I'm dehydrated. How do I know? Withings U-Scan told me so, and it's based on what may be the best source for this information: my own urine.

I know. Blech. But also, wow; home urine analysis in about the time it takes you to, well, use the bathroom.

I first learned about the Withings U-Scan home urine analysis system back in January at CES 2025. It sounded kind of incredible. The device could take the lab-style analysis that usually requires you to go to a doctor's office, pee into a cup, and hand it over to a lab technician who would then send it to a lab for analysis, and transform it into a compact system that fits in any toilet.

That's more or less what we got here, a $379.95 / £319 rechargeable device that does all of that in one... er... sitting.

It's not perfect. It might require that you change your bathroom habit, it uses replaceable cartridges that'll cost you $99.95 / £89.95 every three months, and it cannot yet, as was promised earlier this year, recognize different people's pee. Essentially, it's a urine analysis system for one and can only be activated through the Withings app on your phone.

Even so. I'm impressed.

Withings U-Scan Review: Design and setup

Withing's U-Scan is a large white puck that you press between your palms to twist and open so you can install the carousel of measurement tabs. There are a total of 44 of these tiny, chemically sensitive strips in each carousel. Every test takes two strips for a total of 22 urine tests. Most people will only test once a week. The circuit board and algorithm live inside U-Scan, so that all analysis is done there.

Twisting the device open and closed is not easy, but in some ways, this gives you confidence that it is fully water-tight.

When it's open, you set up your app and connect it via Bluetooth to the U-Scan by pressing a button on the inside. It also connects to your home network's Wi-Fi. This process is pretty painless, as is installing the carousel of test tabs. The app, by the way, can connect to Apple Health to gather all your relevant health data and to share Withings' insights with Apple Health.

U-Scan also ships with three sizes of toilet clips and guides you on which one to use based on your toilet's style. There's also a charge tank, which doubles as a bath to wash the device after the first three months of use (the charge is rated to last three months, too). It even ships with gloves so you don't have to touch a device you've spent the last three months peeing on.

U-Scan can, depending on which carousels you use, test for either nutrition or kidney health. In the latter, the system keeps track of calcium levels, an excess of which can lead to the development of painful kidney stones.

My test unit, though, arrived with the nutrition carousel, which looks at acidity, vitamin C, ketones, and hydrostatus.

Withings U-Scan: Getting started

Proper placement of the Withings U-Scan in your toilet is critical, and this is where I learned that, if I wanted to measure my urine, I'd have to sit down to pee.

You see, the puck and its attachment hanger are placed dead-center at the front of the toilet; the clip hangs over that front lip.

The smooth back of the U-Scan faces you and, if you pee on it, the other side is designed to capture and direct that pee into a reservoir that pulls the liquid inside.

Since the system does not know when it's being peed on, you have to first open the Withings App and then select measurement. After that, you have two minutes to pee.

I went through this process three times before I successfully got a reading. The first time, there was an unidentified error, and the second time, the system accused me of not peeing sufficiently. Fortunately, it didn't waste any test strips in either case.

Finally, I peed long enough to get a reading. I knew the system was doing its work because there are somewhat noisy motors that make the urine collection and the tiny internal lab work possible.

Within minutes, I had my first reading. If you don't see it, you can quickly sync your phone app to the device.

I was pleased to see that my pH or bio-acidity was "In Target", as were my vitamin C and ketone levels. The only thing that didn't look right was my hydrostatus, which came in low. When I opened that reading for details, the app told me, "Your hydration level is lower than optimal. Increase your water intake to reach a better balance."

Withings U-Scan: Verdict

As my wife said to me, somewhat sarcastically, when I told her about my reading, "Oh, good, I guess you don't have to go to the doctor."

I'd like to think that, but this is not an FDA-cleared device and is not intended as a medical substitute. Instead, it's a wellness product that gives you indicators but not the final word.

Still, it's nice to get some early warning signals on nutritional issues and, yes, I would love to avoid painful kidney stones in my lifetime.

I do not look forward to the cleaning process and think it's a shame that it's not yet useful for all the people peeing into that toilet in my home. Withings told me that the feature is coming, but did not provide a timeline.

The price is not terrible for what it does, but I'm not thrilled about paying another $99 every three months to check my urine. That's the one area that will likely give many people pause and may relegate this for use with people who really need frequent urine analysis. I'm probably not one of them.

Now, if you don't mind, I'm going to drink a big glass of water.

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