As a 35-year-old woman who’s been very intentional about family planning, I want to share my experience using Natural Cycles—first to avoid pregnancy and then later as a tool to help me conceive. If you’re curious about how it works, how accurate it is, and whether it’s worth trying, here’s everything I wish I’d known before I started.

What Is Natural Cycles?

Natural Cycles is a fertility awareness-based app that uses your daily basal body temperature (BBT) and optional LH testing to predict your fertile window. It’s the first FDA-cleared birth control app, and it’s also CE-marked in Europe. You can use it in “Prevent” mode to avoid pregnancy or “Plan” mode to conceive. It works by analyzing your unique cycle patterns to predict ovulation and let you know which days you’re fertile.

In short, it’s a hormone-free, data-driven alternative to traditional birth control or fertility tracking.

How It Works

Each morning, you take your temperature with a basal thermometer (or sync it with an Oura Ring, more on that below). The app logs your data, and based on an algorithm, tells you if it’s a “red day” (fertile, use protection) or a “green day” (not fertile, unprotected sex is okay). When you switch to “Plan” mode, it helps you pinpoint ovulation and your most fertile days to increase your chances of conceiving.

You can also input LH test results, cervical mucus observations, and note symptoms, which the app uses to refine its predictions over time.

Cost

Natural Cycles offers two subscription plans:

There’s also the Natural Cycles with Oura Ring option, where you don’t need to take your temperature manually. If you already have an Oura Ring Gen 3, you can integrate it. If not, Oura Rings start at $299.

FDA Approval & Safety

Yes, Natural Cycles is FDA-cleared for use as a form of contraception (since 2018). This means it met the agency’s standards for efficacy and safety. It’s also backed by clinical studies, which gives it more credibility than the average fertility tracking app.

It’s important to note that FDA-cleared ≠ foolproof. Like any method, it has a failure rate.

Effectiveness: Real-World Failure Rate

Natural Cycles has two reported failure rates:

• Perfect use: 1.0% (1 out of 100 women will get pregnant in a year using it perfectly)
• Typical use: 6.8% (real-life usage, including occasional missed temps or unprotected sex on fertile days)

In my experience, as long as I was consistent with daily temperature tracking and honest about protection on red days, it felt manageable. That said, if you’re someone who forgets easily or doesn’t like routine, this might not be your best option.

Natural Cycles vs. Oura Ring: Is the Accuracy the Same?

When I started, I used a basal thermometer, which took about 60 seconds each morning— and I honestly was NOT great at it. You have to do it before you even get out of bed to pee.

When Natural Cycles announced integration with the Oura Ring, I was intrigued as my midwife had previously recommended wearables for tracking BBT (basal body temp).

NOTE: You can also use an apple watch too

The Oura Ring tracks nightly temperature trends, meaning you don’t have to do anything in the morning—just sync the data. For me, that was a game-changer.

As for accuracy, Natural Cycles states that the Oura integration is equally accurate in predicting fertile days. They adjusted their algorithm specifically for Oura data. I compared both for a couple of cycles, and honestly, the predictions were nearly identical.

That said, Oura is more passive—great for people who want less friction, but the upfront cost is higher.

Do Doctors Recommend Natural Cycles?

Here’s the nuanced answer: Some do, some don’t.

Natural Cycles is FDA-cleared, which means many OB/GYNs acknowledge it as a legitimate option. However, some doctors still prefer recommending hormonal birth control or IUDs, especially for women under 35 who aren’t ready for kids anytime soon.

When I discussed it with my doctor, she said it could be a reasonable choice for someone highly motivated and consistent, but emphasized the importance of understanding the failure rate—especially compared to more traditional methods.

For trying to conceive, my doctor was fully supportive. She noted that fertility awareness is a great way to become more in tune with your body, and the app’s data can be helpful if you end up needing to consult a fertility specialist.

My Experience: From Avoiding Pregnancy to Trying to Conceive

When I first started using Natural Cycles, I was looking for a hormone-free alternative to the pill. I was skeptical at first, but after a couple of months of tracking, I loved feeling more connected to my cycle.

We are getting ready to start trying again and I love that I’ll just need to switch to “Plan” mode in the app. It feels like a seamless transition—same data, different focus.

Final Thoughts: Would I Recommend It?

Yes, with caveats. If you’re looking for natural, non-hormonal birth control and are willing to commit to daily tracking (or invest in an Oura Ring), Natural Cycles is a great option. It’s not 100% foolproof, but it gives you control and insight into your body. And we haven’t had an unexpected pregnancy since using it (I had my last kid in 2021 and started using it after).

If you’re trying to conceive, it’s a fantastic tool for understanding your fertile window without overcomplicating things.

For both purposes, it’s empowering—as long as you’re clear on your goals and realistic about the commitment.

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