency between cellular and whole-animal responses supports the plausibility of similar outcomes in humans,
- the metabolic impairments observed – such as reduced glycogen and cholesterol – are clinically relevant to metabolic diseases including diabetes and NAFLD.
Glyphosate, CAR activation and nonalcoholic fatty liver disease
Increased circulating lipid levels and metabolic alterations in fatty acid utilization and intracellular signaling have been related to insulin resistance in muscle and liver. In the liver, there are several pathways that determine the onset of insulin resistance (Yazıcı and Sezer; 2017). Mitochondrial dysfunction and endoplasmic reticulum stress, through increased oxidative stress, also plays a role in the pathogenesis of insulin resistance, especially in nonalcoholic fatty liver disease.
In a recent published article (De Battistis F et al., 2025), the possible involvement of Constitutive Androstane Receptor (CAR) in the development of NAFLD is highlighted. Indeed, the authors state “Experimental and epidemiological data suggest that endocrine disruptors, especially pesticides, play a significant role in NAFLD’s development and progression via CAR-regulated pathways”.
Glyphosate could also be an activator of CARs, such as PFOA, PBDE, fungicides and other pesticides, causing NAFLD.
Glyphosate toxicity: new compelling evidence
These results contribute to a growing body of evidence that challenges the established safety profile of glyphosate, especially regarding its endocrine and metabolic effects. The identification of circadian rhythm disruption as a novel toxicity mechanism calls for a re-evaluation of current risk assessment frameworks.
Future research should address whether these effects are reversible post-exposure and explore strategies for mitigating risk via circadian rhythm support or lifestyle interventions.
From a regulatory standpoint, the study recommends:
- broader assessment of glyphosate’s chronotoxicity;
- consideration of cumulative effects from low-dose, long-term exposure;
- development of biomarkers for circadian disruption in exposed populations.
Overall, this study presents compelling evidence that glyphosate’s toxicity extends beyond traditional toxicological endpoints, encompassing chronic disruption of biological timing systems with potentially serious implications for metabolic health and public safety.
Dario Dongo
Cover credit: Xiao et al., 2025
References
- Chang, V. C., Andreotti, G., Ospina, M., Parks, C. G., Liu, D., Shearer, J. J., … & Hofmann, J. N. (2023). Glyphosate exposure and urinary oxidative stress biomarkers in the Agricultural Health Study. Journal of the National Cancer Institute, 115(4), 394–404. https://doi.org/10.1093/jnci/djac242
- Gillezeau, C., van Gerwen, M., Shaffer, R. M., Rana, I., Zhang, L., Sheppard, L., & Taioli, E. (2019). The evidence of human exposure to glyphosate: A review. Environmental Health, 18(1), 2. https://doi.org/10.1186/s12940-018-0435-5
- Poggiogalle, E., Jamshed, H., & Peterson, C. M. (2018). Circadian regulation of glucose, lipid, and energy metabolism in humans. Metabolism, 84, 11–27. https://doi.org/10.1016/j.metabol.2017.11.017
- Xiao, B., Jiang, H., Dong, H., Li, C., Zhang, H., Gao, D., Wang, A., Jin, Y., & Chen, H. (2025). Glyphosate exposure impairs glucose and lipid metabolism by disturbing the circadian clock system in mice liver. Food and Chemical Toxicology, 115436. https://doi.org/10.1016/j.fct.2025.115436
- De Battistis F, Djordjevic AB, Saso L and Mantovani A (2025) Constitutive androstane receptor, liver pathophysiology and chemical contaminants: current evidence and perspectives. Front. Endocrinol. 16:1472563. doi: 10.3389/fendo.2025.1472563.
- Yazıcı D, Sezer H. Insulin Resistance, Obesity and Lipotoxicity. Adv Exp Med Biol. 2017;960:277-304. doi: 10.1007/978-3-319-48382-5_12. PMID: 28585204
Dario Dongo, lawyer and journalist, PhD in international food law, founder of WIISE (FARE - GIFT - Food Times) and Égalité.
