Explainer
Microplastics urine test: what the research shows
We are focused on testing water today, and we are exploring how to make the method work for urine. Some people have already tried the current kit with urine and reported particles that appeared to be indicated microplastics. Here's what we know, what we are still working on, and how you can contribute.
What the research found
Urine is a newer frontier than blood or stool, but the evidence is arriving. In 2024, researchers reported microplastics in human urine and kidney tissue using micro-Raman spectroscopy. In 2025, a separate group quantified micro- and nanoplastics in the urine of volunteers using double-shot pyrolysis GC/MS, identifying common consumer polymers — PET, polypropylene, polyethylene, polystyrene.
These are small studies with specialized instruments. They establish that microplastics can be detected in urine — they do not establish a normal range or a health meaning. The research is young.
Note the size: particles found in urine may be much smaller than the particles this kit can visibly identify. The kit is designed to show particles around 10 µm and larger in water, so it cannot capture the full range of particles that researchers may find in urine. Why nanoplastics are the fraction that reaches the body.
Why urine is harder to test
Urine contains fats, proteins, cells, and other material that can bind to Nile Red and fluoresce. That means false positives are likely to be more common than they are in water. A stronger digestion step may help remove some of that interference, but the chemicals involved are not currently something we ship in a consumer kit because of shipping and safety constraints. Developing a practical urine protocol is part of what we are working on.
Want to try it?
Try it. We'd love to hear what you find. If you use the current kit with urine, please share your images and observations through our contact form.
These experiments help us understand what works and what needs to change as we develop a urine protocol. The current method has not been validated for urine, and urine can produce more background material than water, so treat each result as an early observation. It is not a medical result.
Try it and report back
We are working on urine. If you experiment with the current kit, please share what you learn with us.
Frequently asked
Can you test urine for microplastics?
Researchers have detected and quantified microplastic particles in human urine using specialized laboratory methods. We are focused on water today, but we are actively exploring how to make our test work with urine. Some people have already experimented with the water kit and reported particles that appeared to be indicated microplastics. If you try it, we would like to hear what you find.
Why test urine instead of blood?
Urine is easy to collect, which makes it a practical sample for research. It can also contain material the body has filtered and excreted, making it scientifically interesting. There is no established 'normal' range for particles in urine and no accepted health interpretation.
Can I try the water kit with urine?
Yes. People are experimenting with the water kit, and some have reported particles that appeared to be indicated microplastics. The kit is currently designed for water, so urine results are exploratory. Nile Red can bind to fats, proteins, cells, and other non-plastic material in urine, which can make false positives more likely. If you try it, please report back and share what you find.
What does a urine microplastics result mean?
It tells you that particles in your sample bound to the Nile Red dye and fluoresced — which includes most plastics, and also some non-plastic hydrophobic material. It does not tell you a body burden or anything about your health. It is best understood as a visualization experiment.
Related: microplastics in stool · microplastics blood tests, explained
Any urine result is preliminary and exploratory. This is not a diagnostic tool and cannot measure total exposure, determine whether microplastics are affecting your health, or diagnose or rule out any medical condition.