SiBio KS3 continuous ketone monitor
Last checked September 28, 2026
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| Type | Continuous ketone sensor |
|---|---|
| Maker | SiBio (Sibionics) |
| Measures | Ketones in the fluid under the skin (ketones only, no glucose) |
| Wear or use | 14 days per sensor, worn on the back of the upper arm; 1-hour warm-up |
| Readings | Every 5 minutes, sent to the phone over Bluetooth |
| App | SiBio CKM app (iOS and Android) |
| US status | Not FDA authorized. Sold by SiBio as a non-medical product |
| UK status | Sold on Amazon UK as not intended for medical purposes |
| EU status | SiBio’s shop describes it as CE certified; the maker says it is not for diagnosing, treating or monitoring disease |
| Price | €85.99 per 14-day sensor on SiBio’s shop; £74.99 on Amazon UK (checked 28 Sep 2026) |
| Running cost | £162.92 a month (Amazon UK price, one sensor every 14 days; see the cost calculator) |
| Availability | On sale now to adults 18+ (SiBio ships internationally; Amazon UK) |
| Where to buy | Amazon UK, SiBio shop (outside the UK) |
What it is
The KS3 is a ketone-only sensor from SiBio (part of Sibionics). A small flexible tip goes just under the skin on the back of the upper arm and reads ketones in the fluid there every 5 minutes for 14 days, after a 1-hour warm-up. It is water resistant to 1 meter for up to 1 hour (rated IP38) and sends readings to the SiBio CKM app (SiBio).
SiBio’s earlier model, the KS1, was listed on SiBio’s shop as available until sold out, and its Amazon UK listing showed as currently unavailable when we checked.
What it is not for
SiBio sells the KS3 to adults aged 18 and over and states that it is not intended for use in the diagnosis, treatment or monitoring of disease (SiBio). The Amazon UK listing says it is not for medical purposes and not a substitute for medical equipment (Amazon UK). It has no FDA authorization.
For people with type 1 diabetes, and others at risk of diabetic ketoacidosis (DKA), ketone levels are a medical matter. Follow the plan from your diabetes team and the guidance from the NHS or the American Diabetes Association. No consumer ketone sensor replaces the testing your care team asks for.
Price and running cost
- SiBio shop: €85.99 for one 14-day sensor; packs of 4 weeks €171.98, 8 weeks €343.96 and 14 weeks €601.93.
- Amazon UK: £74.99 for one sensor, sold by SIBIONICS and dispatched by Amazon (checked 28 September 2026).
- At the Amazon UK price, one sensor every 14 days works out at £162.92 a month, or about 26 sensors a year.
What research found
A small 2026 randomized trial used SiBio’s earlier KS1 sensor in 7 healthy volunteers taking ketone drinks or a placebo for 14 days. The sensor picked up the rise in ketones after the drinks, but readings drifted downward over the 14 days in both groups, which the authors put down to sensor drift. The study did not compare the sensor with finger-prick blood tests, and one sensor came off on day 4 (Kjær et al., 2026). More on accuracy.
Where to buy
In the UK: SiBio KS3 on Amazon UK. Elsewhere: SiBio’s own shop, which ships internationally and prices in euros.