A guide to birth control
How well each method works and how to choose
The figures below are widely cited typical-use numbers — the share of people who did not get pregnant over a year of using that method. How closely you follow the instructions changes the result.
IUD
A small device placed inside the uterus. Comes in copper and hormonal versions.
Over 99%
Lasts 3 to 10 years once fitted. Insertion and removal are done by a clinician.
Implant & injection
A small rod placed under the skin of the upper arm, or a hormone shot repeated on a schedule.
Implant over 99% · shot about 94%
Nothing to remember daily. The shot only keeps working if you go back on schedule.
The pill
A hormone tablet taken at the same time every day.
About 91%
Missing days drops the effectiveness sharply. A daily reminder helps — you can turn one on in LunaCat.
Condoms
A barrier worn during sex, used every time.
About 85%
Close to the only method that also protects against sexually transmitted infections.
Fertility awareness
Timing sex to avoid the days around ovulation.
About 77%
A small shift in your cycle throws the prediction off. The fertile window in this app is not birth control either.
Emergency contraception
For when you had sex without contraception or something failed. The sooner the better — within 72 to 120 hours at the latest. In the US, levonorgestrel pills (such as Plan B) are sold over the counter with no age limit; ulipristal (ella) and the copper IUD need a prescription and work later in the window. It is not a substitute for a regular method.
It is a backup for an unexpected situation, not a replacement for a regular method.
Questions to ask yourself
Can you keep up with something daily? If not, an implant or IUD — set once and left alone — tends to suit better.
Do you also need STI protection? Nothing but condoms provides it, so many people use them alongside another method.
When might you want to get pregnant? How quickly fertility returns after stopping differs by method.
Do you have a health condition or take other medication? Hormonal methods are not right for everyone, so check with a doctor.
A fertile window is not birth control
The fertile window and ovulation dates in this app are estimates from your past cycles. Stress, sleep, or a weight change alone can move ovulation by days. If your goal is preventing pregnancy, use an actual method.
Also protects against STIs
Does not protect against STIs
Worth knowing
These figures are typical use, not perfect use. Used exactly as directed each method does better — these numbers reflect how people actually use them.
Only condoms protect against STIs. If you need that protection, use them alongside whatever else you are on.
The right method is different for everyone. Your health, whether you smoke, and other medication can all rule options in or out, so it is worth talking it through at a clinic or with your doctor.