A new study suggests a widely used weed killer may harm male fertility even at doses regulators consider safe, and that a common supplement could help blunt the damage.
The study published in Naunyn-Schmiedeberg’s Archives of Pharmacology found that glyphosate-based herbicide, marketed commonly as Roundup, caused significant testicular and sperm toxicity in adult male mice, while coenzyme Q10 (CoQ10) substantially reduced many of those effects.
Researchers exposed forty-two adult male ICR mice to daily oral doses of glyphosate, CoQ10, both substances together, or a control treatment for thirty-five days, the length of a full spermatogenesis cycle. Although the glyphosate dose used in the experiment was below “no-observed adverse effect levels” set by regulators in the United States, Europe, and Japan, the herbicide still severely disrupted reproductive health across multiple biological systems.
According to the study, mice exposed to glyphosate alone experienced a nearly 49% loss in absolute testicular weight, a sharp 43% decline in sperm concentration, a near doubling of abnormal sperm morphology, and a fourfold surge in mitochondrial reactive oxygen species.
Histological analysis showed widespread damage to the structures responsible for sperm production, with lesions and thinning of gonad cells. Hormonal balance also shifted, including significant drops in testosterone levels.
The authors attributed much of this damage to elevated oxidative stress, inflammation, and apoptosis (cell death) in testicular tissue. Glyphosate exposure suppressed antioxidant signaling pathways while activating an inflammatory cascade. Markers of oxidative stress spiked significantly.
CoQ10 co-treatment, however, mitigated many of these effects.
The antioxidant restored testicular weight to within 3.4% of control levels, improved histopathology, boosted cellular proliferation markers, reduced oxidative stress, and normalized key molecular pathways. Sperm concentration, motility, membrane integrity, and viability all improved, while testosterone levels returned to near-normal.
The authors emphasized that CoQ10 did not fully reverse every parameter but substantially mitigated glyphosate’s reproductive toxicity.
They also noted that the protective effects were observed despite CoQ10’s relatively low bioavailability when it was dissolved in an oil administered to the mice.
Still, the study had limitations, which were recognized by the authors. The study lasted only one spermatogenic cycle and therefore could not examine longer-term fertility matters such as mating outcomes and transgenerational effects. “Future research should examine the long-term and transgenerational reproductive effects of GBH exposure,” the authors wrote.
The researchers stressed that the study focused on adult male mice and did not examine other ages, strains, or females. They noted that while the findings highlight potential risks from glyphosate-based herbicides and possible benefits of antioxidants like CoQ10, the results cannot be directly extrapolated to humans without further research.
The study adds to a growing body of literature examining potential reproductive effects of glyphosate, one of the most heavily used herbicides worldwide. The authors called for future studies to more clearly define the implications for public health.
Glyphosate has become a focus of public health concern in recent years. The EPA website states there are “[no] risks of concern to human health from current uses of glyphosate.”
Yet, the chemical has been repeatedly cited as the cancer-causing agent in lawsuits against RoundUp’s makers.
A DrugWatch timeline of lawsuits reveals that RoundUp’s manufacturer, Monsanto, and others have been paying out billions of dollars in settlements for hundreds of thousands of cases of non-Hodgkin lymphoma, with a $2 billion judgment issued by a Court in Georgia earlier this year.
The World Health Organization has designated glyphosate as a carcinogen for almost a decade.
Some researchers have begun pointing to glyphosate and RoundUp Ready Corn, a genetically modified form of corn that better tolerates the herbicide, as the cause of the apparent increase in gut issues such as gluten intolerance, although this matter is still hotly debated in scientific and agricultural spheres.
CoQ10 is a common supplement available in various forms at grocery stores and pharmacies.