The effectiveness of birth control methods is critically important for reducing the risk of unintended pregnancy. Effectiveness can be measured during “perfect use,” when the method is used correctly and consistently as directed, or during “typical use,” which is how effective the method is during actual use (including inconsistent and incorrect use).4
The best way to reduce the risk of unintended pregnancy among women who are sexually active is to use effective birth control correctly and consistently. Among reversible methods of birth control, intrauterine contraception and the contraceptive implant remain highly effective for years once correctly in place. The effectiveness of the contraceptive shot, pills, patch and ring, and barrier and fertility awareness-based methods, depends on correct and consistent use—so these methods have lower effectiveness with typical use.
For each method of birth control, effectiveness with typical use is provided below. We present this as the percent of women who experience an unintended pregnancy within the first year of typical use (also known as the failure rate).
- Copper T intrauterine device (IUD) —This IUD is a small device that is shaped in the form of a “T.” Your doctor places it inside the uterus to prevent pregnancy. It can stay in your uterus for up to 10 years. Typical use failure rate: 0.8%.
- Levonorgestrel intrauterine system (LNG IUD)—The LNG IUD is a small T-shaped device like the Copper T IUD. It is placed inside the uterus by a doctor. It releases a small amount of progestin each day to keep you from getting pregnant. The LNG IUD stays in your uterus for up to 5 years. Typical use failure rate: 0.2%.
- Implant—The implant is a single, thin rod that is inserted under the skin of a women’s upper arm. The rod contains a progestin that is released into the body over 3 years. Typical use failure rate: 0.05%.
- Injection or "shot"—Women get shots of the hormone progestin in the buttocks or arm every three months from their doctor. Typical use failure rate: 6%.
- Combined oral contraceptives—Also called “the pill,” combined oral contraceptives contain the hormones estrogen and progestin. It is prescribed by a doctor. A pill is taken at the same time each day. If you are older than 35 years and smoke, have a history of blood clots or breast cancer, your doctor may advise you not to take the pill. Typical use failure rate: 9%.
- Progestin only pill—Unlike the combined pill, the progestin-only pill (sometimes called the mini-pill) only has one hormone, progestin, instead of both estrogen and progestin. It is prescribed by a doctor. It is taken at the same time each day. It may be a good option for women who can’t take estrogen. Typical use failure rate: 9%.
- Patch—This skin patch is worn on the lower abdomen, buttocks, or upper body (but not on the breasts). This method is prescribed by a doctor. It releases hormones progestin and estrogen into the bloodstream. You put on a new patch once a week for three weeks. During the fourth week, you do not wear a patch, so you can have a menstrual period. Typical use failure rate: 9%, but may be higher in women who weigh more than 198 pounds.
- Hormonal vaginal contraceptive ring—The ring releases the hormones progestin and estrogen. You place the ring inside your vagina. You wear the ring for three weeks, take it out for the week you have your period, and then put in a new ring. Typical use failure rate: 9%.
- Emergency contraception—Emergency contraception is NOT a regular method of birth control. Emergency contraception can be used after no birth control was used during sex, or if the birth control method failed, such as if a condom broke.
- Women can have the Copper T IUD inserted within five days of unprotected sex.
- Women can take emergency contraceptive pills up to 5 days after unprotected sex, but the sooner the pills are taken, the better they will work. There are three different types of emergency contraceptive pills available in the United States. Some emergency contraceptive pills are available over the counter.
- Diaphragm or cervical cap—Each of these barrier methods are placed inside the vagina to cover the cervix to block sperm. The diaphragm is shaped like a shallow cup. The cervical cap is a thimble-shaped cup. Before sexual intercourse, you insert them with spermicide to block or kill sperm. Visit your doctor for a proper fitting because diaphragms and cervical caps come in different sizes. Typical use failure rate: 12%.
- Male condom—Worn by the man, a male condom keeps sperm from getting into a woman’s body. Latex condoms, the most common type, help prevent pregnancy, and HIV and other STDs, as do the newer synthetic condoms. “Natural” or “lambskin” condoms also help prevent pregnancy, but may not provide protection against STDs, including HIV. Typical use failure rate: 18%.
Condoms can only be used once. You can buy condoms, KY jelly, or water-based lubricants at a drug store. Do not use oil-based lubricants such as massage oils, baby oil, lotions, or petroleum jelly with latex condoms. They will weaken the condom, causing it to tear or break.
- Female condom—Worn by the woman, the female condom helps keeps sperm from getting into her body. It is packaged with a lubricant and is available at drug stores. It can be inserted up to eight hours before sexual intercourse. Typical use failure rate: 21%, and also may help prevent STDs.
- Spermicides—These products work by killing sperm and come in several forms—foam, gel, cream, film, suppository, or tablet. They are placed in the vagina no more than one hour before intercourse. You leave them in place at least six to eight hours after intercourse. You can use a spermicide in addition to a male condom, diaphragm, or cervical cap. They can be purchased at drug stores. Typical use failure rate: 28%.
- Natural family planning or fertility awareness—Understanding your monthly fertility pattern can help you plan to get pregnant or avoid getting pregnant. Your fertility pattern is the number of days in the month when you are fertile (able to get pregnant), days when you are infertile, and days when fertility is unlikely, but possible. If you have a regular menstrual cycle, you have about nine or more fertile days each month. If you do not want to get pregnant, you do not have sex on the days you are fertile, or you use a barrier method of birth control on those days. Failure rates vary across these methods. Overall, typical use failure rate: 24%.
Contraceptive sterilization is a permanent, safe, and highly effective approach for birth control. These methods are meant for people who are sure that they do not desire a pregnancy in the future.
The following methods have a typical use failure rate of less than 1%.
- Female Sterilization—Tubal ligation or “tying tubes”— A woman can have her fallopian tubes tied (or closed) so that sperm and eggs cannot meet for fertilization. The procedure can be done in a hospital or in an outpatient surgical center. You can go home the same day of the surgery and resume your normal activities within a few days. This method is effective immediately.
- Transcervical Sterilization— A thin tube is used to thread a tiny device into each fallopian tube. It irritates the fallopian tubes and causes scar tissue to grow and permanently plug the tubes. It can take about three months for the scar tissue to grow, so use another form of birth control during this time. Return to your doctor for a test to see if scar tissue has fully blocked your fallopian tubes.
- Male Sterilization–Vasectomy—This operation is done to keep a man’s sperm from going to his penis, so his ejaculate never has any sperm in it that can fertilize an egg. The procedure is done at an outpatient surgical center. The man can go home the same day. Recovery time is less than one week. After the operation, a man visits his doctor for tests to count his sperm and to make sure the sperm count has dropped to zero; this takes about 12 weeks. Another form of birth control should be used until the man’s sperm count has dropped to zero.Although most women and men who undergo contraceptive sterilization do not regret having had the procedure, the permanence of the method is an important consideration, as regret has been documented in studies. For example, the U.S. Collaborative Review of Sterilization (CREST) study found that women who were younger at the time of the procedure were more likely to experience regret. Read the following to learn more:
An additional issue addressed by the CREST study was the question of whether women who underwent contraceptive sterilization developed a “post-tubal ligation syndrome” of menstrual abnormalities, something that had been debated for years. Results indicated that menstrual abnormalities were no more common among women who had undergone tubal sterilization than among women who had not. (The risk of menstrual abnormalities after tubal sterilization. [PDF - 98KB] N Engl J Med. 2000;343:1681–1687).When considering a vasectomy, it’s important to understand that failures can occur. CDC research has estimated there is a probability of 11 failures per 1,000 procedures over 2 years; half of the failures occurred in the first three months after the vasectomy, and no failures occurred after 72 weeks.1 CDC research also examined regret among women whose partner underwent a vasectomy.2 In interviews with female partners of men who received vasectomies, CDC found that while most women did not regret their husband's vasectomies, the probability of regret over 5 years was about 6%. This is why it is important to know facts about this and other permanent forms of birth control before making a decision.
- Poststerilization regret: findings from the United States Collaborative Review of Sterilization. Obstet Gynecol. 1999;93:889–895.
- Regret following female sterilization at a young age: a systematic review.Contraception. 2006;73(2):205–210.
- Abstracts of publications from the Collaborative Review of Sterilization (CREST) study. [PDF - 153]