Smartwatches that measure blood glucose? Scam with phantom sensors and false data

Buying a smartwatch to monitor your health is a common habit, but if the promises involve medical functions such as needle-free blood glucose measurement, the risk of a scam is very high.

A report from the Federal Network Agency in Germany has caused a stir: checks carried out in 2025 revealed a large number of electronic devices sold in Europe that do not meet minimum safety requirements. The most alarming part? Many of these devices misrepresent their capabilities in the ‘medical’ field, posing a high risk to users.

Smartwatches and Blood Glucose: the danger of phantom sensors in the new European tests

The German investigation examined about 7.7 million electronic products, finding irregularities in a large share of the market. In physical stores, as much as 58% of the device models tested were rejected for not complying with the regulations, a figure that concerns around 1.9 million units.

Many issues are formal, such as the lack of the CE mark or instructions in the local language, but the most troubling part concerns smartwatches that simulate monitoring of blood sugar levels in the blood.

These gadgets, often sold online at rock-bottom prices, claim to measure blood glucose using sensors that technically have nothing to do with this function, or display purely random values based on statistical estimates, passing them off as real and reliable data.

The danger is medical in nature: currently there is no smartwatch capable of accurately measuring glucose autonomously and non-invasively.

To do so, a blood test or a certified subcutaneous sensor (CGM) is required. Relying on the skewed data from a cheap watch can push a person with diabetes toward disastrous decisions, such as delaying an insulin dose or ignoring the symptoms of a glycemic crisis because the device’s screen says everything is fine.

A test of the Kospet iHeal 6 model, for example, showed variations so large relative to reality that they could dangerously affect medication management.

The scale of the fraud has driven authorities to an unprecedented crackdown. In the last year alone, customs authorities blocked at the border over 359,000 suspected devices, examining thousands of shipments destined for the European market. In parallel, more than 1,200 listings were removed from e-commerce sites, relating to about five million potentially dangerous products.

The message from European checks is clear: if a smartwatch promises to measure blood glucose without needles and is sold at a ridiculously low price, it almost certainly is lying. Technology is making important strides in health, but we have not yet reached a point where a wrist sensor can replace true medical instruments and examinations.