Cycle apps can help with contraception or family planning – at least that’s what many users hope. Stiftung Warentest examined 21 apps and only considers five of them to be reliable.
Cycle apps are actually intended to provide reliable information about fertile and infertile days or at least help you better understand your own cycle. But relying on digital calendars can be risky: “Many fail in our test,” writes Stiftung Warentest.
Half of the cycle apps fail the test
Eleven of 21 cycle apps tested failed the test with a grade of “poor”. The reasons: their way of working. According to Stiftung Warentest, these apps work mathematically, so they work on the assumption that each cycle lasts exactly 28 days and ovulation occurs on day 14. In some cases, they calculate forecasts for the coming cycles from the average values of past cycles.
But: “It doesn’t fit with real life,” complain the testers. Because cycle lengths can vary from month to month. Anyone who relies solely on this mathematical approach could seriously make a mistake – and risk an unwanted pregnancy.
Five additional apps are only “sufficient”. Only five cycle apps in the test achieved a “satisfactory” test rating and are therefore recommended to a limited extent.
In addition to the measurement method, the testers criticize deficiencies in data protection in many apps – such as the password requirements and number of permitted login attempts – and in the terms and conditions. Some providers did not want to respond to inquiries about the personal data stored.