Medical devices & diagnostics · Metabolic testing
PNOE
A portable breath analyzer built in Athens and sold to gyms, longevity clinics and health professionals. Three peer reviewed papers have now measured it against laboratory reference systems, and they do not agree with each other.
A mask, ten minutes, twenty three numbers
A client sits down in a clinic or a gym, puts on a face mask, and breathes normally. A small analyzer reads the oxygen going in and the carbon dioxide coming out. Software turns that exchange into a report: how much oxygen the body can use at peak effort, how many calories it burns at rest, how much of that fuel is fat and how much is carbohydrate.
The method is indirect calorimetry and it is more than a century old. What is new is where it happens. For most of that century it happened in hospital laboratories and university exercise physiology suites, on carts that cost tens of thousands of dollars and needed a trained technician.
PNOE sells the argument that the same measurement can happen behind the front desk of a gym. Its website promises 23 biomarkers from a test taking under ten minutes with no blood draw. Trade press in August 2025 put it at eight minutes. Endeavor Greece calls it a twelve minute test.
Why this category is hard to referee
Every portable analyzer faces one question: how close is it to the cart it replaces? In 2024 a team at Maastricht answered it for fifteen systems at once.
Bas Van Hooren, Tim Souren and Bart Bongers fed a certified metabolic simulator through each machine, so the true value was known in advance rather than inferred from a second device. They invited every manufacturer to calibrate and handle its own system. Three declined. PNOE, the paper records, did not answer the invitations, so the researchers bought a unit from a local athletics coach and tested it anyway.
Two engineers and a stopped PhD
Apostolos Atsalakis grew up in Athens, took a degree in applied physics at the National Technical University there, then a graduate degree in nanotechnology at Cambridge. In 2016, starting a PhD, he began looking closely at breath analysis. He stopped the PhD to build the company instead.
He called a long time friend. Panos Papadiamantis had studied mechanical engineering at the same Athens university, taken a masters at Stanford, and worked in Silicon Valley before moving into research and risk analysis on nuclear technology. He joined as co-founder, having been named to Forbes 30 under 30 in 2015, before the company existed.
They incorporated in Delaware as ENDO Medical, Inc., with a San Francisco address. A USPTO assignment record shows that entity changed its name to PNOE, INC. effective July 18, 2022.
From a Cambridge lab to the gym floor
The company went through Y Combinator in the Winter 2019 batch. Endeavor Greece selected both founders the same year, names Social Starts and Y Combinator as investors, and shows roughly $10.7 million raised.
The customer list is the clearest signal of where the product sits. Trade press in August 2025 named Equinox, Liquivida, Four Seasons and NuBioAge as users. The company adds Cenegenics, MIT, UCLA, OURA, TONAL, Spartan Racing and Paris Saint Germain itself. A US reseller describes the output carefully: breath data related to wellness indicators, insights that may support individualized lifestyle plans.
That careful language is what a general wellness product sounds like.
What is proven, and what is still claimed
| Evidence | What the record shows | Source type |
|---|---|---|
| FDA record | No 510(k), PMA, registration and listing, or UDI entry found for PNOE, PNOE, Inc. or ENDO Medical, Inc., searched September 24, 2026. | Not found |
| Cleared comparators | COSMED K5 cleared as K162515 on June 20, 2017. COSMED Quark series K120146, December 11, 2012. KORR ReeVue indirect calorimeter K021490, January 2, 2003. The reference devices in this category carry clearances. | Public record |
| Validation against COSMED Quark CPET, 2019 | Frontiers in Sports and Active Living. 22 subjects on a cycle ergometer. Correlations of 0.98 for oxygen uptake, carbon dioxide output and ventilation. Mean percentage differences of 2.2, 2.3, 1.4 and 0.6 percent. Retest reliability above 0.90. | Peer reviewed |
| Disclosure on that 2019 paper | Its conflict statement says the senior author advised the manufacturer from November 2016 to March 2018. Funding came from Rutgers start-up funds and a Harokopio University programme. The company calls the device independently validated by Georgetown University, VA in Maryland and Rutgers University, without that disclosure. | Claim omits the disclosure |
| Metabolic simulator comparison, 2024 | Scandinavian Journal of Medicine and Science in Sports, 15 systems. PNOE mean relative errors: 44.3 percent for ventilation, plus 8.25 percent oxygen uptake, plus 3.39 percent carbon dioxide output, minus 4.36 percent respiratory exchange ratio, minus 39.5 percent energy from carbohydrate, plus 76.1 percent energy from fat, plus 8.16 percent total energy expenditure. Day to day variation above 12 percent, and up to 37 percent in carbon dioxide fractions. No data recorded above 60 breaths per minute. | Peer reviewed |
| Calibration finding, 2024 | Same paper: manufacturer guidance requires only ambient air calibration, and under that alone errors were larger still, at 4.9 percent over for oxygen uptake, 16.3 percent under for carbon dioxide output, 17 percent under for respiratory exchange ratio. | Peer reviewed |
| Validation against COSMED K5, 2025 | Journal of Functional Morphology and Kinesiology. 21 healthy adults walking. Correlations of 0.60 to 0.79. The authors concluded the system is comparable to the K5. | Peer reviewed |
| Use as a research instrument | Two exercise studies in postmenopausal women, 2025 and 2026, used the analyzer to measure oxygen uptake, one under registration NCT05690295. No company sponsored trial found. | Public record |
| Patent position | US application 20190120821, Breath analysis device, priority April 12, 2016. Assigned by Atsalakis to ENDO Medical in 2016 and carried over by the 2022 name change. Repeated final rejections and three notices of appeal; the latest listed event is allowance, notice not yet mailed. Family filings in Europe, Japan and Brazil. | Public record |
Read plainly: the answer depends on how the comparison was run. The two studies that measured the device against another cart during human exercise found agreement good enough to publish. The one that measured it against a certified simulator, where the true value was known, found large errors in ventilation and in the fat and carbohydrate split, plus poor repeatability between days. Those substrate numbers are the ones a nutrition report leans on. Nothing in the FDA record settles it, because there is nothing in the FDA record.
What to watch
- Any FDA submission, device listing or CE certificate. A move toward clinical interpretation would require one.
- A fourth validation study, simulator based and with the manufacturer taking part, which would settle the 2019 versus 2024 disagreement.
- A new Form D. The last was filed in June 2016, and roughly $10.3 million of the reported total has no SEC filing behind it.
In their words
“You can understand a lot of things about the human health through breath that you can’t really get from any other specimen of the human body you can analyze.”
Panos Papadiamantis, co-founder, TopDoctor Magazine, 2023 · Interview
“It is the only assessment known to mankind that can non-invasively, in just 10 minutes, analyze the combined operation of your heart, your lungs, your circulations and your cellular health.”
Panos Papadiamantis, TopDoctor Magazine, 2023 · Interview
“We really don’t frame ourselves as a longevity company, a weight loss company, a performance company, or a mental health company, but it is something that we can very effectively support for the businesses that we serve”
Panos Papadiamantis, TopDoctor Magazine, 2023 · Interview
“Pnoe is reshaping how we measure longevity and optimise life.”
Panos Papadiamantis, quoted in Health Club Management, August 2025 · Trade press
“Our data indicate that the portable metabolic cart PNOE can accurately determine respiratory gases over a wide range of exercise intensities, in healthy individuals, in a controlled laboratory setting.”
Tsekouras and colleagues, Frontiers in Sports and Active Living, 2019 · Peer reviewed
“LS served as scientific advisor to ENDO Medical, Palo Alto, CA, the manufacturer of the PNOE system, from November 2016 to March 2018.”
Conflict of interest statement, same paper · Peer reviewed
“The error of respiratory gas variables, substrate, and energy use differed substantially between systems, with only a few systems demonstrating a consistent acceptable error.”
Van Hooren, Souren and Bongers, Scandinavian Journal of Medicine and Science in Sports, 2024 · Peer reviewed
Related companies
Sources
- Public recordForm D, ENDO Medical, Inc., CIK 0001676914
- Public recordUS patent application 20190120821, with assignment and legal events
- Public recordopenFDA searches for PNOE and ENDO Medical
- Public record510(k) K162515, K120146 and K021490
- Peer reviewedValidity and Reliability of the New Portable Metabolic Analyzer PNOE
- Peer reviewedAccuracy of respiratory gas variables, substrate, and energy use from 15 CPET systems during simulated and human exercise
- Peer reviewedAssessing the Validity and Reliability of the PNOE During Walking Exercise
- Peer reviewedTwo resistance training studies using the analyzer in postmenopausal women
- IndependentBreath Analysis: How the Invention of PNOE Could Change Healthcare Forever
- IndependentBreath analysis tech for fitness market
- IndependentPnoe’s breath analysis tech for fitness market
- IndependentCompany and entrepreneur profiles
- IndependentWhy Metabolic Testing Is Becoming a Business Strategy
- CompanyPNOE profile, batch and team size
- CompanyHome page, About Us and Metabolic Testing Validation pages
- PartnerPNOE Biomarker Analyzer product page
Profile researched and written by Healthcare Discovery. Last updated September 29, 2026.
