Health Library
Health Library

Science and research at Flo

Science and research are key to everything we do at Flo. Find out who we partner with, how to work with us, and how we protect the data of people who use Flo.

How we’re supporting and advancing female health

We know that female health lacks research, so we’re doing our part to build a better future. Flo partners with researchers by providing them with aggregated and de-identified reliable medical data without sharing any personal information from the people who use Flo.

How you can work with us

We’re keen to partner with acclaimed scientists, institutions, universities, and research groups (incl. corporate research groups from different business fields) with in-depth subject-matter expertise and proven contributions to global health and well-being.



Key findings
  • Most study participants reported improvements in menstrual cycle (88.98%) and pregnancy (84.7%) knowledge from Flo app use.
  • Most of the Flo users (73.5%) who used the app to track their pregnancy believe that Flo helped them get pregnant!
  • The key components of Flo app that helped users improve their cycle knowledge and health are the predictions about periods, fertile days, and ovulation, as well as symptom tracking. Meanwhile, reading articles and watching videos helped users learn more about pregnancy.
  • The strongest improvements in knowledge and health were observed in Premium, frequent, and long-term Flo app users.


Key findings
  • 45.2% of users reported missing, on average, 5.8 days of work due to their cycle.
  • 48.4% do not feel supported by their manager, and 94.6% report no workplace benefit regarding their menstrual cycle.
  • The Flo app helped 88.7% of users to feel prepared and more aware of their bodies and 77.6% to feel supported.
Key findings
  • More than 84% of Flo users say the app improved their knowledge about menstrual cycles and pregnancy.
  • 72.2% of users find “reading and/or watching articles and video sources in the app” as the most informative feature of the Flo app.
  • Longer and more frequent Flo Premium users were even more likely to report improved knowledge and health.
Key findings
  • Women in Ukraine reported increased stress after the Russian-Ukranian conflict started. At the same time, they reported pain less often.
  • After the conflict started, women in Ukraine who reported stress were less likely to report pain. This finding is consistent with the phenomenon of stress-induced analgesia.
Key findings
  • Cramps were the most common premenstrual symptom.
  • Somatic, gastrointestinal, and negative mood symptoms were most common in the late luteal phase and least common in the midfollicular phase.
  • Negative mood symptoms decreased throughout the follicular phase, while positive mood symptoms were most common in the late follicular phase.
Key findings
  • Throughout the COVID-19 pandemic, an increase in postpartum depression was found in 36 states of the USA.
  • The increase in postpartum depressive symptoms was greater in the states with fewer deaths from COVID-19 and in the ones where unemployment rates for women were lower in 2020.
Key findings
  • First-time mothers were more likely to report depressive symptoms than mothers with more children.
  • Depressive symptoms were the highest among young mothers (18-24 years).
  • Mothers of twins reported a higher burden of depressive symptoms than mothers of one child.
Key findings
  • The most common PMS symptoms were food cravings (85.28%), mood swings or anxiety (64.18%), and fatigue (57.3%).
  • Physical premenstrual symptoms increased with age.
  • Premenstrual symptoms regarding anxiety and mood remained similar with age.
  • How much premenstrual symptoms interfere with daily functioning every cycle varies across different countries.


Key findings
  • The most common symptoms of polycystic ovary syndrome (PCOS) vary across different countries.
  • Bloating was the most frequently reported symptom among women with PCOS.
  • Women were at least 3 times more likely to have a PCOS diagnosis if they bloat or have high blood cholesterol and glucose.
  • A PCOS diagnosis is more common in women with a higher BMI.


Key findings
  • PCOS is more common as BMI increases.
  • Having hirsutism increases the probability of PCOS by more than 3 times.
  • The most common symptoms of PCOS vary across different BMI categories.
Key findings
  • More than 90% of women typically have a cycle length of 21 to 35 days.
  • Less than half — only 40% — of women have a usual cycle length of 27 to 29 days.
  • Length and variation of the cycle are influenced more by women’s age than the body mass index.
  • Less variation and shorter cycles were found in women older than 40.