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About Clue

Clue is a period tracking app, a trusted menstrual health resource, and a thought leader in femtech.

  • Download the Clue app on the App Store
  • Download the Clue app on the Play Store

By combining science and technology, we are actively changing the way people learn, access, and talk about menstrual and reproductive health around the world.

  • Download the Clue app on the App Store
  • Download the Clue app on the Play Store
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10 million people in over 190 countries rely on our app.

Our content is science-based and written by reproductive healthcare clinicians and science writers to provide people with essential, evidence-based education about health, periods, and sex via


monthly active users


monthly reach on web and social





We strive to create an app that’s accessible to our diverse community of users, taking into account gender, age, race, ethnicity, accessibility, education, country of origin, socioeconomic status, and all the other aspects of an individual's background. Clue is currently available in 20 languages and growing.

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What is “femtech”?

One of Clue’s co-founders, Ida Tin, coined the term femtech in 2016 to define the group of technologies that are designed to support and advance women’s healthcare.

The technologies within this category include fertility solutions, period and fertility tracking apps, reproductive system health care, women’s sexual wellness products, pregnancy and nursing care, period care goods, at-home fertility monitoring devices and general healthcare.

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An image of Ida Tin; Co-founder and Chairwoman at Clue

Ida Tin, 

Co-founder & Chairwoman

Ida knew immediately that in order for these products to be taken seriously, the market needed to be defined, so she suggested that Clue should begin to call itself a femtech company.

By defining the group of products that are associated with female health, we are creating an entirely new category of technology. Grouping these technologies paves the way for femtech conferences and VC’s to invest in femtech and create even more products within this segment that are important and needed in the world.

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We provide trustworthy information, data-driven tools, and emotional support for everyone with a menstrual cycle — as an empathetic, scientific companion from first period to last period.

the Clue logo
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Everyone with a cycle is empowered to make informed choices for themselves around menstrual, sexual, and reproductive health and well-being.



We earn people’s trust by honoring their privacy, being transparent about how we use their data, and providing them with honest and accurate health information.

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Care is at the core of everything we do, both in how we support and communicate with people, and in the products and technology we create for them. We genuinely wish to help them improve their lives and live more fully.

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Rooted in science, Clue’s brand and products were born out of research and data. We continually strive to find the most accurate, forward-thinking information on menstrual and reproductive health, only sharing what we confidently believe in and can provide evidence for.

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Clue founded in Berlin by Ida Tin, Hans Raffauf, Moritz von Buttlar and Mike LaVigne


The Clue app is launched on iOS


The Clue app is launched on Android

Clue raises a seed round of €500k


3 million monthly active users

Clue announces Series A funding


American College of Obstetrics and Gynecology (ACOG) rated Clue the number one period tracking app

Clue announces Series B funding


Clue Plus, the paid version of the Clue app, is launched

Launched the #justsayperiod campaign

2018 Encyclopedia for menstrual and reproductive health goes live

Clue collaborates with researchers at Oxford University on study on the impact of STIs on premenstrual symptoms


Irregular Cycles feature launched to help users identify symptoms of PCOS

First season of the Hormonal podcast goes live

Work begins with the Bill and Melinda Gates Foundation to explore how Clue can support global reproductive health research

Clue collaborates with researchers at the Kinsey Institute to publish study on global condom use during menses


Clue Pregnancy mode launched

Content Tab added to the app


Audrey Tsang and Carrie Walter become Clue’s co-CEOs

Clue Birth Control gets FDA approval

Clue announces funding for development and rollout of medical-grade features


Clue Birth Control piloted in the US

Clue Conceive is launched on iOS

Clue data is paired with survey data for study on COVID-19 and the menstrual cycle

Clue app redesign is released


The Clue app becomes CE marked as Class 1 medical device

Clue Conceive is launched on Android

Clue together with the Bill and Melinda Gates Foundation, releases study on heavy menstrual bleeding (HMB)

Record-breaking equity crowdfund with over 5000 individual investors (85% female)

Clue Perimenopause is launched

Audrey Tsang becomes CEO

Health Conditions feature is added in-app to help
close the diagnosis gap


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2M+ ratings

Why people love Clue

Accurate, informative, easy to use! The clean and fun design makes tracking your cycle, dare I say, fun?

Nicole Layton

Clue is such an invaluable app! As someone with PCOS and other health conditions that contribute to painful and irregular cycles, Clue has helped me to see patterns in my cycle.

Sophie Purdie

This app is almost scary with how accurate it is in prediction of ovulation and menstruation times. I'd give 10 stars if I could.

Esther Mungai

Proudly female founded and led

Audrey Tsang (Clue’s former Chief Product Officer) became Clue’s Co-CEO in March 2021, and sole CEO in October 2023. She champions a user-first, insight-led approach to product innovation. Audrey firmly believes in the potential of tech and data-driven self-tracking to help close the empathy gap in female healthcare.

a photo of Audrey Tsang
a photo of Audrey Tsang
a photo of Audrey Tsang

Audrey Tsang, CEO

Rhiannon White CPO

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Greg Ryzhov CTO

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Sarah Ottawa Head of People

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Amanda Shea PhD Head of Science

We’re always working on something exciting

Check out the links below to see what we've been up to.

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Clue Period Tracking App

Available on iOS and Android in 20 languages, the Clue app features cycle predictions, analyses, and educational content.

Read more here

Read more **here**
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Clue Encyclopedia

We create content around menstrual health, written and fact-checked by clinicians and science writers.

Read more here

Read more **here**
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Hormonal Podcast

A podcast about hormones and how they shape our world, hosted by Rhea Ramjohn.

Read more here

Read more **here**
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Clue webinars for clinicians

Explore Clue webinars and find evidence-based resources for your patients.

Read more here

Read more **here**
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Clue Press

Our work and leadership has been praised by some of the world’s leading publications.

Read more here

Read more **here**
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Clue Privacy Policy

Data privacy is at the core of what we do: we never have, and never will, sell our users’ data.

Read more here

Read more **here**
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Clue Newsletter

Subscribe to our newsletter to get science-backed articles and our latest updates.

Check out what goes on behind the scenes at Clue

About Clue

Clue is a menstrual tracking app, an encyclopedia, a resource for your health, and more. Here are all the posts...

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