Withings' urine-analyzing U-Scan device will tell you things your smartwatch can't; here's how it works and if you need one

Render of the Withings U-Scan Calci device next to an iPhone with the Withings app showing a Calcium widget.

What you need to know

• The Withings U-Scan Nutrio is the "first toilet plug-in urine scanner," measuring your body's health via urinary biomarkers.
• Tracked stats include Urinary pH to judge your diet, HydroStatus, fat metabolism, and Vitamin C levels.
• An alternate version called U-Scan Calci will focus on calcium levels to detect kidney stones, as well as other stats.
• The U-Scan starts at $379, requires cartridge replacements every three months, and only works for one user at a time.