Two Doors for a Wearable: Wellness Claim or 510(k)

Two doors, and the one that moved in January

A startup building a ring, a wristband or an earbud with an optical sensor has always had two ways into the US market. Door one is a general wellness claim: the product tracks sleep, activity, recovery, and the FDA does not intend to regulate it as a medical device. Door two is a 510(k): one function is a medical device, with a predicate, performance testing and a clearance letter. What changed in 2026 is where door one is.

On January 6, 2026 the FDA reissued its General Wellness: Policy for Low Risk Devices guidance, replacing the 2019 version. The new text says the agency may consider products that use non-invasive sensing (optical sensing is the example given) to estimate, infer or output physiologic parameters such as blood pressure, oxygen saturation, blood glucose and heart rate variability to be general wellness products. That sentence did not exist before. Under the 2019 policy, a blood pressure number on a consumer wristband was a hard conversation.

The sentence comes with six conditions, and they are the whole article. The product must be non-invasive and not implanted. It must not use a technology that is risky without regulatory controls. It must not be intended to diagnose, cure, mitigate, prevent or treat a disease or condition. It must not substitute for an FDA-authorized device. Its claims, functionality and outputs must not prompt or guide specific clinical action. And it must not show values that mimic clinical values unless those values are validated, by manufacturer testing or peer-reviewed literature. The guidance is nonbinding, and it describes the FDA’s enforcement intent, not a classification. But it is the clearest line the agency has drawn for this product category.

What the wellness door asks of the product

Read the conditions as a product spec and the picture is specific. The device may display values, ranges, trends, baselines and longitudinal summaries, and may put them in the context of sleep, activity, stress or recovery. It may tell the user that seeing a healthcare professional might be helpful when an output falls outside a wellness range, as long as the notification does not name a disease, does not call the value abnormal or diagnostic, does not contain a clinical threshold, and does not turn into ongoing alerts.

The guidance also lists what takes a product out of the policy, and the list covers labeling, advertising, user interface and functionality together: references to specific diseases, clinical conditions or diagnostic thresholds; alerts or prompts that recommend clinical action; treatment guidance; claims of clinical equivalence, clinical accuracy, medical grade or substitution for a cleared device; and intended-use statements that target diagnosis, screening or monitoring of a condition. A marketing page can close the door as surely as a firmware feature can.

Two boundaries matter for hardware teams in particular. The first is invasiveness: the guidance’s own example of a microneedle glucose wearable fails on that point alone, however careful the claim. The second is the technology itself: a laser product that claims to rejuvenate skin is named as not low risk because of burn risks to skin and eyes, even though the claim is a wellness claim. A laser skin device sits outside the wellness policy on the technology alone, whatever the claim says. And the guidance’s own wearable example, a wristband that measures sleep by accelerometer and pulse rate and blood pressure by photoplethysmography, qualifies as a wellness product provided it has validated values for blood pressure. The sensor is not the problem. The evidence behind the number is.

Whoop: the door closed, then reopened by a changed product and a changed policy

The Whoop case shows both doors in one product. On July 14, 2025 the FDA sent Whoop a warning letter over Blood Pressure Insights, a feature that gave members daily systolic and diastolic estimates. The agency’s position was that a feature estimating blood pressure has the same intended use as a blood pressure measurement device, which is a device that needs clearance, and that the wellness policy did not cover it. The letter cited the website copy, which described the insights as medical-grade, the feature’s design, a gauge with green, yellow and orange zones marking a target range, and the firm’s earlier responses to FDA inquiries.

On June 17, 2026 the FDA issued a close-out letter. Whoop had modified the product and its labeling, and, consistent with the updated wellness guidance, the agency said it does not intend to enforce the device requirements for the feature as modified. The letter is explicit that it covers only that feature, as modified, and nothing else. The close-out does not say what changed; the FDA’s public record is the warning letter, the January policy and the close-out.

The lesson for a product team is not about Whoop. It is that the claims, the interface and the marketing copy were read as evidence of intended use, and that the January policy was the other half of the reopening. Those strings and screens deserve the same change control as firmware: a version, an owner, a review before release. We have written before about where OEM responsibility sits in the contract; claims and labeling belong on that list, with a named owner on the brand side and a rule that the factory does not ship a carton or a splash screen that has not been through that review.

The other door is getting busier, one feature at a time

The 510(k) door has not emptied out because the wellness door widened. It has become more surgical. Between September 2025 and October 2026 the FDA’s 510(k) database shows a run of clearances attached to consumer wearables: Apple’s Hypertension Notification Feature (K250507, September 11, 2025), Samsung’s Sleep Apnea Feature version 2.0 (K261011, July 20, 2026) and Hearing Aid Feature (K261187, July 31, 2026), Happy Health’s blood pressure monitor (K254000, September 3, 2026), and Shenzhen Ninenovo’s blood oxygen ring (K260490, October 2, 2026). All are traditional 510(k)s found substantially equivalent.

Look at what was cleared. For Apple and Samsung it was not a watch or an earbud but a feature: software that analyzes data from the consumer product’s existing sensors, while the watch and the earbuds stay consumer products. The two smaller companies took the other route. Ninenovo cleared the ring itself, as an oximeter. Happy Health cleared blood pressure software that runs on a ring it had already cleared as a monitoring system. Two routes, and both are narrow: the cleared thing is defined tightly enough to be verified, and changed later, on its own. That is the architecture decision a startup should make early. The cleared function needs a defined boundary: which sensor data it consumes, its own algorithm version, its own verification record and its own labeling, so that it can go through review, and be changed later, without the entire bill of materials coming along. A product where the wellness features and the cleared feature share one undifferentiated firmware image turns every cosmetic update into a documented change assessment.

Which door is right is the brand’s decision, with its regulatory counsel. Our point is narrower: the two doors ask for different builds, and the difference shows up before tooling, not after launch. In our DFX risk review we rate 33 items red, yellow or green before any product goes to tooling. For a sensing wearable, the door is the item we would put at the top of that list, because most of the others depend on it.

What each door asks of the build

Door one, wellness, still needs validation evidence. The policy’s own condition is validated values. That means a protocol, a reference method, a defined population and a record you can show, produced during development, not assembled after a letter arrives. The guidance mentions manufacturer testing and peer-reviewed literature as routes; it does not prescribe a method, so the brand and the factory have to agree on one and document why it is adequate. If the number on the screen cannot be traced to a test report, the door is not really open.

Door two, 510(k), needs a carve-out. Design the cleared feature as a module: the sensor data it consumes, the algorithm, the output and the labeling, with its own requirements, its own verification and its own change history. Keep the consumer features outside the module’s boundary. For a home-use device the electrical safety and usability work does not go away either; we covered that side in our home-use medical device guide. The module boundary is what lets the brand update a watch face without re-verifying a cleared algorithm.

Either door, treat claims as a controlled document. The guidance puts labeling, advertising, the user interface and functionality on the same list, and in practice that covers interface strings, app store copy, packaging and the web page. A phrase like “clinical accuracy” or a disease name on a landing page can change the intended use. Put those strings under revision control with the firmware, and make the release checklist ask whether any of them changed.

On scope: we design and build under ISO 13485:2016 and provide documentation and testing support for the brand’s regulatory work. Deciding which door a product uses, the submission, and the claims made to users belong to the legal manufacturer, typically the brand. What we can do is make sure that, whichever door is chosen, the verification data, the module boundaries and the controlled labeling exist by the time the first production unit ships. If you are planning a sensing wearable, send an inquiry and ask us how we would structure the test plan for each door. You’ll have an initial response within two business days.

FAQ

Does the January 2026 policy mean a blood pressure wearable no longer needs a 510(k)?

Not by itself. The guidance says the FDA may consider such a product a general wellness product when the outputs are intended solely for wellness, the product is non-invasive, it makes no clinical claims, it does not prompt clinical action, and its values are validated. A product that estimates blood pressure for medical purposes, or whose labeling or interface implies that, is still a device. The policy is nonbinding and describes enforcement intent, not a classification.

What counts as “validated values”?

The guidance names manufacturer testing and peer-reviewed clinical literature as ways to validate, and does not prescribe a protocol. In practice that means a documented validation study against a reference method, with the population, conditions and acceptance criteria written down before the test. The brand decides the approach; the factory’s job is to supply production-representative units, support the testing and keep the records.

Can a contract manufacturer decide which door a product uses?

No. Intended use, claims and the regulatory submission belong to the legal manufacturer. A contract manufacturer contributes the engineering that makes either door workable: support for the validation testing, the module boundary around a cleared feature, the design history and the production records. Agree in writing who owns which part before development starts.

What happens if marketing adds a disease claim after launch?

Under the guidance, labeling includes instructions, user-facing claims, promotional materials and marketing communications, and the FDA expects all of it to stay within the stated intended use. A later claim can move a product from one door to the other. The Whoop sequence runs the other way: a warning letter in July 2025 over a feature as launched, then a close-out in June 2026 after the product and labeling were changed and the policy moved. Claims move a product across the line in both directions.