Wearables Have Measured Steps, Sleep, and Glucose. Is Cortisol (and Other Hormones) Next? – The Spoon

Over the past decade, millions of Americans, myself included, have started quantifying our daily activity and biomarkers using wearables such as smartwatches and rings.

First, it was activity tracking, then heart rate, and then sleep. More recently, over-the-counter continuous glucose monitors became widely available, giving broad access to real-time insights into the state of our metabolism.

What’s the next stop? If a Stanford spinout named Adaptyx has its way, consumers will soon have real-time insight into their hormones and other molecular signals in their bodies, starting with cortisol.

This week at the American Diabetes Association’s 86th Scientific Sessions, the startup is presenting findings from what it claims is the first continuous, multi-day measurement of free cortisol in humans using a wearable sensor.

The company’s technology uses a wearable patch with programmable DNA-based molecular switches that change shape when they bind to a target molecule, generating an electrical signal that can be measured continuously. Cortisol is the first target, but Adaptyx says the same technology could eventually be used to monitor hormones, electrolytes, proteins, pharmaceutical compounds, and other biomarkers in real time.

If Adaptyx can take what it has demonstrated in early studies and build a consumer-ready wearable around the technology, it would be a significant breakthrough. Continuous biochemical monitoring has, for the most part, meant glucose. Everything else—from hormones and proteins to drug levels and inflammatory markers—typically requires periodic blood draws and laboratory testing.

Broad hormone monitoring is a big idea, but even if the company never moves beyond cortisol, giving people a real-time view of the body’s primary stress hormone could have a significant impact on millions of lives.

Cortisol has a big impact on what goes in our bodies, influencing everything from glucose regulation, blood pressure, inflammation, immune function, sleep, recovery, mood, and stress response. Despite its impact, to get a picture of our cortisol levels today requires blood, saliva, or urine tests, and these provide only isolated snapshots of a hormone that fluctuates dramatically throughout the day.

In Adaptyx’s first human studies, the company’s wearable tracked cortisol changes following an oral hydrocortisone challenge and captured the body’s natural overnight cortisol rhythm, including the cortisol awakening response that occurs shortly before waking. The company says it has now accumulated more than 400 hours of human monitoring data and is pursuing an FDA pathway for the device.

Adaptyx isn’t the first startup to try to measure cortisol. In 2022, biometrics startup Nowatch partnered with Philips and claimed to have developed a wearable device that could infer cortisol levels by monitoring electrodermal activity (EDA), measuring changes in skin conductance caused by sweat gland activity. According to the announcement at the time, Philips developed algorithms that used those skin-conductance changes to estimate stress levels and infer cortisol-related responses.

Since the announcement in 2022, Philips and Nowatch have dialed back talk of cortisol measurement and largely focus on stress response as determined through measurement of general skin conductance (EDA) and Heart Rate Variability (HRV). This isn’t that far removed from how Garmin tracks stress, using HRV and heart rate to calculate it stress score.

However, neither approach is a direct measurement of cortisol, which is what Adaptyx says its technology can provide. A continuous view of cortisol could help doctors better manage conditions such as diabetes, hypertension, and adrenal disorders, and could eventually provide consumers with a new lens on how stress, sleep, exercise, and nutrition shape their health.

Glucose has become one of the defining biomarkers of the metabolic health movement over the past few years. With this technology, Adaptyx hopes to unlock a new wave of cortisol-monitoring applications and services that help consumers better understand and manage the effects of stress on their bodies.

Whether the company can achieve those lofty goals is far from guaranteed. As demonstrated by the Nowatch and Philips effort, the wearables industry is filled with examples of physiological signals that were technically measurable but never became truly actionable.

It’s also somewhat unclear how intrusive the Adaptyx technology will be. Continuous glucose monitors require a sensor to be inserted beneath the skin, a meaningful step beyond simply wearing a watch or ring. While tens or perhaps hundreds of thousands of consumers have experimented with over-the-counter CGMs, adoption remains a tiny fraction of what companies such as Apple, Fitbit, and Oura have achieved with their wearables.

That said, if Adaptyx ultimately achieves its broader vision of continuous molecular monitoring, my guess is that many consumers interested in longevity, performance, and wellness will be willing to wear a sensor on their skin to gain a clearer picture of what’s happening inside their bodies.