The Bleeding Edge of Femtech

Menstrual trackers aim to reconceptualize women’s health

As a woman in the consumer tech space, I’ve become more and more aware of gender-biased product development, and for me, there’s no better example than the lack of progress by wearables in the women’s health space. A trend I’ve been following with great interest over the past year is the emergence of wearable tech solutions targeted at the menstrual cycle, or alternatively, if that term makes you uncomfortable — as anecdotal evidence informs us that it does for many people in professional spaces — “femtech”.

Until recently women’s health features on wearables have been limited to a fertility application, even though the hormone cycle affects many other areas of a woman’s health including energy levels, training performance and emotions. But this might be about to change. At the end of 2021, Whoop launched a menstrual cycle coaching feature that I believe goes some way to present a more holistic view of women’s health by helping “people who menstruate understand how to train using their Whoop data”.

If you’re not familiar with the concept of gendered product design, I’ll take this opportunity to encourage you to read a book by British journalist Caroline Criado Perez. Invisible Women: Exposing Data Bias in a World Designed for Men in 2019 explores the “gender data gap”, arguing that a variety of factors — including lack of gender diversity in technology workplaces and research biases — have led to products that are developed and marketed under the assumption of being gender-neutral, but in reality are optimized for the male experience.

We can see this throughout the tech industry from physical design choices to features and application development. As a reminder of a few examples that persist today: smartphones are often too big for female hands or pockets; smartwatches can be too large for female wrists (I say this from experience); and calculations for calories burned have reportedly always used the average male metabolic rate as the benchmark.

One of the starkest examples in the wearables space is the lack of features that support women’s health in a meaningful way. For clarity, I’m talking about features to help deal with symptoms of the female hormone cycle, for example, periods and associated fatigue, pain, hot flushes and difficult emotions.

Pretty much every wearables provider claims to offer “women’s health” functionality in their existing capabilities, but more often than not, this just means a period-tracking feature. This lets users log periods in a calendar to help plan or avoid pregnancy, although crucially, no company markets this feature as a fertility solution to avoid potential backlash over unintended pregnancies. Herein lies the problem; the female hormone cycle affects women in many ways beyond period planning and fertility. It can affect their feelings, general well-being, training performance and more — these are all customer problems that are yet to be addressed by the industry.

While other health insights offered on wearables have been refined over and over again between product launches, the period-tracking functionality hasn’t enjoyed any wholesale changes. Until very recently, all menstrual cycle-tracking applications were based on period prediction algorithms that use self-reported period data alone.

Fitbit and Oura are two companies that have advanced this feature with their respective Fitbit Sense and Oura Ring Gen 3 devices, using biometric data to improve the algorithm that predicts when a woman might expect her next period. This was achieved by aggregating self-reported period data with temperature readings — a woman’s temperature is cooler in the first half of her cycle when oestrogen is high and increases during the second half when progesterone is high, as shown in the graph below.

This improved accuracy offered by Oura and Fitbit will give users more insight into where they are in their cycle and allow them to identify their personal trends (you can read case studies about how Oura customers, for example, have become more aware of their personal cycles here). But without timely recommendations of how this might be affecting users, or how to respond to these changes, it’s difficult to see what value this feature really offers beyond fertility tracking. Even for this use, both companies acknowledge that if the person is using a hormonal contraceptive — as many do — the period prediction feature won’t work.

In my opinion, Whoop’s solution appears much more distinct and value-adding. Rather than focussing on fertility tracking, the value of the feature centres on its ability to accurately predict a user’s current stage in the female hormone cycle and inform coaching recommendations for training and recovery. In doing so, the company effectively joins the dots between different health measures and offers feedback to improve them.

But how does it differ from other features on the market? Much like Oura, Whoop uses self-reported period data and temperature readings, but uses contraception information in the predictive algorithm that guesses what stage in the hormone cycle a woman is in. This feature responds to research published in the British Medical Journal, which suggests that the ability to recover throughout the natural menstrual cycle is different when hormonal birth control is used, and that this also varies depending on the type of hormonal birth control.

This is undoubtedly an effective product differentiator for Whoop, but for me, what’s more significant about this new feature is how it reconceptualizes women’s health in the wearables space. It acknowledges that the female hormone cycle affects women in different ways and offers personalized feedback to help them manage their symptoms. By giving users a wider view of the impact of their monthly cycle beyond fertility, Whoop shows it’s making a conscious effort to really understand the problems women face, and this is enabling the company to design solutions that better cater to their needs.