Natural Cycles review: how it compares with Lulu (different jobs)
Natural Cycles is a temperature-based app cleared by the FDA in 2018 as a method of contraception, with modes for planning pregnancy, pregnancy, postpartum and perimenopause. It's a paid subscription. Lulu does a different job: it's a period and mood tracker that shows how you usually feel in each phase. Lulu is not contraception, and shouldn't replace Natural Cycles for that.
What Natural Cycles is
Natural Cycles is a fertility awareness app. Its algorithm uses your daily temperature (from a basal thermometer, its own NC Band, an Oura ring, WHOOP, some Garmin devices or an Apple Watch Series 8 or later) plus your cycle data to work out which days you're likely to be fertile. In birth control mode it shows a daily status telling you whether you need to use protection.
In August 2018 the US FDA permitted it to be marketed as the first app for contraception. The FDA reported a 1.8% perfect-use and 6.5% typical-use failure rate across clinical studies of more than 15,000 women. Natural Cycles' own listing describes it as 98% effective with perfect use and 93% with typical use. In 2023 its use of Apple Watch wrist temperature also received FDA clearance.
Where Natural Cycles is stronger
- It's contraception. It's cleared by the FDA for preventing pregnancy. Lulu is not, and never should be used that way.
- Temperature science. Daily temperature confirms when ovulation has likely passed, which calendar-only apps can't do.
- Life-stage modes. Birth control, Plan Pregnancy, Follow Pregnancy, Postpartum and Perimenopause, all in one subscription.
- Clinical evidence. It's one of the most studied apps in the category.
- Android support. Lulu is iPhone only.
Natural Cycles vs Lulu
| Natural Cycles | Lulu | |
|---|---|---|
| Main job | Hormone-free birth control and fertility | Period and mood tracking |
| Contraception | Yes, cleared by the FDA | No. Not a method of contraception |
| Data it needs | Daily temperature from a thermometer or wearable | Period dates and a one-tap daily mood check-in; optional Apple Watch temperature |
| Mood | Symptom tracking | Shows how you usually feel each cycle day, heads-up before harder days |
| Perimenopause | NC Perimenopause mode | Perimenopause mode |
| Pregnancy and postpartum | Yes | No |
| Partner sharing | Not covered here | Partner sync: phase, plus mood forecast if you opt in, never symptoms or notes |
| Account | Yes | No account; cycle data stays on your iPhone |
| Price model | Paid subscription (monthly or annual) | 3-day free trial, then yearly Lulu Plus |
What to know before choosing Natural Cycles
- It takes daily discipline: consistent temperature readings and correct use. Typical-use effectiveness is lower than perfect use.
- It doesn't protect against STIs.
- Hormonal birth control and some conditions affect temperature-based methods. Natural Cycles says people on hormonal contraception can't use its birth control mode.
- It's a paid subscription; check current prices and auto-renewal terms in the App Store.
Who each suits
Natural Cycles suits you if you want a hormone-free method of contraception, or detailed temperature-based fertility tracking, and you're happy to measure temperature daily. Lulu suits you if you want to understand your moods and energy across your cycle, get a heads-up before harder days and share that with a partner, with no account. Some people use both: Natural Cycles for contraception, Lulu for mood.
If you're choosing contraception, talk to a doctor, nurse or pharmacist about which method fits your health and life. Calendar-based "safe days" in ordinary period apps are not reliable contraception. See a doctor promptly if you have a missed period and could be pregnant, severe pelvic pain, or unusual bleeding.
Read why ordinary apps can't tell you "safe days" in our safe days explainer, and see Apple Watch period trackers for how wearables fit in.
Frequently asked questions
Is Natural Cycles effective?
The FDA reported a 1.8% perfect-use and 6.5% typical-use failure rate in clinical studies. Effectiveness depends heavily on correct, consistent use.
Can I use Lulu instead of Natural Cycles for birth control?
No. Lulu is not a method of contraception. Its fertile window is an estimate only.
Does Natural Cycles work with Apple Watch?
Yes. It can use overnight wrist temperature from Apple Watch Series 8 or later and Ultra models.
What is a Natural Cycles alternative for mood tracking?
If you don't need contraception and want to understand your moods, Lulu, Clue and Flo all track mood; Lulu builds its main feature around it.
Sources
- STAT: FDA clears Natural Cycles app as contraception (Aug 2018)
- FDA: De Novo classification decision for Natural Cycles (DEN170052)
- Natural Cycles on the App Store (US)
- Natural Cycles: Perimenopause
This page is for information only and isn鈥檛 medical advice. If something worries you, please talk to a doctor.
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