Elina Berglund isn’t your typical company cofounder. Originally a particle physicist, Elina was unimpressed with the birth control options offered to women, so she went about creating her own. Today, she is the CTO and cofounder of Natural Cycles, the only FDA approved digital birth control.

Below, Elina shares how she created Natural Cycles, how she transitioned from physics to business, and the best advice she’s ever been given.

What whitespace did you see in the birth control industry, and how did you go about filling it?

Natural Cycles came out of a personal need of an effective, easy-to-use, hormone free birth control method. When I did not find such a product on the market, I started reading up on the scientific literature on how the basal body temperature can indicate when you ovulate and hence when you are fertile and not. Using my knowledge from particle physics (I was currently working at CERN on what would lead to the Higgs discovery in 2012), I started crafting an algorithm that gives a green day if there is no risk of fertility that day and a red day if one needs to use protection in order to prevent pregnancy.

Not long after I realized what a huge unmet need this is among women worldwide for such a hormone free birth control option and that many women don’t use any birth control at all, or very non-effective methods such as the rhythm method, since they haven’t found a method that suits them.

How does Natural Cycles work? What sets it apart from other birth control options?

Natural Cycles comes in the form of an app and a basal thermometer. The user measures her temperature in her mouth when she wakes up in the morning and enters it into the app. Then, the algorithm is run in the background and returns a red day if she needs to use protection that day or a green day if she definitely is not fertile that day.

Natural Cycles is the only FDA cleared, digital birth control method. The method has been shown repeatedly in several studies published in peer reviewed journals to be 93% effective under typical use and 98% effective under perfect use (which is when the user does use protection when the app gives red days).

Natural Cycles fills the void in the family of birth control methods for women who are looking for an effective and non-invasive hormone free method. It also has the additional benefit of being able to be used for planning a pregnancy. As our average user is 30 years old, we often see women first use the app to prevent pregnancy for a few years, until they are ready for the next step and then they on average get pregnant quite quickly as they’ve by now really learned how their unique cycle and body works.

Why was it important for you to create Natural Cycles?

I think it is really important to provide women with different types of birth control options as there is no one size fits all when it comes to birth control, as different women have different needs and which also often changes throughout the reproductive lifetime.

Then, I also feel that women’s health is an under-researched and under-developed area in general, and I’m happy to make a contribution by developing the first FDA cleared birth control app, but hope to contribute even more in the future.

Your background is in physics, and you even worked on a project that received a Nobel Prize. How did you make the shift from physics into business and the tech industry?

Yes, in some sense it is very different but in another sense very similar. I still work with data and research and use programming and advanced statistics as the main tools, just with a different purpose. Then on the other hand, the business and the tech world is quite different from the world of physics and academia, so I do think I’ve learned quite a lot in the last years by changing paths.

You cofounded Natural Cycles with your husband. What has it been like being married to your business partner?

Yes, I did! I think it has mainly been a source of strength as we are almost always very aligned, and it is amazing to be able to share such a passion, which Natural Cycles is to both us. There are of course a few down sides as well, for instance it is really hard to stop talking about work in the late evening when it would probably be better for us to think about something more relaxing.

“One should always consider: ‘What is the worst that could happen, and how likely is that?’”

What is the best advice you’ve ever been given? What’s the best piece of advice you have to share?

My dad often said that “People too often let fear control their lives.” I think he is right in the sense that we often take decisions based on a too risk-averse profile, especially women.

One should always consider: “What is the worst that could happen, and how likely is that?” This is what I thought about when giving up my career in physics and not having a salary for a while when creating Natural Cycles. I thought that I had enough savings to get by for a while and hence the worst case that can happen is that Natural Cycles does not take off, but I’ve then still learned about how to develop an app, and I might end up getting a job at Google instead.

How do you hope female contraception will evolve in the future? Where do you see the industry going?

Well, I hope there will also be more options for male contraception, although I think it’s unfortunately unlikely in the nearer future.

I hope female contraception will also keep evolving, of course, but I think there is an increased need for more solutions driven by the tech industry to compensate for that the pharmaceutical industry unfortunately has cut back funding in this area.

Here in the United States, female sexuality is still pretty taboo. How do you see your company combating that stigma?

We do try to spread knowledge more generally about birth control, female sexuality, and how the women’s reproductive system works. We’ve seen that unfortunately there is a big education gap when it comes to these topics. We are trying to address that, and we do see a huge interest from our users’ side in understanding their bodies better and everything around it, which is exciting.

You have a daughter, what are the biggest lessons you hope to teach her?

Oh, so many things of course! Just like I was at her age (she is 4), she is already curious about so many things about how nature and the universe works. I am trying to spark more of that interest by answering all her questions and discussing with her.

What’s next for you? What’s next for Natural Cycles?

We’ve moved to NYC last fall, following the FDA clearance to build up a team here as we believe that the US market is and will be very important to us going forward. It’s very exciting to be here and learn about what kind of user is ideal for us here and how to best reach her.

We are also expecting a little baby brother next week, so that’s of course quite a big thing for us :)