Health Canada has officially approved birth control app Natural Cycles. Should I use it to prevent pregnancy?

This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis or treatment. Contact a qualified medical professional before engaging in any physical activity, or making any changes to your diet, medication or lifestyle.

Health Canada has officially approved the Natural Cycles birth control app to market and sell itself as a form of birth control.

The app, previously approved as a fertility tracker in Canada, is the only digital birth control and the first app of its kind to obtain a Class II Medical Device License from the federal agency. It markets itself as allowing users to "prevent and plan pregnancy naturally."

According to a release, it has more than three million users globally; it's been cleared by the U.S. FDA since 2018, and in Europe since 2017.

"Our mission has always been to reach as many women as possible and with our latest regulatory clearance from Health Canada, the Natural Cycles app is now accessible to more than 380 million women globally," said Natural Cycles co-founder and CEO Dr. Elina Berglund Scherwitzl, in the release.

But how exactly does this app work, and do Canadian health experts recommend it? Here's what you need to know.

What is 'Natural Cycles' and how does it work?

Natural Cycles is an app and a regulated medical device used to prevent and plan pregnancy, without hormones or side-effects.

Users of the app are asked to measure their temperature overnight or in the morning, log it into the app and confirm their fertility status. If you are not fertile (marked by a Green Day), you don't need to use protection. On a Red Day (meaning fertile), protection is recommended.

"Our hormones cause body temperature to rise around ovulation. By analyzing this we can pinpoint where you are in your cycle," the app explained.

Here's how cycle tracking works in the app, according to Natural Cycles:

1. Your cycle starts on the first day of your period (Green Days)

2. As ovulation approaches you enter the fertile window (Red Days)

3. After ovulation your temperature rises and you are no longer fertile (Green Days)

Dr. Amanda Black, president of the Society of Obstetricians and Gynecologists of Canada, tells Yahoo Canada the app is considered a Fertility Awareness Method (FAM).

"It works by estimating the days on which a woman is likely to be fertile — likely to get pregnant if she has intercourse — based on her body temperature and her menstrual cycle," Black explained in an email, adding there is "a minor rise" in body temperature around the ovulation stage.

"Pregnancy capable people should avoid intercourse (or use condoms) on the these fertile days if they want to avoid getting pregnant."

How effective is the app as birth control?

According to Natural Cycles, the app is 93 per cent effective as birth control with typical use, and 98 per cent effective with perfect use. This means on average, seven out of 100 users will get pregnant in a year.

For its FDA clearance in 2018, Natural Cycles analyzed 180,000 menstrual cycles from 15,000 women to get this data. As explained on its website, typical use "includes all unintended pregnancies and reflects the way a method is used in everyday life," while perfect use "includes pregnancies caused by the failure of the method, and so reflects effectiveness when it’s used perfectly."

Comparing to a hormonal contraceptive pill, the app is on par when it comes to typical use. Planned Parenthood outlined, "If you use it perfectly, the pill is 99 per cent effective. But people aren't perfect and it's easy to forget or miss pills — so in reality the pill is about 93 per cent effective."

The app is also more effective compared to typical use of condoms (87 per cent effectiveness) or the pull-out method (80 per cent effectiveness with typical use).

However, Black explained of all of the contraceptive methods, FAM tends to be "one of the less effective" methods of contraception.

"They tend to work best for women who have very predictable menstrual cycles and who are compliant with avoiding intercourse or using condoms on fertile days and the window around that time," she claimed. "Sperm can live for up to five days prior to ovulation so if you have had intercourse two days prior to ovulation, there is a possibility of getting pregnant."

The OBGYN added IUDs and implants are "much more reliable" as contraceptives.

Is this app recommended as primary birth control for Canadians?

According to Black, it's important for Canadians to be aware of all birth control options — including FAM (such as the app). But, that doesn't mean it's the right choice for everyone.

"For some women, an unintended pregnancy may be devastating for medical or personal reasons (or both). For those patients, a more effective method of contraception might be a much better option," Black said. For those who are more ambivalent about a pregnancy — "if it happens it happens" — less effective methods could work.

Patients who want to avoid hormones can also look into copper IUDs that are effective, and "highly motivated patients with regular cycles" can consider FAM. It's a fair choice for those "who have predictable menstrual cycles" and "want to avoid other methods of contraception."

But, the expert warned with whatever contraception a person chooses, condoms are still recommended to prevent STIs.

While Natural Cycles can be used to prevent pregnancy, Black added it tends to be very useful as a fertility aid, in helping patients conceive.

Yahoo Canada has reached out to Health Canada for comment but did not receive a response in time for publishing.

Let us know what you think by commenting below and tweeting @YahooStyleCA! Follow us on Twitter and Instagram.