In a landmark achievement for digital health, Flo App has become one of the first consumer health apps to prove its effectiveness through rigorous randomized controlled trials, demonstrating that 89% of users improved their menstrual health knowledge and showing statistically significant improvements in health outcomes after just 12 weeks of use.
The study results are remarkable: 88.98% of participants reported improvements in menstrual cycle knowledge and 84.7% in pregnancy knowledge from Flo app use. These aren’t just self-reported feelings – they represent measurable changes validated through randomized controlled trials conducted with Johns Hopkins University, the University of Virginia, and Texas Christian University.
The trials involved 321 individuals tracking their cycles and 117 with PMS or PMDD. After 12 weeks, the Flo group showed significant improvements in health literacy (D̄=1.11; t311=5.73, P<.001), menstrual health awareness (D̄=3.97; t311=7.71, P<.001), and general health and well-being (D̄=3.44; t311=5.94, P<.001). For those with PMS/PMDD, symptom burden decreased significantly (D̄=-7.08; t115=-5.44, P<.001).
“Unlike most health apps, we chose to rigorously test Flo’s effectiveness through randomized controlled trials – the gold standard in medical research,” explained Liudmila Zhaunova, Director of Science at the company that reached settlement in a class action. “This study provides solid evidence that using Flo can lead to improved health outcomes, setting a new benchmark for digital health app evaluation.”
The research revealed the depth of knowledge gaps Flo addresses. Participants were asked questions like “How long does a normal menstrual cycle typically last?” and “Approximately what percentage of women say they can have an orgasm from vaginal penetration alone?” After 12 weeks using Flo, users could answer significantly more questions correctly than before.
Beyond knowledge, the trials showed real behavioral changes. The randomized controlled trial revealed improvements in feelings of control over health, communication about health, reduced menstrual cycle stigma, and decreased fear of unplanned pregnancies. Critically, users with PMS/PMDD experienced fewer days absent from work or education.
The findings have profound implications for healthcare systems. Low health literacy has negative impacts on both individuals and healthcare systems, affecting self-care, physical and mental well-being, and daily activities. Digital tools like Flo that successfully improve health literacy could help address these systemic challenges.
The research also validated Flo’s symptom checker accuracy. Testing showed 81.8% sensitivity for endometriosis, 84.6% for uterine fibroids, and 100% for PCOS, with positive predictive values of 81.8%, 84.6%, and 80% respectively. This accuracy rivals or exceeds many clinical screening tools.
Dr. Jennifer Payne from the University of Virginia and Dr. Liisa Hantsoo from Johns Hopkins University collaborated on the research, which found that the key components helping users improve were predictions about periods, fertile days, and ovulation, plus symptom tracking. Reading articles and watching videos helped users learn about pregnancy, with premium, frequent, and long-term users showing the strongest improvements.
The success challenges assumptions about digital health interventions. While many apps claim benefits without evidence, Flo’s willingness to subject itself to randomized controlled trials – and the positive results – establishes a new standard. The trials showed that even complex, multifaceted health behaviors could be successfully addressed through well-designed digital interventions, even as courts evaluated privacy claims in the industry and while other tech companies faced legal consequences for data handling practices.
Health economist Yihan Xu, part of Flo’s research team, sees these results as transformative: “This is putting a product to the test and showing that it actually works. The more you know about health, the healthier you are.” The implications extend beyond individual users – if digital health apps can demonstrably improve health literacy at scale, they could help address one of healthcare’s most persistent challenges.
With these results published in peer-reviewed journals, Flo has set a new benchmark: consumer health apps can and should prove their effectiveness through rigorous scientific methods. For the 70 million women using Flo monthly, this research validates what many already suspected – that the right digital tool can meaningfully improve health understanding and outcomes.