'Replacing guesswork': Irish startup Joii launches AI menstrual monitoring tool
Joii app aims to transform menstrual health tracking with clinically validated, image-based blood analysis
An Irish femtech startup wants to drastically improve how menstrual health is tracked and understood with the launch of its AI-powered mobile app and smart period pads - a world-first innovation now certified as a Class I Medical Device.
Joii, founded by Justyna Strzeszynska, combines a mobile app with specially designed menstrual pads that can be scanned to analyse blood volume and clot size. The startup, which has raised €2.4m in funding to date from Innovate UK, NIHR, and EU EIT Digital, alongside angel investors, says it wants to shift menstrual health from subjective guesswork to quantifiable science.
“For too long, women have been told to just ‘track their period’ without any real tools to measure what’s actually happening,” said Justyna.
“With Joii, we’re changing that. We’re helping people see their periods clearly, for the first time.”
Replacing guesswork
Joii aims to tackle issues like heavy menstrual bleeding, which affects one in three women and is often poorly diagnosed due to vague descriptors like “heavy” or “normal”. By offering objective, visual data that can be shared with clinicians, Joii hopes to speed up diagnosis for conditions such as endometriosis and polycystic ovary syndrome (PCOS) — both of which often go undiagnosed for years.
This is the first product of its kind to measure period volume. Current methods include Alkaline hematin testing, a gold standard used in research labs which is accurate but invasive, complex, and not suited to everyday use; self-assessment in health/period tracking apps, which rely on subjective terms like “light” or “heavy” without data; and weighing used pads, which is both inconvenient and inaccurate.
With Joii, users simply scan their pads using their phone to get an objective, data-backed assessment of both flow and clots, making invisible symptoms visible. The Joii app then uses computer vision and AI to evaluate used pads, providing real-time, clinically meaningful insights — such as blood loss in millilitres and clotting patterns. Knowing real measurement helps to identify issues and earlier diagnosis.
Backed by real-world research supported by the UK's National Institute for Health and Care Research (NIHR), early results suggest the impact could be significant. According to the company, following a real-world evaluation study 62% of users reported improved communication with healthcare providers, and symptom screening efficacy increased by 288%. Menstrual health literacy also rose by 134%.
As well as Class I Medical Device–Certification in the UK, Joii is protected under multiple patents. The company is now partnering with leading institutions to develop predictive models for menstrual conditions, such as endometriosis and polycystic ovary syndrome (PCOS), transforming menstrual blood into a powerful diagnostic tool.
“Joii transforms menstrual blood into clinical insight. By measuring key biomarkers like volume and clot size, we’re turning pads into diagnostic tools and replacing guesswork with real data,” said Justyna.
“This is the first step in recognising periods as measurable, medically relevant events. For users, it’s empowerment. For clinicians, it’s a breakthrough.”
The app is free to download on iOS and Android, while the companion Joii evaluation pads, priced at €6.95, are available online and in selected pharmacies across Ireland.
Retailer Wholefoods Wholesale Ireland is among the early adopters.
“Wholefoods is proud to support Joii Care and their groundbreaking approach to menstrual health,” said Sales Manager Ronan O’Flynn.
“By combining smart technology with a clinically tested menstrual pad, Joii empowers users to measure their period volume and better understand their symptoms.”