“I was absolutely amazed at the amount of research and data that has gone into the creation of the Natural Cycles app.”Dr. Karen TangGynecologist, Natural Cycles Medical Advisor
6 reasons why millions of women trust Natural Cycles for hormone-free birth control.
TLDR: the only FDA-cleared birth control app. 93% effective with typical use, 98% with perfect use, and no side effects because there is nothing to take.
By Jennifer GrayWriter, Cycle Matters by Natural Cycles · Updated September 2026
Natural Cycles vs. the pill
The pill
Hormones
✅None
Synthetic estrogen and progestin
Side effects listed
✅None
Mood changes, lower sex drive, among others
Daily routine
😴Wear a device to bed
A pill at the same time every day
How you get it
📲Online, no prescription
Prescription
Effective, typical use
✅93% (98% perfect use)
93% (over 99% perfect use)
Shows you your own cycle
🌅Every morning
❌No, ovulation is suppressed
Your partner can follow your day
👫Partner View
❌No
Effectiveness is typical use over one year.1 Pill details from Natural Cycles' own guides.2, 3
1. No side effects, because there is nothing to take.
Hormonal methods put something in your body and you live with what it does. Natural Cycles reads your temperature and tells you which days you need protection.
2. It is FDA-cleared birth control, 93% effective with typical use.
The only birth control app cleared by the FDA, for 8 years now. Each morning you get one answer: a Green Day, or a Red Day when you use protection.
3. You learn what your body is doing across your whole cycle.
Your temperature rises after you ovulate and falls before your period. The app reads that shift in your own data, so it confirms where you are instead of guessing.
4. It works with the wearable you already own.
Where you measure
WristFingerWrist
When you measure
OvernightOvernightOvernight
Syncs on its own
YesYesYes
Effectiveness: the same on every device.93% with typical use, 98% with perfect use.1 Also works with Garmin and WHOOP.
Every device is just as effective. Wear it to bed, the app reads your temperature while you sleep, and your answer is waiting when you wake up.
5. Your partner can see your day too, and you decide what he sees.
Partner View in the Natural Cycles app.
Partner View puts your Red or Green Day, your ovulation status and your predictions on his phone the same morning they land on yours.
6. Millions of women already use it.
Natural Cycles has helped more than 6 million people plan or prevent pregnancy,6 and it is a regulated medical device rather than a period tracker.
From women who switched
Dr. KataraNatural Cycles user“Has got to be THE best natural birth control on the market. 10/10 recommend!”
BethanyNatural Cycles user“I’ve experienced significantly less pelvic pain... and our intimacy couldn’t be better.”
MichelleNatural Cycles user“I feel empowered knowing about my body’s natural processes.”
Backed by named doctors
“For far too long women have had few dependable, hormone-free birth control options.”Dr. Barbara LevyOB-GYN and Menopause Provider, Natural Cycles Medical Advisor
“Natural Cycles has created a birth control option for women that is a definite game changer.”Dr. Jessica ShephardOB-GYN and Menopause expert, Natural Cycles Medical Advisor
NC° Band included with annual
Start on the annual plan and the NC° Band comes with it.
The Band measures your temperature overnight and syncs on its own. It is included free with the annual plan. No prescription, and FSA and HSA eligible.12
Get startedOne-year warranty on the Band
30-day returns on the Band
One subscription, five modes: Birth Control, Plan Pregnancy, Follow Pregnancy, Postpartum and Perimenopause. NC° Secure data protection included.8, 11
Questions people ask first
Can I start while I am still on hormonal birth control?
No. Hormonal birth control affects your temperature, and it generally works by stopping ovulation, so you do not have an actual cycle while you are on it. Because Natural Cycles reads temperature to work out your fertility status, you need to come off hormones before you start. Natural Cycles publishes a guide on when and how to start after hormonal birth control.
My cycles are irregular. Does it still work?
Yes, and it is just as effective. The app accounts for cycle irregularity, temperature fluctuations, recent use of hormonal contraception, variation in ovulation day, sperm survival and several other factors, so the result is built around your cycle rather than an average one. It can also flag atypical or irregular patterns for you to raise with your healthcare provider.
What exactly does my partner see in Partner View?
Once you turn it on and invite them by email, they see your Red and Green Days, your ovulation status, your predictions, the temperatures you have added along with the reason any temperature was excluded, and your period and spotting entries. Everything else is optional and off unless you switch it on: emotions, which covers PMS and moods, plus pain, skin, notes, sex, sex drive, ovulation tests and pregnancy tests. You also pick a sharing start date, and anything logged before that date never appears on their phone.
How is my data protected?
Every subscription includes NC° Secure, the privacy protection program. It uses encryption and pseudonymization, so identifying details such as your name or email are replaced with codes and your data cannot be linked directly back to you without extra information. You can also turn on Go Anonymous, which separates your personal identifying information from your fertility data so that nobody, including Natural Cycles, can link the two. You can request deletion of your data at any time. Natural Cycles is a regulated medical device designed to comply with GDPR and with FDA cybersecurity requirements, and because it is a paid subscription the company does not need to make money from your data the way free apps do.
Sources
- Typical-use effectiveness: Contraceptive Technology, Table 5-2, 22nd Edition, as published by Natural Cycles. Natural Cycles is 98% effective when used as intended and 93% with typical use. No method is 100% effective.
- Natural Cycles, Cycle Matters: "7 Hormonal Birth Control Methods and How They Work" (pill and hormonal IUD: hormones, how you get it, effectiveness, side effects noted).
- Natural Cycles, Cycle Matters: "Non-hormonal birth control options: Effectiveness rates and how to choose" (condoms, and the Natural Cycles pros list: no side effects, no monitoring period).
- Natural Cycles Research Library: survey of 2,674 new users who had been on hormonal birth control in the previous year (62% side effects, 27% suspected, sex drive 69%, mood 64%).
- Natural Cycles User Survey, February 2024, more than 2,200 users, as published on naturalcycles.com/reviews (99% happy about the switch, 98% understand their body better, 9 in 10 feel healthier).
- naturalcycles.com/birth-control, naturalcycles.com/reviews and the homepage stat block (6+ million users, FDA-cleared for 8 years, 30 published studies, 35+ countries, irregular cycles).
- naturalcycles.com/devices, /apple-watch, /promo-code FAQ, and Natural Cycles' own "Which device is right for you?" comparison.
- naturalcycles.com/shop/nc-b1-band (NC° Band specs; included with a new annual subscription).
- Natural Cycles help center, Partner View articles (what is shared automatically, what is optional, invitations, start date, switching off).
- naturalcycles.com/reviews and the App Store listing (4.8, 58K+ ratings, 6,500+ verified 5-star reviews, medical advisor quotes, named user reviews).
- Natural Cycles Limited Warranty and Returns Policy (NC° Band: one-year limited warranty, 30-day returns).
- naturalcycles.com/reviews, "More reasons to choose NC°": covered by most US insurance providers, FSA and HSA eligible; no prescription required per naturalcycles.com/birth-control.
You must be over the age of 18. Does not protect against STIs.
FDA Cleared
Natural Cycles is 93% effective with typical use, 98% effective with perfect use. No method of contraception is 100% effective. Natural Cycles does not guarantee that you cannot get pregnant, it only informs you whether and when you can become pregnant based on the information that you enter into the application.
Natural Cycles is available as a method of birth control in the US and territories; Canada; United Kingdom; Ireland, France; Germany; Netherlands; Luxembourg; Belgium; Spain; Portugal; Austria; Switzerland; Italy; Latvia; Lithuania; Malta; Estonia; Sweden; Denmark; Norway; Finland; Iceland; Bulgaria; Czech Republic; Hungary; Poland; Romania; Slovakia; Greece; Cyprus; Croatia; Slovenia; Montenegro; Singapore; Australia; Brazil. Outside these countries listed, Natural Cycles is intended to be used for fertility monitoring.