Blood Pressure Ring 2026: Happy Ring vs Hilo vs a Cuff

Disclaimer: This article is for information only and is not medical advice. Cuffless blood pressure devices aren't a substitute for a validated cuff or for care from a clinician. Don't start, stop or change blood-pressure medication based on a wearable reading. If you're pregnant, have an irregular heartbeat such as atrial fibrillation, or take blood-pressure-affecting medication, talk to your clinician before relying on any cuffless reading. A very high reading with symptoms such as chest pain, shortness of breath, severe headache, or weakness or numbness needs urgent medical care. BiohackList may earn commissions from qualifying purchases in the future.

One blood pressure ring now has an FDA clearance: Happy Health's blood pressure software, which runs on the Happy Ring. On Sep 3, 2026, FDA cleared it (K254000) to give spot-check systolic and diastolic readings in adults 22 to 50, for measurement and display only, with no diagnosis. Hilo Core, a band and cuff system from Aktiia, is sold as a general wellness product that Hilo says is not FDA-cleared. Neither replaces a validated upper-arm cuff.

In 30 seconds

• Happy Ring: FDA-cleared BP software (K254000), ages 22 to 50, spot checks. Prescription through Happy Sleep; no retail price.
• Hilo Core: wrist band plus upper-arm cuff. Wellness product; we found no FDA clearance for the band. $89.99 plus a required $149.99 first-year subscription.
• Not for: diagnosing high blood pressure, adjusting medication, or people the labeling excludes (atrial fibrillation, pregnancy and others).
• Still the reference: a validated upper-arm cuff, used the right way.

No listing on this page is paid or sponsored.

Can a ring really measure blood pressure?

A ring can estimate blood pressure, and one ring system has shown FDA enough data to be cleared for spot checks in a narrow group of adults. That differs from measuring it the way a cuff does.

A cuff inflates and reads pressure changes as it deflates (oscillometry). A ring typically shines light into the finger (photoplethysmography, or PPG), reads how blood volume changes with each beat, and uses software to estimate systolic and diastolic numbers from it.

The European Society of Hypertension (ESH) has written about why this is hard. In its 2022 statement, the ESH working group said cuffless devices have specific accuracy issues that make the standard validation protocols for cuff devices inadequate on their own. It said validation needs to address cuff calibration, how stable readings stay after calibration, whether a device tracks real changes in pressure, and the use of machine learning. ESH guidelines do not recommend cuffless devices for diagnosing or managing hypertension. In 2023 the group proposed six validation tests, including position, sleep and exercise.

A ring can produce a reading that matches a reference in a study. Whether it holds up in daily life is a separate question.

Happy Ring: what the FDA clearance covers

What is cleared. FDA lists three Happy Health 510(k) clearances, so "FDA-cleared" is the right term, not "approved."

The indication, in FDA's words. The K254000 summary describes software as a medical device "intended to be used in patients who have a need for non-invasive blood pressure monitoring." It is for subjects aged 22 to 50 and derives "spot-check measurements of systolic and diastolic blood pressure in a home or clinical setting." It is "intended only for measurement and display; it makes no diagnosis."

Who it is not for. The labeling excludes people with arrhythmias such as atrial fibrillation, severe vascular disease or radial-artery abnormalities such as Raynaud's syndrome, people on vasoactive drugs, and people who are pregnant. It is not for use during motion or low perfusion.

How it works. The software uses PPG, electrodermal activity, accelerometer and skin temperature signals from the ring, worn on the index finger. It needs no cuff calibration or demographics, and the company states it "does not use machine learning."

How it was tested. In its own study, summarized in the 510(k), Happy Health reports 85 subjects and 850 paired readings compared with an arterial line, an invasive reference. That study reports a systolic mean error of 0.81 mmHg (SD 6.09) and a diastolic mean error of 0.12 mmHg (SD 3.16), and says the device met both criteria of the ISO 81060-2 standard. The predicate was the Aktiia G0 (K250415).

What is not cleared or not stated. The clearance is for spot checks. The FDA record does not describe continuous monitoring, alerts, or hypertension diagnosis. Happy Sleep's Sep 25, 2026 support post says members now see an "average overnight blood pressure" built from readings taken during sleep. That phrase is the company's; it does not appear in the FDA summary.

How you get one. Happy Sleep says the Happy Ring "is an FDA-cleared Class II medical device, available with a prescription from a Happy Sleep physician." It comes bundled with a home sleep test service that Happy Sleep says many insurers cover. We found no retail price.

Hilo (formerly Aktiia): band + cuff

Hilo, a brand of Swiss company Aktiia, sells Hilo Core in the US: a screenless wrist band, an upper-arm cuff and an app.

FDA status. Hilo's own FAQ says: "Hilo Core is a general wellness product in the United States. It is not FDA-cleared as a medical device." For the band, we found no FDA clearance; openFDA has no 510(k) records under the applicant Hilo.

The cuff. Hilo's product page and launch release call the included upper-arm cuff FDA-cleared. We could not match it to a 510(k) record, so we give no K-number. Hilo cites a peer-reviewed 2023 validation study of the cuff, run under its earlier Aktiia name in 85 adults using the ISO 81060-2:2013 protocol. In that study (Blood Pressure Monitoring, 2023), the cuff showed a mean difference of 1.3 mmHg systolic (SD 7.11) and minus 0.2 mmHg diastolic (SD 5.46), meeting both criteria. That is company-run data.

The related cleared device. FDA cleared the Aktiia G0 Blood Pressure Monitoring System (K250415, Jul 2, 2025, product code DXN). In the comparison table inside Happy Health's own K254000 510(k) summary (not an Aktiia document), G0 is described as a spot-check system for adults 22 to 59 with wrists from 14 to 21 cm, with cuff calibration every 24 hours. Hilo says that clearance "applies to the Aktiia G0 product, not to Hilo Core as sold in the U.S."

How it works day to day. Hilo's launch release says the band takes 30 to 35 readings a day. CNET's Jul 21, 2026 first look reported a 15-day battery, with cuff calibration in the first four days, then monthly.

Price. Hilo's product page lists $89.99 for the band with calibration cuff plus a $149.99 12-month subscription, $239.98 at checkout, then $149.00 per year. The launch release says it is HSA and FSA eligible.

What Hilo itself says not to do. Its FAQ says cuffless wellness information "should not be used to change medication or as a substitute for validated cuff-based measurements."

How accurate is cuffless BP?

The numbers look good inside each company's own study. We found no independent test of these products in everyday use.

• They are company data. Neither comes from an independent lab.
• They describe controlled settings. ESH flags motion, position and change over time; Happy's labeling excludes motion.
• Mean error is not the whole story. A near-zero mean can hide individual misses; in Happy Health's own study, the systolic SD was 6.09 mmHg.
• Validation applies to the tested group. Happy was cleared for ages 22 to 50 only.

The ESH 2022 statement concluded that cuffless devices have "considerable potential," but that "fundamental questions regarding their accuracy, performance, and implementation need to be carefully addressed before they can be recommended for clinical use."

Comparison table

Other options

Omron HeartGuide

HeartGuide is a watch with a small inflatable cuff, so it measures with oscillometry. FDA records list two Omron 510(k) clearances that match the HeartGuide sizes: K182481 (HEM-6410T-ZM, Nov 9, 2018) and K190693 (HEM-6410T-ZL, Apr 17, 2019), both under product code DXN. K182481 covers adults with 16 to 19 cm wrists. Its 2019 US launch price was $499 (Omron's Jan 8, 2019 release); we did not verify a current price.

Signal Ring

Vital Signals' Signal Ring opened for $399 preorders on Jul 16, 2026 with no subscription, according to CNET and the company's launch release. CNET reported that it has not been reviewed or cleared by FDA, and we found no FDA clearance either. The company cites an unpublished 451-person study of its own. On Oct 7, 2026 its product page still said it "begins shipping in October"; we found no report of rings shipping.

Samsung

We found no FDA clearance in openFDA for a Samsung blood pressure feature, so we do not cover it as a US option.

Oura and WHOOP

We found no FDA clearance for blood pressure on the Oura Ring 4. Oura does not claim to replace a cuff (CNET).

The WHOOP 5.0 offers Blood Pressure Insights. WHOOP's only openFDA 510(k) record is for its ECG feature (K243236). In a warning letter dated Jul 14, 2025, FDA told WHOOP that Blood Pressure Insights was being marketed without clearance or approval. In a Jun 17, 2026 closeout letter, FDA said it "does not intend to enforce" device requirements for the feature as modified. That is not a clearance. See our WHOOP vs Oura comparison.

Who should and shouldn't use one

A cuffless device may make sense if you:

• Are a healthy adult curious about patterns and already own a validated cuff.
• Fall inside the labeled group (for Happy, ages 22 to 50 without the listed exclusions) and are already using Happy Sleep.

Skip it, or talk to a clinician first, if you:

• Have atrial fibrillation or another arrhythmia, are pregnant, take medication that affects blood pressure, or have Raynaud's or severe vascular disease. Happy's labeling excludes these groups.
• Have been diagnosed with high blood pressure and want to manage it. ESH does not recommend cuffless devices for diagnosis or management.
• Want a reading to decide whether to change your treatment.

How to get a reliable home reading with a cuff

A cuffless device is a supplement at best. For a reliable cuff reading:

1. Pick a validated upper-arm cuff. Ask your pharmacist or clinician which models qualify.
2. Get the right cuff size. Measure around your upper arm and match the cuff range.
3. Prepare. Sit quietly and rest before measuring.
4. Sit correctly. Back supported, feet flat, legs uncrossed, arm supported at heart level, cuff on bare skin.
5. Repeat. Take two or more readings a minute apart, morning and evening, over several days, and keep a log.
6. Share the log with your clinician.

If a reading is very high and you have symptoms such as chest pain, shortness of breath, severe headache, or weakness or numbness, get urgent care.

FAQ

Is there an FDA-cleared blood pressure ring?

Yes, with limits. Happy Health's BP software for the Happy Ring (K254000) is cleared for spot checks in adults 22 to 50, for measurement and display only.

Is Hilo FDA-cleared?

The Hilo Core band is not; Hilo calls it a general wellness product. Hilo says its cuff is FDA-cleared, but we found no matching K-number. Aktiia G0 (K250415) is cleared, and Hilo says that clearance does not cover Hilo Core.

Can a blood pressure ring replace my cuff?

No. Hilo says its cuffless readings are not a substitute for cuff readings, Happy's labeling is measurement and display only with no diagnosis, and ESH does not recommend cuffless devices for diagnosing or managing hypertension.

How do I get a Happy Ring?

Through Happy Sleep, with a prescription from a Happy Sleep physician. We found no retail price.

Does Oura or WHOOP measure blood pressure?

We found no FDA clearance for blood pressure on either. WHOOP's Blood Pressure Insights is a wellness feature, not a cleared device.

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Disclaimer: This article is for information only and is not medical advice. Cuffless blood pressure devices aren't a substitute for a validated cuff or for care from a clinician. Don't start, stop or change blood-pressure medication based on a wearable reading. If you're pregnant, have an irregular heartbeat such as atrial fibrillation, or take blood-pressure-affecting medication, talk to your clinician before relying on any cuffless reading. A very high reading with symptoms such as chest pain, shortness of breath, severe headache, or weakness or numbness needs urgent medical care. BiohackList may earn commissions from qualifying purchases in the future.

Affiliate note: We earn no commissions on these products today. See our disclosure.

How we researched this: We checked every FDA claim against openFDA and read the K254000 summary. Accuracy figures are attributed to the company that ran each study.

Last checked: Oct 7, 2026.

Sources

• openFDA 510(k) K254000, Happy Health Blood Pressure Monitor
• FDA 510(k) summary K254000
• openFDA 510(k) K240236, Happy Ring Health Monitoring System
• openFDA 510(k) K242224, Happy Health Home Sleep Test
• openFDA 510(k) K250415, Aktiia G0 Blood Pressure Monitoring System
• openFDA 510(k) K182481, Omron HEM-6410T-ZM
• openFDA 510(k) K190693, Omron HEM-6410T-ZL
• Happy Sleep
• Happy Sleep support, Happy Sleep now includes Blood Pressure Monitoring (Sep 25, 2026)
• Hilo, Is Hilo Core FDA-Cleared? (Jul 20, 2026)
• Hilo Core product page
• PR Newswire, Hilo launch release (Jul 21, 2026)
• CNET, Hilo Core first look (Jul 21, 2026)
• CNET, Signal Ring (Jul 16, 2026)
• Stergiou GS et al., Cuffless blood pressure measuring devices: review and statement by the ESH Working Group, J Hypertens 2022
• Stergiou GS et al., ESH recommendations for the validation of cuffless BP devices, J Hypertens 2023
• Omron HeartGuide US launch release (Jan 8, 2019)
• MD+DI, FDA closes WHOOP warning letter on Blood Pressure Insights (Jun 2026)
• FDA warning letter to WHOOP (Jul 14, 2025)
• Alexandre J et al., Aktiia cuff validation, Blood Press Monit 2023 (PMID 36795403)
• Signal Ring product page (checked Oct 7, 2026)