– Meet Elina Berglund: a nuclear physicist who will be known as the woman who developed the first natural cycle fertility app that is internationally certified to be as effective as contraception.

“It feels incredibly exciting that there is now an approved alternative to conventional pregnancy prevention methods, and that it’s possible to replace medication with technology,” Berglund told Business Insider in an interview.

The app, called Natural Cycles, was founded in Switzerland by Elina Berglund and her husband Raoul Scherwizl. They created the app as a way to go “beyond contraception,” and to “get to know your body and unique cycles,” according to their website.

“At Natural Cycles, we are all about combining scientific research and mobile tech to empower every woman worldwide with knowledge about her body, menstrual cycle and fertility.”

The app works on a sympto-thermal based system. Using mathematics and advanced technology, the app tracks a woman’s recorded daily temperature through a specific algorithm, which determines fertility, making it a competitive alternative to hormonal birth control and contraception.

This information allows women to know exactly where they are in their cycle, and even considers factors such as temperature fluctuations and cycle irregularities in order to make accurate predictions about ovulation.

Business Insider also pointed to a recent clinical study, which concluded that the Natural Cycles prevention method is just as effective as the pill – without all of the side effects.

However, getting to this point was not easy for Berglund and her husband. Not long after its founding, the Natural Cycles app began to receive some severe investigatory restrictions from the Swedish Medicinal Products Agency.

The organization told the couple that the word “contraception” could not be included in their app. Throughout the ordeal, they also experienced a slash in overall revenue and bad publicity which made the app out to be a source of trickery and scandal.

“At that point, it felt tough. Really tough,” Berglund told Veckans Affärer in 2016, saying “after all, the app had been developed for birth control.”

Despite the hard road, the app just recently received official recognition and approval from Tüv Süd, a German inspection and certification agency. This step not only gives Natural Cycles a step up in legitimacy, but it also proves the effectiveness of natural methods over hormonal medications or contraceptive implants.

In the future, Natural Cycles has big plans to make up for lost time: they are targeting the U.K. with a big marketing sweep, and have their eyes on the United States – if the app gets approved by the FDA.

Right now, the app has over 150,000 users in over 160 countries around the world.

While the Catholic Church teaches that the use of contraception is immoral, because it separates procreation from the sexual act, it does approve of fertility mapping methods, such as Natural Family Planning.

NFP methods, such as the Billings Method or Creighton Model, help women and families achieve pregnancy – or prevent pregnancy, if there is a reason to avoid it – by tracking natural cycles, which is similar to the concept behind the Natural Cycles app.