Natural Cycles, which until yesterday was marketed as a fertility tracking app, has announced today that it it is the first app to be certified as a method of contraception.

The Stockholm, Sweden-based startup, which launched in 2014, currently has 150,000 users in 161 countries. It bases its research on women’s body temperatures to determine peak fertility. The woman takes her temperature every morning, feeds the data into the app, and waits for the result — a green light indicates that it is safe to have unprotected sex and a red light indicates a risk of getting pregnant.

“We’ve always wanted to be a contraceptive product,” said Raoul Scherwitzl, CEO and cofounder of Natural Cycles, in an interview with VentureBeat. “This is a huge step for mobile apps, because if you want to impact people’s lives, then there’s no way around regulations.” The app guarantees protection up to 99.5 percent (5 women out of 1,000).

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Unlike the U.S. Food and Drug Administration (FDA), which performs its own inspections and approvals, European regulators appoint auditing firms to carry out certifications. In this case, the regulating body was the UK’s Medicines and Healthcare products Regulatory Agency (MHRA), which appointed Tüv Süd, a Germany-based auditing firm, to perform the inspection and certification.

The Natural Cycles app joins a range of medical products that have been clinically tested and approved to achieve an IIb classification. This is good news for women who want a natural, non-invasive alternative to the pill, intrauterine devices (IUDs), and condoms. The app is available on the App Store for the iPhone, Apple Watch, and iPad, as well as Google Play Store for Android devices.

There are a number of fertility- and period-tracking apps out there like Glow, Clue, and Ava, but Natural Cycles claims to be the world’s first app to be certified as a contraceptive. It’s a big step for the femtech sector, which is striving to disrupt women’s health.

Natural Cycles has raised a total of $8 million in venture capital from Sunstone Capital, Bonnier Media Growth, and e.ventures. The company currently has 20 employees.