Review · 6 min read

Withings Sleep Rx: Sleep Tracking Data and Specifications

Withings Sleep Rx review built from Withings' published clinical validation summary and product information. Under-mattress mat with FDA 510(k) K231667 clearance for OSA diagnosis.

Summary of Findings · 2021

Evidence summary: Withings Sleep Rx

1 outcome has measured evidence in the CircaTest corpus, drawn from 1 peer-reviewed study totaling 118 participants. Each card below answers one buyer question and shows the most representative finding. Hover any certainty badge for the verbatim GRADE definition. The full per-study breakdown is in the Sources panel below.

Outcome 01 of 01

High

Sleep vs wake detection

How well does the device know whether you're asleep or awake?

Agreement

SUBSTANTIAL

Best evidence

88%

From Edouard et al., 2021 (n = 118)

Sensitivity for detecting AHI ≥ 15 events/h (moderate-severe sleep apnea).

Each card answers one buyer question. The bold AGREEMENT label maps the underlying statistic to a normalized rubric (Landis & Koch 1977 cutoffs for kappa, standard percent thresholds for accuracy and per-stage agreement) so cards from different devices can be compared at a glance. The GRADE certainty rating is computed across all contributing studies for that outcome, not just the representative one shown. Methodology →

Audit · sources & method1 study · 118 participants · 2026-04-06

Every quantitative claim above traces back to one of the studies listed here. Click any study identifier to verify against the primary source. CircaTest does not own or modify any of these studies; we link out so you can audit the original.

Validation of the Withings Sleep Analyzer, an under-the-mattress device for the detection of moderate-severe sleep apnea syndrome
Edouard P et al. · Journal of Clinical Sleep Medicine · 2021
n = 118 · adult; suspected obstructive sleep apnea · clinical · vs polysomnography
PMID 33590821 PMC8314651 DOI 10.5664/jcsm.9168
Tested in this study as: Withings Sleep Analyzer
Reported metrics for Withings Sleep Rx:
- Sensitivity: 88%Sensitivity for detecting AHI ≥ 15 events/h (moderate-severe sleep apnea).
- Specificity: 88.6%Specificity for detecting AHI ≥ 15 events/h.
- Accuracy: 92.6%AUROC = 0.926 at AHI ≥ 15 threshold (recorded as percent for display; the underlying metric is AUROC, not raw accuracy).
- Sensitivity: 86%Sensitivity at the higher AHI ≥ 30 threshold (severe sleep apnea).
- Specificity: 91.2%Specificity at AHI ≥ 30 threshold.
CircaTest note: The canonical peer-reviewed validation of the Withings Sleep Analyzer for sleep apnea detection. Published in JCSM. The 88% sensitivity / 88.6% specificity figures (AHI ≥ 15) are the basis for the FDA 510(k) clearance Withings later received for the Sleep Rx variant. CircaTest cites this as the primary evidence for any Withings nearable apnea claim.
Full study record on CircaTest →

Sources retrieved from PubMed, Europe PMC, and publisher pages. Abstracts shown on individual study records are reproduced under public-domain or fair-use license per their source. Identifiers above link to the original primary source. CircaTest is the curatorial layer; we do not modify the underlying studies.

Data Sources and Methodology

This review compiles data from Withings' published Sleep Analyzer and Sleep Rx product information (withings.com, verified April 6, 2026), Withings' published clinical validation summary, and the FDA 510(k) database. No first-person testing was conducted.

Important context: the non-prescription Withings Sleep Analyzer mat preceded the FDA-cleared Sleep Rx. Both use the same general under-mattress sensor technology. Sleep Rx adds the FDA-cleared OSA diagnostic indication. The clearance was announced via Withings press release on September 9, 2024 and the device received FDA 510(k) K231667 in September 2024.

Sleep Apnea Detection (FDA-Cleared)

The underlying peer-reviewed validation is Edouard et al., 2021, which compared the Withings Sleep Analyzer under-mattress mat against simultaneous PSG in 118 adults and reported 88% sensitivity and 88.6% specificity for moderate-to-severe sleep apnea (AHI greater than or equal to 15). This is the basis of the FDA 510(k) K231667 clearance granted in September 2024 for the Sleep Rx variant.

Important caveat: the 88% / 88.6% figures are for sleep apnea detection, not for sleep stage classification accuracy. Edouard et al. and Withings do not report PSG-comparable per-stage accuracy figures. Verify the FDA 510(k) clearance scope against the FDA database before relying on it.

The non-Rx Sleep Analyzer variant detects breathing disturbances but is not FDA-cleared for diagnosis.

Sensor Suite

Per Withings' published product information, the Sleep Rx mat contains:

Pneumatic sensor: measures respiratory rate, heart rate via ballistocardiography, and body movement across the mattress.
Sound sensor: identifies snoring and breathing cessation events.

The device sits under the mattress; no wearable, wires, masks, or straps are required. There is no PPG, accelerometer, ECG, EDA, SpO2, temperature, altimeter, or GPS sensor.

Sleep Tracking Features

According to Withings' product documentation, the Sleep Rx detects light, deep, and REM sleep, produces a sleep score, and exposes full staging data without an additional subscription. Nap detection and a smart alarm feature are not documented for this device. CircaTest has not separately extracted total-sleep-time deviation figures.

Health Features

Resting heart rate: tracked via ballistocardiography.
Respiratory rate: tracked via the pneumatic sensor.
Sleep apnea detection: FDA-cleared on the Sleep Rx variant under K231667 (88% sensitivity, 88.6% specificity per Withings published validation summary).
HRV, blood oxygen, body temperature, menstrual cycle, stress, readiness, strain, recovery: not included.

Hardware

Form factor: under-mattress fabric mat.
Power: mains-powered via USB. Continuous operation, no charging cycle.
Weight and water resistance: not the relevant specifications for this form factor.
Display: none.

Subscription and Cost

Withings Sleep Rx is sold via medical channels (the prescription-cleared product) and standard consumer retail (the Sleep Analyzer non-Rx variant in some regions). CircaTest does not have a verified specific US consumer price for the Sleep Rx variant from a primary Withings source. There is no subscription required and full sleep staging is available on the free tier.

Compatibility

The Withings Sleep Rx pairs with both iOS and Android via the Withings Health Mate app, with Apple Health and Google Fit integrations. Strava is not supported.

Who It Is For (Based on the Data)

Users who want passive, no-wearable sleep tracking that does not require remembering to put on a device
Users specifically interested in the FDA-cleared sleep apnea screening indication on the Sleep Rx variant
Users who prefer a one-time hardware purchase with no subscription
Users who already trust the Withings ecosystem (smart scales, blood pressure monitors, ScanWatch)

The device's data profile is less aligned with users who want HRV or SpO2 data, users who want a portable tracker for travel, or users who require independent peer-reviewed PSG validation already imported into the CircaTest corpus.

Products Mentioned

Withings Sleep Rx (and Sleep Analyzer)

Under-mattress sleep mat. FDA 510(k) K231667 (September 2024) for the Sleep Rx variant. Withings published 88% sensitivity and 88.6% specificity for AHI greater than or equal to 15. The Amazon search link routes to the consumer Sleep Analyzer; the FDA-cleared Sleep Rx variant may require prescription distribution. CircaTest does not have a verified US consumer price for the Sleep Rx variant.

Not medical advice. This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. FDA 510(k) clearance for screening is not the same as a clinical diagnosis. If you have sleep concerns, consult a qualified healthcare provider.