Simple.
Safe.
Contraception.
The trackle sensor system helps you identify your fertile window.
It’s simple, safe, and digital: Wear the sensor at night —sync it with the app in the morning — and find out if it’s a fertile day.
trackle - the top-rated choice among cycle trackers
trackle accurately determines your fertile days using the symptothermal method (STM). By analyzing both your core body temperature and cervical mucus, the system reliably detects whether ovulation has occurred.
As the top-rated app, trackle digitizes this proven method and provides you with a reliable foundation — whether you’re looking to practice natural family planning or are trying to conceive.
How trackle Works
- Insert trackle in the evening before going to bed
trackle measures your temperature at night
- In the morning, remove trackle, place it in the box, and enter the cervical mucus quality into the app
The data is sent to the server.
- Check Fertility Status
The server analyzes the data and sends it to your smartphone.
Developed
just for you.
- Accurate measurement results
- No side effects
- Safe Birth Control
- 100% hormone-free
- Developed by a woman
- Scientifically sound
- Made in Germany
- Medically tested
- Reliable Analysis
- Suitable for birth control and trying to conceive
Here's what the experts say
“As a certified Sensiplan® counselor, I help women and couples learn the Sensiplan® method every day. For some, reliable birth control is important; for others, they want to make their dream of having children a reality. trackle is a cycle tracker that women love to use for both purposes.
And what users especially appreciate: The trackle team is always there to help with any questions.”
Adelaide Dechow
Certified consultant for the Sensiplan® method since 1990
“The great thing about technology-based cycle tracking, such as with trackle, is that it makes what’s happening visible: Thanks to the clear symbols, your cycle no longer has to remain a mystery. Understanding your body’s internal processes and closely monitoring them is a key component of reliable birth control and can also contribute to a better understanding of your body.”
Marthe Kniep
Sex educator
“As a certified NFP counselor, I had the opportunity to test the trackle in 2023, and it completely won me over. As a monitoring device, the trackle is particularly well-suited for women who have irregular curves when using a standard basal body temperature thermometer. The trackle makes daily basal body temperature monitoring so much easier!”
Leni Wollgramm
Certified NFP Counselor
Is hormone-free birth control with trackle really safe?
Yes: The symptothermal method, which trackle uses to analyze your cycle, is a very well-researched method and the safest form of natural family planning. With a Pearl Index of 0.4, its effectiveness is even comparable to that of the birth control pill. The method monitors two individual bodily signs that change reliably in a cyclical pattern and analyzes them. No statistics, no calendar, no estimates—just a daily analysis of your own cycle.
Is the trackle cycle computer right for me, too?
Do you think hormone-free birth control won’t work for you because you have an irregular cycle? Or because you work shifts? Or because you wake up at different times? On the contrary —that’s exactly why trackle is perfect for you: Thanks to continuous measurement while you sleep, your temperature readings are always accurate. And since there’s no calendar-based tracking, even irregular cycles aren’t a problem.
Can I wear trackle even during my period?
It’s up to you whether you wear the sensor during your period. We recommend starting to track on the fifth day of your cycle – as a guide, your cycle always begins on the first day of your period. Please continue tracking every night until trackle has reliably determined your ovulation. After that, you can decide whether or not to continue tracking until your next period.
When can I start using trackle after I stop taking the pill?
You can generally start using trackle right after you stop taking the pill, but you should be prepared for the fact that your period and your first ovulation might take a little while to return – your body often needs some time to regain its balance after stopping hormonal birth control. We therefore recommend that you start wearing the sensor on the fifth day of your period and track your cervical mucus daily.
If you need help or information about stopping the pill, you’ll find valuable tips in our Guide: How to stop the pill.
At what point does the analysis become reliable?
What makes trackle special: The results are reliable starting with your very first cycle, since the system isn’t based on past data or predictions. Instead, trackle analyzes your current physical symptoms every day—specifically, your basal body temperature and your observations of cervical mucus.
Since trackle uses the symptothermal method for analysis, you’ll know every day whether you’ve already ovulated in this cycle or not. This means trackle doesn’t require any adjustment period. However, if there isn’t enough data yet, the system will continue to assume you’re fertile.
Da trackle nach der symptothermalen Methode auswertet, weißt Du so jeden Tag, ob Dein Eisprung in diesem Zyklus schon stattgefunden hat oder noch nicht. trackle benötigt also keine Eingewöhnungszeit. Sollten allerdings noch zu wenig Daten vorliegen, geht das System weiterhin von Fruchtbarkeit aus.
When and how does trackle determine ovulation?
trackle is based on the symptothermal method (STM). For a reliable analysis, the system combines two bodily symptoms:
- Core body temperature: The sensor measures this automatically at night.
- Cervical mucus: You enter your observations manually into the app.
The golden rule: An infertile phase is only confirmed once both the temperature rise and the mucus peak have been verified. If a value is missing, the day is considered fertile as a precaution.
Tip: Want to learn more about the method and the reliability of trackle? Then check out our free webinar!
How secure is trackle?
trackle evaluates data strictly according to the rules of the symptothermal method (STM). With a Pearl Index of 0.4, the method’s effectiveness is comparable to that of the birth control pill (both are below 1). Its reliability is also medically recognized: The German Society for Gynecology and Obstetrics (DGGG) explicitly recommends the STM in its official guidelines as a safe, natural method of contraception. These guidelines serve as a sound basis for doctors to provide professional advice.
You can find detailed information comparing different methods here:
Pearl Index and Contraceptive Safety
Does the trackle analysis also take into account the survival of sperm over several days?
There are only about seven days per cycle during which pregnancy can occur. This period consists of the egg’s lifespan (approx. 12–18 hours) and the sperm’s survival time (up to five days).
trackle precisely identifies these fertile and infertile phases according to the rules of the symptothermal method. What makes it special is the double check: By combining the analysis of basal body temperature and cervical mucus, the system offers maximum accuracy.
Scientifically proven: With a Pearl Index of 0.4, the method is comparable to the birth control pill in terms of reliability.
Tip: Want to understand the details? Learn more about analysis and safety in our free webinar!
Is trackle suitable for shift work or restless nights?
Absolutely – the only important thing is that you wear the sensor during a sleep or rest period of at least four hours. The exact time of day doesn’t matter for the measurement. If, in rare cases, a change in your daily routine does affect your readings, you can simply mark this as an interfering factor in the app. The corresponding reading will then be automatically ignored and won’t be included in the overall analysis.
If you have any questions about how to use the device or your results, our support team is always happy to assist you with a personalized analysis of your data.
Can I exchange my trackle? Is there a money-back guarantee?
Since trackle is a certified medical device, we can only accept returns of the sensor in its original, unopened condition within the 14-day cancellation period. Once unpacked, returns are not accepted.
However, we guarantee a 30-month service life from the date of purchase – if your sensor develops a defect during this time, we’ll replace it free of charge.
Want to try trackle first?
Then our subscription is the perfect choice for you: Instead of buying the sensor at full price, you can use it for a small monthly fee covering the app and hardware – with absolutely no hidden costs!
Here’s what makes it special: You can sign up for a subscription that includes a built-in trial period. With the Flex Subscription (which already includes the one-time fee for the trial period), you secure the right to cancel after just six months. If you don’t cancel at least 14 days before the end of those six months, your subscription will automatically transition to the regular 24-month term – it’s that simple.
Do you have any more questions?
Many women are currently looking for a safe, hormone-free alternative to birth control. The symptothermal method is perfect for this—and thanks to trackle’s digital approach, it’s especially easy and convenient—even if you’re new to the topic. If you have any questions, our support team will be happy to help—and on our website, you’ll find plenty of information, videos, courses, and webinars on hormone-free birth control and cycle tracking.