Birth control methods fall into five broad categories: hormonal methods, long-acting reversible devices, barrier methods, behavioral methods, and permanent sterilization. The most effective options, like IUDs and implants, result in fewer than 1 pregnancy per 100 women per year, while the least effective, like spermicides used alone, allow 21 to 28 pregnancies per 100 women per year. Choosing between them comes down to how much effort you want to put in, whether you’re comfortable with hormones, and how important near-perfect effectiveness is to you.
Long-Acting Reversible Methods
IUDs and implants sit at the top of the effectiveness chart. They’re placed once by a healthcare provider and then work on their own for years, which eliminates the daily or per-encounter effort that leads to human error with other methods. Fewer than 1 in 100 women using these methods will become pregnant in a year.
There are two types of IUDs. Hormonal IUDs release a small amount of progestin directly into the uterus, which thins the uterine lining and thickens cervical mucus so sperm can’t easily reach an egg. Depending on the brand, they last 3 to 8 years. Many women notice lighter periods or lose their period entirely while using one, which is why hormonal IUDs are also prescribed for heavy menstrual bleeding and cramping. The copper IUD contains no hormones at all. Instead, copper creates an environment inside the uterus that’s toxic to sperm. It’s approved for up to 10 years, making it the longest-lasting reversible option available.
The contraceptive implant is a small rod placed under the skin of the upper arm. It releases progestin and prevents ovulation. Like IUDs, it has a failure rate of less than 1 in 100 women per year. All three of these methods are fully reversible: fertility typically returns quickly once the device is removed.
Hormonal Methods You Manage Yourself
Combined hormonal methods contain both estrogen and progestin. This group includes the combination pill, the skin patch, and the vaginal ring. All three prevent ovulation, thin the uterine lining, and thicken cervical mucus. With typical, real-world use, about 7 out of 100 women using any of these methods will become pregnant in a year. That gap between their near-perfect design and their real-world performance comes down to missed pills, late patch changes, or forgetting to swap a ring on time.
The progestin-only mini pill also has a typical failure rate of about 7 per 100 women per year. It works primarily by thickening cervical mucus and thinning the uterine lining, and it’s an option for people who can’t take estrogen (for example, those who get migraines with aura or are breastfeeding).
The contraceptive injection is given every few months by a provider. It uses progestin to suppress ovulation. Its typical-use failure rate is about 4 per 100 women per year, better than the pill because there’s less room for user error, though not quite as hands-off as an IUD or implant.
Health Risks of Hormonal Methods
The most talked-about risk with combined hormonal methods is blood clots. For women not using any hormonal contraception, blood clots occur at a rate of about 1 to 5 per 10,000 women per year. Combined methods raise that to roughly 3 to 15 per 10,000 women per year. For context, pregnancy itself carries a much higher clot risk: 5 to 20 per 10,000 woman-years, and the postpartum period jumps to 40 to 65 per 10,000. So while the risk is real, it’s small in absolute terms, and it’s lower than the risk from the pregnancy these methods prevent. The patch and vaginal ring carry a similar clot risk to the pill, with studies showing rates of about 11 to 12 per 10,000 women per year. Progestin-only methods (the mini pill, the injection, hormonal IUDs, and the implant) are not associated with this increased clot risk.
Benefits Beyond Pregnancy Prevention
Hormonal birth control is frequently prescribed for reasons that have nothing to do with preventing pregnancy. Combined methods can reduce acne, ease painful periods, lower the risk of ovarian cysts, and relieve symptoms of endometriosis. Some formulations reduce symptoms of premenstrual dysphoric disorder. Long-term use of combined pills is also associated with a reduced risk of ovarian and endometrial cancer. The hormonal IUD specifically helps with heavy menstrual bleeding, and the injection has been shown to reduce the frequency of seizures in women with seizure disorders and the number of crises in women with sickle cell disease.
Barrier Methods
Barrier methods physically block sperm from reaching the egg. They’re hormone-free and used only at the time of sex, which appeals to people who want to avoid daily or long-term commitments. The trade-off is lower effectiveness, because they depend entirely on correct use every single time.
The male (external) condom is the most widely used barrier method. Made from latex, polyurethane, or natural membrane, it has a typical-use failure rate of 13 per 100 women per year. Latex and polyurethane condoms also protect against sexually transmitted infections, including HIV. Natural membrane condoms do not. The female (internal) condom is a plastic pouch that lines the vagina, held in place by rings at each end. It can be inserted up to 8 hours before sex. Its typical-use failure rate is 21 per 100.
The diaphragm and cervical cap are silicone cups placed over the cervix before sex. Both are used with spermicide. The diaphragm has a typical failure rate of 17 per 100 women, while the cervical cap is somewhat less reliable at 22 to 23 per 100. The contraceptive sponge, which contains spermicide and is placed over the cervix, has a failure rate of 17 per 100 and works for up to 24 hours once inserted. It needs to stay in place for at least 6 hours after the last act of intercourse.
Spermicides used alone, available as foams, gels, creams, films, and suppositories, are among the least effective options at 21 to 28 pregnancies per 100 women per year. They need to be inserted close to the cervix 10 to 15 minutes before sex, remain effective for only about an hour, and must be reapplied for each act of intercourse. There’s also a newer non-hormonal vaginal gel that works by regulating vaginal pH to immobilize sperm. In clinical trials, it had a 7-cycle pregnancy rate of about 14%, putting it in a similar range to condoms. Combining a condom with spermicide or another barrier method improves protection over using either alone.
Behavioral Methods
Fertility awareness-based methods involve tracking your menstrual cycle to identify fertile days, then either abstaining from sex or using a barrier method during that window. These methods vary widely in effectiveness depending on the approach. The symptothermal method, which combines daily temperature readings with cervical mucus observations, has a correct-use pregnancy rate as low as 0.4 per 100 women and a typical-use rate of about 1.8 per 100. That’s remarkably effective when done consistently, though it requires daily commitment and careful record-keeping.
Calendar-based approaches are less precise. The Standard Days Method, which assumes fertility falls between days 8 and 19 of a regular cycle, has a correct-use failure rate of about 5 per 100 and a typical-use rate of 12 per 100. Software apps designed for contraception, which use algorithms to predict fertile windows, land at about 7 to 8 pregnancies per 100 women in typical use.
Withdrawal (pulling out before ejaculation) is one of the oldest contraceptive strategies. It’s free and always available, but it relies heavily on timing and self-control, and pre-ejaculate can contain sperm. Typical-use failure rates are generally estimated at around 20 per 100 women per year.
Permanent Sterilization
Sterilization is intended to be a permanent decision. Both tubal ligation (for women) and vasectomy (for men) are more than 99% effective. The procedures differ significantly in terms of what’s involved.
A vasectomy is done in a doctor’s office under local anesthesia. It blocks or cuts the tubes that carry sperm, and recovery is relatively quick. Tubal ligation requires abdominal surgery, typically performed under general anesthesia. While still considered minor surgery, it’s a more involved procedure with a longer recovery. In rare cases, tubal ligation can fail if the tubes heal back together, which carries a risk of ectopic pregnancy. Because vasectomy is simpler, faster, and less invasive, it’s often the recommended option for couples who are certain they don’t want future pregnancies.
Emergency Contraception
Emergency contraception is a backup option used after unprotected sex or contraceptive failure, not a routine method. There are two types of emergency contraceptive pills. One type, available over the counter, prevents about 7 out of 8 pregnancies that would have occurred. A prescription option is more effective when taken between 72 and 120 hours (3 to 5 days) after intercourse. Both types should ideally be taken as soon as possible, and both can be used within a 5-day window. Emergency contraceptive pills are less effective in women with a BMI over 30, though they remain safe to use.
The copper IUD is the most effective form of emergency contraception when inserted within 5 days of unprotected sex, and it then provides ongoing contraception for up to 10 years.
Comparing Effectiveness at a Glance
- Fewer than 1 pregnancy per 100 women/year: IUDs, implant, sterilization
- 4 per 100: Contraceptive injection
- 7 per 100: Pill, patch, ring, mini pill
- 7 to 8 per 100: Contraception apps
- 12 to 13 per 100: Condoms, calendar-based fertility tracking
- 17 per 100: Diaphragm, sponge
- 21 to 28 per 100: Female condom, cervical cap, spermicides
These numbers reflect typical use, meaning real-world conditions where people sometimes forget, misuse, or skip their method. With perfect use, nearly every method performs significantly better. The key insight is that methods requiring less day-to-day effort tend to have the smallest gap between perfect and typical effectiveness, because there’s less opportunity for human error.