Continuous glucose, cardiac monitoring, epilepsy alerts, oxygen. What's clinically validated, what's wellness, and what a clinician will actually accept data from.
A device is either cleared by a regulator for a stated medical purpose, or it is a wellness product. The hardware can be near-identical. What differs is what the manufacturer is permitted to claim, what evidence sat behind it, and whether a clinician can act on the reading. "Medical grade" is a marketing phrase; the clearance is the fact.
The short version: you can now buy a CGM without a prescription — but the over-the-counter versions are cleared for different purposes, and one of them is explicitly not for managing diabetes.
The FDA cleared the first over-the-counter CGM, Dexcom's Stelo, in March 2024. Abbott's Lingo and Libre Rio followed in June 2024. As of mid-2026 Stelo and Lingo are the two available in the US; Libre Rio has clearance but no announced launch.
The practical consequence: two sensors that look the same and sit on the same arm can carry completely different permissions. If insulin dosing is involved, an OTC wellness sensor is the wrong product — that's a prescription CGM decision made with a clinician.
The short version: pulse oximeters are less accurate on darker skin, the effect is well documented, and the FDA moved in 2025 to tighten testing. If you're relying on oxygen readings, know this before you trust a number.
Melanin absorbs the red and infrared wavelengths pulse oximetry depends on, which biases readings. The clinical consequence is occult hypoxemia — oxygen genuinely low while the device reads acceptably. Among patients showing SpO2 of 92–96%, Black patients were found to have roughly three times the frequency of occult hypoxemia compared with White patients.
In January 2025 the FDA issued draft guidance to improve accuracy across skin pigmentations for oximeters used medically. It proposes substantially stricter validation:
This guidance addresses oximeters used for medical purposes. The SpO2 feature on a general-purpose smartwatch is typically a wellness feature and sits outside it entirely — so the accuracy concern applies at least as much, with less oversight.
Consumer wearable data is rarely admitted directly into a clinical record. What it does well is prompt a conversation — a watch flagging an irregular rhythm leads to a proper ECG, which is the thing that gets acted on. Treat the wearable as the reason to make an appointment, not as the result. If you intend the data to inform treatment, ask the clinician beforehand what form they can use.
The short version: seizure alerts, cardiac alerts and similar are only as good as the response behind them. The sensor is the easy part.
Assessments for this segment will state each device's regulatory status and indication in plain language, alongside documented accuracy limits, alerting behaviour, data handling, certification status and published SAR figures. The weekly brief is where they land first.
Not a test laboratory. ViaMondo does not measure SAR, RF emissions or any other physical property of a device, and makes no independent measurement claims. Figures we publish are taken from manufacturers' published data and public regulatory filings, cited to source.
Not medical advice. This page is general and educational. Nothing here diagnoses, treats, prevents or cures any condition, and no device described replaces clinical care. Do not change medication, insulin dosing or treatment based on a wearable reading. Always consult a qualified healthcare professional about your own situation or that of someone you care for.