Warnings are growing about the privacy risks for women using menstrual tracking apps.

The popularity of menstrual cycle tracking mobile apps, promoted as tools for personal empowerment and self-awareness, has raised increasingly serious concerns among privacy experts, digital rights advocates , and feminist organizations in recent years, particularly since the debate in the United States over the criminalization of abortion and the role that personal data could play in legal proceedings has intensified.

Although initially hailed as technological advances that allow millions of women to more accurately manage aspects of their reproductive health—from predicting ovulation to tracking premenstrual symptoms or hormonal disorders—these apps have come under increasing scrutiny following revelations about opaque data practices and potentially punitive uses of the information they store.

Along these lines, a new report by the Minderoo Centre for Technology and Democracy at the University of Cambridge, which among other functions investigates the impact of technology on democracy, warns that women who use these types of platforms face "real and alarming risks to their privacy and security" derived from the economic model on which many of these tools are based. The study highlights that personal information entered into these applications—from menstrual cycle length to data on sexual relations, medication use, contraceptive use, diet, exercise, or hormone levels—can be systematically collected and sold on a large scale, often without clear consent and with little regulatory oversight.

"Data about who is pregnant, or who wants to be, has become some of the most coveted data within the digital advertising ecosystem," the report notes, warning that this type of information is routinely used to create extremely detailed consumer profiles.

According to the researchers, many women download these apps when they are trying to conceive, which often coincides with an abrupt change in their purchasing habits—for example, they stop buying contraceptives , start looking for prenatal vitamins, or become interested in content about maternity, fertility clinics , or maternity clothes—a pattern that advertisers can exploit for commercial purposes. Dr. Stefanie Felsberger, lead author of the study , denounces that “menstrual cycle trackers are presented as tools to empower women and reduce the gender health gap,” but in reality, “the economic model that underpins their operation is based on the commercial use of data, selling information about users and their behavioral patterns to third parties for profit.”

The report states that the data collected by these apps is "fine-grained, granular, and extremely valuable," and that its circulation on intermediary networks, often invisible to the end user, not only fuels the targeted advertising economy but also poses "severe security risks." In the wrong hands, the researchers warn, this information could be used to discriminate against women when purchasing health insurance, limit their employment opportunities, or even be used as a tool of control in domestic violence situations.

Gina Neff, executive director of the Minderoo Centre, sums it up clearly: “There are real and alarming risks to women’s privacy and safety as a result of the commodification of data collected by these apps,” adding that “women deserve better than to have their menstrual information treated as consumer data.”

The study also highlights the rapid expansion of the phenomenon: the three most popular tracking apps together have accumulated more than 250 million downloads worldwide, making this market a vast source of intimate data. Faced with this situation, the report calls for better governance of the so-called "Femtech" sector and urges the implementation of stricter data protection measures, as well as meaningful consent mechanisms. It also raises the need for the country's health authorities to develop public alternatives to commercial apps that prioritize the interests of users over profit.

Concerns about the punitive use of data are not unfounded. In the United States, for example, since the overturning of the ruling guaranteeing the federal right to abortion, many women began deleting these apps from their phones, fearing that their records could be used in criminal investigations in states where abortion has been banned. As criminal defense attorney and former prosecutor Sara Spector explained to Sky News, "If they're trying to prosecute a woman for having an illegal abortion , they can issue a subpoena for any app on her device, including menstrual trackers."

This judicial dimension, although linked to the US case, has served to alert activists and legislators in other countries, such as the United Kingdom, to the lack of safeguards under which many of these tools operate. Despite stricter European legislation on personal data protection, not all applications fully adhere to these standards , especially those developed outside the European Economic Area.

The Minderoo Centre's research concludes that, without clear regulation and without alternatives that prioritize users' health and autonomy, the expansion of these apps represents a structural risk to the digital privacy of millions of women. Its warning is direct: the apparent technological neutrality with which these private platforms present themselves should not obscure the fact that their operating logic is based on the extraction of intimate data for commercial exploitation. In the words of the report, "Menstrual cycle tracking, as it is currently presented, is not a tool for empowerment, but rather a means for the accumulation and mass commercialization of sensitive data."