For the longest time, if you actually wanted real answers about what was happening with your hormones, you had no choice but to drag yourself to a lab for a blood test. And if you wanted any kind of convenience? You were stuck with guesswork. Marking days on a calendar app, peeing on ovulation strips or hoping your smart ring’s temperature data was accurate.
It always felt so limiting, especially when we can track our steps, heart rate and sleep so effortlessly. Enter: Clair, a continuous hormone tracker for women.
A Stanford-born startup, Clair is trying to completely change the game. They’re building what they claim is the world’s first continuous, noninvasive hormone tracking wearable. Instead of getting occasional snapshots of your hormones, Clair wants to track your hormonal patterns 24/7, right from your wrist.
Yes, you read that right- actual hormone tracking, all day and all night, without needles or guesswork. The idea sounds almost futuristic: What if your hormones became as easy to track as your heart rate or sleep score? So let’s break it all down: what Clair is, how it works, what it promises to track and whether it’s actually as revolutionary as it sounds.
What Is the Clair Continuous Hormone Tracker?
And now, the million-dollar question: what is Clair?
It’s a minimalistic yet futuristic bracelet that has been specifically engineered to monitor the health of female hormones. It may look just like any other wrist accessory that you might like to wear daily, but its purpose goes much further. The fact is, Claire isn’t another fitness watch or smart ring. On the contrary, it offers a unique experience and a completely different approach to continuous health monitoring.
As opposed to ordinary devices that treat menstrual health tracking as a minor addition to the list of features, Clair makes it their priority number one.
Basically, the philosophy of this device is that your hormones deserve the same treatment as other biological parameters, such as heart rate, sleep or stress. Instead of directly sampling blood, saliva or urine, Clair uses a multi-sensor system + AI models to infer hormonal changes in real time. It focuses on key reproductive hormones like:
- Estrogen
- Progesterone
- Luteinizing Hormone (LH)
- Follicle-stimulating Hormone (FSH)
This makes it fundamentally different from existing wearables. Most devices treat cycle tracking as an add-on. Clair treats it as the primary signal.
Why Hormone Tracking Matters
It gives me the ick when people tie hormones to just fertility or menstrual cycles. Hormones are the main driver behind most processes within our bodies. They affect our levels of energy, sleep, mood and metabolic rates, our recovery post-exercises and even the way we respond to stressors. They are in charge.
Until now, hormone monitoring technology has offered you two different options– either clinical-level precision provided by blood tests or convenience offered by applications and ovulation strips. The issue? Blood work can’t be continuous and apps and strips can be wrong. That creates a major problem.
For example, you may feel very tired and worn out despite having high scores both in your sleep patterns and in your exercise recovery process. You may be doing all sorts of exercises, but still have trouble with gaining strength or motivation. All because you don’t realize what stage of your cycle you are currently in.
Without the help of a consistent, objective data flow, you can barely get any insights into your hormonal situation. It is here that Clair comes to your rescue.
How Does Continuous Hormonal Tracking Work?
This is where I am truly excited! Clair does not perform hormone measurements in your bloodstream as any standard test would do. Rather, it relies on what is called a physiological inference. That is, when your hormones spike or drop, there will be very small but noticeable changes taking place simultaneously in other systems. The device detects all these small fluctuations and interprets them into your hormone status.
Clair continuously monitors such signals as skin temperature, heart rate, heart rate variability (HRV), breathing rate, sleep stages, electrodermal activity and movement patterns using a powerful 10-sensor stack.
Here is what happens behind the scenes:
Step 1: Multi-Signal Data Collection
Data are being collected continuously by the wearable device from your cardiovascular, thermoregulatory and nervous systems around the clock.
Step 2: Machine Learning Based Pattern Detection
Advanced machine learning models examine all these patterns and the way they evolve over days and weeks.
Step 3: Hormonal Inference
Based on detected patterns, Clair infers your current hormone state in real-time.
For instance, if progesterone level increases, it will be reflected by increased skin temperature and altered HRV readings. Changes in estrogen levels will affect your sleep quality and recovery signals.
Continuous vs Periodic Tracking
| Approach | Method | Limitation |
|---|---|---|
| Blood test | Direct measurement | Infrequent |
| Ovulation strips | LH detection | Miss timing |
| Smart rings | Temperature trends | Limited scope |
| Clair | Multi-signal AI inference | Model-dependent |
The main benefit is that it is done continuously. That means no guessing on average values, but adapting to your unique physiological characteristics, including PCOS.
What Hormones Could Be Tracked?
While Clair currently only works on reproductive hormones, there are many potential applications for the technology in the future as a result of its ability to measure different patterns of hormones in women’s bodies. Currently, the company concentrates on the following hormones:
- Estrogen (estradiol) – it is responsible for everything ranging from regulating women’s energy level to defining how mentally alert they feel.
- Progesterone – the hormone helps to confirm whether one has ovulated and affects the quality of sleep and women’s fatigue levels.
- Luteinizing hormone (LH) – it is the hormone that triggers ovulation and thus its measurement can be quite useful for anyone who is looking for their fertile window.
- Follicle-stimulating hormone (FSH) – this particular hormone is important to consider due to its role in the development of eggs.
It becomes extremely important to detect this hormone in reproductive health monitoring as well as perimenopause or menopausal symptoms tracking.
The more advanced the technology becomes, the more other significant hormone levels will be included by Clair, such as:
- Cortisol levels for identifying stress and recovery patterns
- Melatonin signals for getting deeper insights into sleep quality
- Metabolic hormones impacting insulin sensitivity
In the meantime and at least for the early stages of development, Clair is not going to provide you with accurate hormone values like in blood tests. The system is designed to track visible patterns in your hormone fluctuations and their impact on your well-being.
How Clair Compares with Existing Wearables
Despite entering a pretty crowded wearable industry, Clair doesn’t compete with traditional fitness trackers. Rather, it addresses an entirely new pain point that makes its solution unique and innovative.
Continuous Glucose Monitors (CGMs)
The popularity of CGMs, especially non invasive CGMs like Biolinq Shine and PreEvnt’s Isaac blood glucose monitor, is rising thanks to their ability to provide continuous monitoring of blood glucose via an implanted sensor. These devices offer a wealth of personalized insights, helping to make informed choices based on immediate and continuous data collection.
Clair is making a very clear parallel here. You’ll see this statement used in every single one of their pitches: “Hormones are the new glucose.” While CGMs monitor glucose levels directly from the user’s interstitial fluid, Clair doesn’t monitor anything directly.
Instead, it calculates your hormones using multiple signals with the help of advanced AI. Nevertheless, both technologies create a similar feedback loop where seeing the results changes your behavior.
Smart Rings
I have worn the Oura ring for quite some time now and I really love it. It’s amazing at sleep tracking, temperature trends and recovery tracking. I especially love it for cycle predictions, but these mostly depend on temperature trends.
Now we can argue that Evie Ring is made especially for women’s cycle tracking, however, it too depends on temperature trends and the same couple of sensors. Clair’s approach is more holistic.
Instead of focusing on a couple of proxies for the cycle, it analyzes several biosignals in an attempt to map actual hormones using 10 different sensors. Cycle tracking is not just an add-on here, but the whole purpose of the device.
Smartwatches & Fitness Trackers
Apple Watches and Fitbits are pretty good for analyzing heart rate, sleep trends and allowing users to enter their menstrual cycle. However, they do not predict hormones themselves. The algorithms used are generic enough and there is still too much manual entry involved.
What makes Clair different is its focus from the beginning– it was made specifically for tracking cycles.
Real-World Use Cases
And that is where things get really interesting with Clair when considering all the ways it might change how you live your life!
Fertility Tracking
If you are looking to conceive or learn more about your menstrual cycle in general, then Clair could revolutionize everything you thought you knew. Standard fertility tests can detect an increase in your luteinizing hormone only, indicating ovulation is about to happen. With Clair, you not only get an indication of your LH surge, but your progesterone increase too, confirming actual ovulation.
This would result in more accurate identification of your fertile window and far fewer ovulation strips. And that would come very useful for women with irregular menstrual cycles! Imagine what this could mean in terms of convenience and reduced stress when tracking fertility!
Stress Monitoring
The role hormones play in regulating your mood, your level of energy, anxiety and even your sleep can hardly be overestimated. Although Clair currently does not measure your cortisol levels, a multi-signal approach and analysis could help recognize stress through different changes in heart rate and variability, sleep quality and other parameters.
Instead of simply stating “You did not sleep well” through the app, there’s the possibility that it can tell you the reasons behind it by linking your hormones to those bad days. It definitely sounds promising.
Metabolic Health & Performance
Hormones play an essential role in determining how our bodies will function in regards to metabolism, fat storage, muscle recovery and workout performance. Through the link between hormones and the data on recovery and performance, Clair can enable you to optimize your workouts based on what stage of your menstrual cycle you’re at.
It is especially important to know this because our physiology changes monthly, while all of the fitness advice is still geared toward men with stable hormones.
Limitations and Challenges
While the prospects of Clair sound groundbreaking, just like any other wearable I’ve tried, it’s not perfect. It’s important to be realistic about where it stands right now.
- Accuracy and Validation
Currently, the average level of cycle phase classification accuracy is 94.1% and the average sensitivity when detecting LH surges stands at about 87%. While impressive, these numbers come from a rather limited research. The company will need larger-scale, independent confirmation of its accuracy among a broad population of women of all ages, cycle type and lifestyle.
- Inference-Based Algorithm
Any inference-based algorithm relies heavily on the training database it was created from. Clair doesn’t measure hormones directly. It estimates them through patterns and signals. That means the readings are predictions rather than exact values.
While it should work well in normal cycles, in edge cases like very irregular cycles, certain medical conditions, extreme stress or perimenopause, the accuracy could drop.
- Regulatory Status
Clair is likely to be initially launched as a consumer health and wellness product rather than as a medical device. They plan to obtain an FDA approval down the line.
- Cost and Availability
While no official information regarding the pricing has been released yet, Clair seems to fit into the category of premium wearables. Given that, there might be some valid concerns about whether many people will be able to afford it and whether it will be available globally.
- Data Security
Your hormonal data is among the most private information one could disclose. I mean, just look at the recent Flo lawsuit. Clair says they use on-device data processing and limited cloud storage. This sounds promising, however, the transparency of their practices and policies will determine how much we can trust this new wearable on the market.
Is Clair Available Yet?
No, the Clair hormone tracker is not available yet. It is still in development. At this point, the company is concentrating on its clinical validation and preparing to launch by the end of 2026. Thus, if you want to purchase one, it would be best to give it more time.
Early access waitlists are available, allowing those who would like to stay in the loop to do so. However, no commercial versions of the product have been shipped out yet.
All of this makes Clair fit squarely into the category of an emerging product, something with immense potential but not yet proven in practice. I will definitely be watching it closely until the launch date arrives.
The Future of Hormone Tracking Wearables
But Clair isn’t just any random device. It’s a product of a much larger phenomenon that’s currently unfolding within the femtech sector. For instance, hormone tracking is shifting from its traditional framework, which is based on:
- Episodic data collection (a few days a month) → continuous monitoring 24/7
- Invasive approaches (blood draws and test strips) → non-invasive solutions
- Clinical applications → consumer-first products
However, this trend is applicable not only to Clair. The whole ecosystem of devices, software, services and infrastructure supporting these technologies is rapidly changing. Currently, we observe the emergence of saliva-based hormone testing, wearable biosensors, sweat analyzers and AI-driven platforms that can integrate information from various sources.
All of these trends and developments can be explained by the impressive projections. According to experts, the global market for hormonal tracking will rise from $325 million in 2025 to over $716 million by 2035. And that’s despite the current limitations and obstacles to adoption. Furthermore, femtech, in general, is forecast to achieve a valuation of $140 billion+.
Thus, if continuous glucose monitoring has redefined the notion of metabolic health during the previous decade, continuous hormone tracking may set the tone for the coming decade.
Breakthroughs in bio-sensing and nanotechnological devices have already moved hormone analysis out of the laboratory to make way for real-time monitoring even within the comfort of one’s own home, driven by continuous hormone monitoring technologies.
Wrap Up
Clair does not seem like just another fitness tracker or smartwatch on the market. It seems to represent a genuine paradigm shift, where health monitoring evolves from an emphasis on sporadic measurements to more complex processes that involve continuous recording of multiple metrics.
What Clair is trying to achieve in terms of technology is genuinely exciting. Their vision includes passive 24/7 monitoring, personalized feedback and real-time information on hormone levels. On the other hand, I have to admit that Clair has a long road ahead of itself to become a routine device in your life.
While there is some publicly available scientific evidence supporting Clair’s technology, real feedback is more crucial than any research. Moreover, the project relies solely on machine learning algorithms that infer results based on indirect data. In other words, there is still a lot of work to do.
But this project is promising and it’s ambitious. And if Clair really manages to achieve its goals, it will revolutionize the way women perceive their bodies and interact with them. Monitoring your hormones will soon become an experience that you can wear. This is one project I’m looking out for.
