From particle physicist to Natural Cycles founder: Meet Dr. Elina Berglund-Scherwitzl

Today, I want to share my story. From my own birth control journey to building Natural Cycles, growing my family, and how my experiences have shaped the products we create for our Cyclers around the world.

Growing up in Sweden, I was fascinated by science. I wanted to understand how the universe worked: the planets, the stars, and how everything fit together. My parents were scientists and entrepreneurs, a combination that made them deeply curious and ambitious. Looking back, I can see how much those early years shaped who I am today.

When I left home for university, studying physics felt like the obvious choice.

My birth control journey

Maybe I was unusual, a female physicist in a male-dominated field, but in many ways, I was just like so many trying to find a birth control method that felt right for them.

Like millions of women, I started with the pill. And like many, it simply didn’t work well for me.

After speaking with my doctor, I switched to the implant: a small device placed in the arm that slowly releases hormones over several years. It suited me much better, and I used it for almost a decade.

In my early twenties, I met my husband, Raoul, while studying in the US. He was a physicist too, and we immediately bonded over our shared curiosity about the world and our love of science.

A few years later, we got married and moved to Geneva, where I completed my PhD and began working at CERN, the European Organization for Nuclear Research. There, I worked on the discovery of the Higgs boson particle — groundbreaking research that later contributed to the Nobel Prize in Physics.

At the same time, Raoul and I had started talking about our family. We knew we wanted children in the future, and I began thinking about coming off hormonal birth control. But when I looked around for hormone-free alternatives we could use in the meantime, I couldn’t find a solution that felt right for me.

That curiosity led me to fertility awareness methods and the science behind basal body temperature and the menstrual cycle. The more I learned, the more fascinated I became. I started measuring my temperature every morning and recording my own data to better understand my cycle and identify when I was fertile.

Learning to build an app

After the Higgs boson discovery, my time at CERN was coming to an end. While I still loved physics, I felt pulled toward a new challenge: applying the scientific methods I’d used in research to reproductive health.

In those early days, I wasn’t just the founder of Natural Cycles, I was also Cycler number one (and employee number one)! I built the algorithm, coded the app, answered customer support emails, and even designed our first website myself.

I already had coding experience from my work at CERN, but building an app from scratch was completely new territory.

I wanted to create something that could work not only for me, but for other women, too. I built the first version of the Natural Cycles algorithm using data from our earliest users (including myself!) alongside published cycle research from thousands of women.

What emerged was something simple, but powerful: an app that could help people better understand their cycles and know their daily fertility status.

For me, it felt obvious that we had uncovered something important: a hormone-free birth control option designed to give people more knowledge about their bodies and more choice in their reproductive health.

Raoul shared my passion for women’s health and my excitement about building something new together. In 2014, we moved to Stockholm and officially launched Natural Cycles in Sweden.

Growing our business and our family

After successfully using Natural Cycles as birth control, we made the decision to start a family and switched to NC° Plan Pregnancy. We were fortunate to conceive our daughter straight away, and becoming pregnant deepened my connection to women’s health even further.

I remember thinking how surprising it was that so many of us move through major reproductive milestones without truly understanding the biology of our own bodies.

As Natural Cycles grew, so did our mission.

In 2018, Natural Cycles became the first birth control app to receive FDA clearance in the US, building on our years as an established option in Europe. It was a huge milestone — not just for us as a company, but for digital women’s health more broadly.

That same year, our family moved to New York City.

Around that time, we started trying for a second child. This time, the experience was very different. After experiencing two miscarriages, I came to understand how isolating and emotionally complex pregnancy loss can be.

When we welcomed our son in 2019, those experiences stayed with me.

As I moved through different stages of reproductive health, Natural Cycles evolved alongside me. My experience with pregnancy loss helped inspire NC° Recovery, designed to support people through a vulnerable and often lonely time with a gentler app experience and tailored content.

A few years later, we launched NC° Postpartum to support users after childbirth as they navigate recovery, hormonal changes, and the transition into life with a new baby.

Understanding perimenopause

In my forties, I began noticing subtle changes in myself. I wasn’t sleeping well, and I found myself feeling more anxious than usual. I had always associated perimenopause with symptoms like hot flashes and night sweats, so at first, I didn’t recognize what I was experiencing. But as I learned more, I realized these emotional and cognitive shifts can also be early signs of perimenopause.

In fact, it was through trying our NC° Perimenopause assessment myself that I recognized I was already entering this new stage.

That realization reinforced something I’ve felt throughout my journey in women’s health: too many people are expected to navigate major hormonal transitions without the tools, education, or support they deserve.

We built NC° Perimenopause to help people better understand these changes through cycle insights, assessments, tailored content, and expert guidance — all grounded in science and designed to help users feel informed and supported through this stage of life.

Looking ahead

Since launching Natural Cycles in 2014, we’ve continued to evolve alongside our users and expand what’s possible in reproductive health.

From new ways to measure temperature overnight to launching new modes that support different life stages, innovation has always been at the center of what we do. We’ve now published 30 scientific studies and built a team of passionate scientists, designers, engineers, and healthcare experts — all committed to advancing women’s health.

And yet, after more than a decade of creating Natural Cycles, I still feel like we’re only getting started. Women’s health remains one of the most underserved areas in healthcare, and I’m incredibly excited about what’s ahead — both for Natural Cycles and for the future of reproductive health innovation more broadly.

Thank you for taking the time to read my story and for being part of the Natural Cycles journey. If you’d like to try the Natural Cycles app, use my referral link to get 20% off our annual subscription, plus a free NC° Band.