How effective is NC° Birth Control?

NC° Birth Control is 93% effective with typical use and 98% effective with perfect use. Let's unpack what effectiveness means and how it varies between common methods.
A top view of several birth control methods next to each other. Natural Cycles, Hormonal IUD, Copper IUD, a pack of contraceptive pills, a male condom, a NuvaRing and an representation of the pull out method.

What do we mean by effectiveness?

Birth control effectiveness is calculated using the Pearl Index (PI). This represents the number of unintended pregnancies that occur when a group of 100 women use a particular method of birth control for a year.  

Each birth control method has two categories of Pearl Index: typical use and perfect use.

Understanding typical & perfect use

An illustration with two hands and a target to represent typical use.

Typical use

Includes all unintended pregnancies and reflects the way a method is used in everyday life.

An illustration with one hand, a target and sparkling stars to represent perfect use.

Perfect use

Only includes pregnancies caused by the failure of the method, and so reflects effectiveness when it’s used perfectly.

Here's an example:

A method has a typical use Pearl Index of 7 (meaning 7 women in 100 get pregnant during one year of use). When birth control effectiveness is shown as a percentage, we look at the number of pregnancies that did not happen. So in this case, 93 out of the 100 women in the group did not get pregnant. This means the method is 93% effective with typical use.

How do birth control methods compare?

Phone with the natural cycles app and thermometer

Non-hormonal

Natural Cycles°

93%

Typical Use

Includes all unintended pregnancies, such as due to having unprotected sex or using withdrawal on a red day, as well as pregnancies that occur while the method is used as intended

98%

Perfect Use

Only includes pregnancies due to condoms breaking, or the app giving a wrong green day

Select other methods to compare

Typical Use

93%

Perfect Use

99%

A package of contraceptive pills

Contraceptive Pill

Typical Use

>99%

Perfect Use

>99%

Copper iud

Copper IUD

Typical Use

87%

Perfect Use

99%

illustration of a male condom

Condom

Typical Use

>99%

Perfect Use

>99%

hormonal iud illustration

Hormonal IUD

Typical Use

93%

Perfect Use

>99%

Illustration of NuvaRing

NuvaRing

Typical Use

80%

Perfect Use

96%

hand with crossed fingers

Pull Out Method

A package of contraceptive pills

Hormonal

Contraceptive Pill

93%

Typical Use

Includes pregnancies due to a woman forgetting to take the pill, or taking it at the wrong time.

99%

Perfect Use

Only includes pregnancies while using the pill exactly as specified by the manufacturer.

How does NC° Birth Control calculate its effectiveness?

As a regulated medical device, we follow rigorous processes to protect our users and we are constantly monitoring our Pearl Index. Our FDA clearance is based on the study of more than 15,000 women. The study looked at all possible reasons women become pregnant, including condoms failing and the app giving an incorrect green day.

NC° Birth Control Pearl Index

Out of 100 women over 1 year of use

7on average got pregnant in total

5from unprotected sex on red days

2despite using a condom or abstaining on red days

0.7from the app giving a wrong green day

Some common questions we get asked about effectiveness

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