Do microplastics end up in your urine after you eat or drink them?

What's actually in it

Every time you eat food that touched plastic packaging, drink from a plastic bottle, or eat seafood from polluted water, you consume microplastics. The smallest fragments pass through the gut lining into your bloodstream.

Your kidneys filter blood and produce urine. Anything small enough to travel in blood eventually reaches the kidneys, which is how microplastics wind up in urine.

What the research says

A 2026 study in Chemosphere focused on aromatic microplastic fragments, those derived from plastics like polystyrene and polyethylene terephthalate. Researchers found that these fragments concentrate during urinary excretion, meaning the kidneys are accumulating and filtering a higher concentration than what circulates in blood.

This matters because as plastic particles pass through kidney filtration structures, they can physically damage the delicate tubules and membranes. Aromatic plastics also carry chemical additives that are toxic to kidney cells and may disrupt urinary tract function.

The researchers noted that the urinary tract may be an underrecognized route of long-term plastic accumulation. People who regularly drink from plastic bottles and eat food in plastic packaging have consistently higher microplastic concentrations in urine than those who use glass and stainless steel.