University of Cambridge report warns period tracking apps pose privacy and safety risks
University of Cambridge researchers reported that period tracking apps collect and sell sensitive reproductive data at scale to advertisers and third parties, creating potential risks for women including employment discrimination, health insurance denial, and misuse of intimate personal information.
What happened
The University of Cambridge's Minderoo Centre for Technology and Democracy published a report on June 10, 2025 warning that period tracking apps collect extensive personal data including information on users' exercise, diet, medication, sexual preferences, hormone levels and contraception use that can be 'sold at scale' and used for consumer profiling.
The report states that data on pregnancy is 200 times more valuable than data on age, gender, or location, and that this reproductive intent data has emerged as one of the 'most sought-after' categories in digital marketing.
Reported impact
Women using period tracking apps face 'real and frightening privacy and safety risks', with menstrual data potentially misused for health insurance discrimination, impacts on employment opportunities, domestic abuse, cyberstalking, denial of job opportunities and healthcare, or in the US context, making abortions tougher.
The apps' top three providers have surpassed 250 million global downloads, and the data is shared with an 'inextricable net of third parties', leaving users vulnerable to targeted advertising and data exploitation.
Index analysis
Dr Stefanie Felsberger, lead author of the report, noted that most women surveyed in Austria did not think their period data was private and were unaware that the data is extremely valuable commercially.
The researchers describe period tracker apps as a 'lucrative business' due to their access to 'extremely valuable and fine-grained user data' that poses both commercial exploitation risks and severe security risks for users.
Governance controls
The authors recommend enhanced data security, meaningful consent options within apps, and for public health bodies like the NHS to create non-commercial alternatives for cycle tracking.
Classification
Sources and evidence
This record was researched and written by the Index, based on the following original reporting.