Contraception and Birth Control

Contraception allows for the prevention of pregnancy and for planning the timing of pregnancy. Some methods can also protect against infections. Modern methods of contraception include oral contraceptives (such as birth control pills), contraceptive vaginal rings, condoms, intrauterine devices (also called IUDs), injectable and implantable products, and sterilization.

About Contraception and Birth Control

Contraception is the prevention of pregnancy. Contraception, or birth control, also allows couples to plan the timing of pregnancy. Some methods can also protect against infections. Choosing a particular method of birth control depends on many factors, including a woman’s overall health, age, frequency of sexual activity, number of sexual partners, desire to have children in the future, and family medical history. Individuals should work with their health care provider to choose a method that is best for them. It is also important to discuss birth control methods with one’s sexual partner.

General methods of contraception include:

  • Barrier—physically interferes with conception by keeping the egg and sperm apart
  • Hormonal—regulates ovulation by changing the balance of hormones related to development and release of the egg; changes cervical mucus to impair sperm function or transport
  • IUDs—small devices inserted into the uterus that change the conditions in the cervix and uterus to prevent pregnancy as well as inhibiting the transit of sperm from the cervix to the fallopian tubes.
  • Sterilization—surgical procedures that make a woman permanently unable to get pregnant and a man unable to get a woman pregnant

Some forms of birth control combine methods, such as IUDs that also release hormones.

Some types of birth control may carry serious risks for some individuals. For specific information about birth control, individuals should talk to their health care providers.

What are the different types of contraception?

There are many different types of contraception, but not all types are appropriate for all situations. The most appropriate method of birth control depends on an individual's overall health, age, frequency of sexual activity, number of sexual partners, desire to have children in the future, and family history of certain diseases.

Intrauterine Methods

An intrauterine device (IUD), also known as an intrauterine system (IUS), is a small, T-shaped device that is inserted into the uterus to prevent pregnancy. A health care provider inserts the device. An IUD can remain in place and function effectively for many years at a time. After the recommended length of time, or when the woman no longer needs or desires contraception, a health care provider removes or replaces the device.

  • A hormonal IUD or IUS releases a progestin hormone (levonorgestrel) into the uterus.3 The released hormone causes thickening of the cervical mucus, inhibits sperm from reaching or fertilizing the egg, thins the uterine lining, and may prevent the ovaries from releasing eggs. The failure rate of a hormonal IUS is less than 1%; however, a small percentage of women may experience expulsion of the device and have to have it reinserted.3 Some research also suggests that these IUDs maintain their effectiveness up to a year beyond their recommended use period.4 This method may also be used to treat heavy menstrual bleeding because the hormone often reduces or eliminates uterine bleeding.
  • copper IUD prevents sperm from reaching and fertilizing the egg, and it may prevent the egg from attaching in the womb.3 If fertilization of the egg does occur, the physical presence of the device prevents the fertilized egg from implanting into the lining of the uterus. The failure and expulsion/reinsertion rates of a copper IUD is similar to those of a hormonal IUD.3 Copper IUDs may remain in the body for 10 years.3 A copper IUD is not recommended for women who may be pregnant, have pelvic infections, or had uterine perforations during previous IUD insertions. It also is not recommended for women who have cervical cancer or cancer of the uterus, unexplained vaginal bleeding, or pelvic tuberculosis. Currently, ParaGard® is the only FDA-approved copper IUD.


Implants are implantable rods. Each rod is matchstick-sized, flexible, and plastic. The method has a failure rate of less than 1%.3 A physician surgically inserts the rod under the skin of the woman's upper arm.

The rod releases a progestin and can remain implanted for up to 5 years. Currently, Implanon® and Nexplanon®, which release etonogestrel, are the only implantable rods available in the United States. A two-rod method, Jadelle®, which releases levonorgestrel, is FDA approved but not currently distributed in America. A new levonorgestrel-releasing, two-rod method, Sino-implant (II)®, is in clinical development.

Short-Acting Hormonal Methods

Hormonal methods of birth control use hormones to regulate or stop ovulation and prevent pregnancy. Ovulation is the biological process in which the ovary releases an egg, making it available for fertilization. Hormones can be introduced into the body through various methods, including pills, injections, skin patches, transdermal gels, vaginal rings, intrauterine systems, and implantable rods. Depending on the types of hormones that are used, these methods can prevent ovulation; thicken cervical mucus, which helps block sperm from reaching the egg; or thin the lining of the uterus. Health care providers prescribe and monitor hormonal contraceptives.

Short-acting hormonal methods (e.g., injectables, pills, patches, rings) are highly effective if used perfectly, but in typical use, they have a range of failure rates.

  • Injectable birth control. This method involves injection of a progestin, Depo-Provera® (depot medroxyprogesterone acetate [DMPA]), given in the arm or buttocks once every 3 months.5 This method of birth control can cause a temporary loss of bone density, particularly in adolescents. However, this bone loss is generally regained after discontinuing use of DMPA. Most patients using injectable birth control should eat a diet rich in calcium and vitamin D or take vitamin supplements while using this medication. A new self-injectable formulation of DMPA, Sayana® Press, is approved in the United Kingdom and is expected to be approved more widely in the near future. This subcutaneous injectable product has a lower amount of hormone and may be more acceptable for some users.
  • Progestin-only pills (POPs). A woman takes one pill daily, preferably at the same time each day. POPs may interfere with ovulation or with sperm function. POPs thicken cervical mucus, making it difficult for sperm to swim into the uterus or to enter the fallopian tube. POPs alter the normal cyclical changes in the uterine lining and may result in unscheduled or breakthrough bleeding. These hormones do not appear to be associated with an increased risk of blood clots.

Combined Hormonal Methods

Combined hormonal methods contain a synthetic estrogen (ethinyl estradiol) and one of the many progestins approved in the United States. All of the products work by inhibiting ovulation and thickening cervical mucus. The combined estrogen/progestin drugs can be delivered by pills, a patch, or a vaginal ring. The combined hormonal methods have some medical risks, such as blood clots, that are associated with the synthetic estrogen in the product. These risks have not been observed with progestin-only hormonal methods such as injectable birth control, POPs, or hormonal LARCs. Your health care provider can discuss your risk factors and help you select the most appropriate contraceptive method for you.

  • Combined oral contraceptives (COCs, "the pill"). COCs contain a synthetic estrogen and a progestin, which functions to inhibit ovulation. A woman takes one pill daily, preferably at the same time each day. Many types of oral contraceptives are available, and a health care provider helps to determine which type best meets a woman's needs.
  • Contraceptive patch. This is a thin, plastic patch that sticks to the skin and releases hormones through the skin into the bloodstream. The patch is placed on the lower abdomen, buttocks, outer arm, or upper body. A new patch is applied once a week for 3 weeks, and no patch is used on the fourth week to enable menstruation.3 Currently, Ortho Evra® is the only patch that is FDA approved.
  • Vaginal ring. The ring is thin, flexible, and approximately 2 inches in diameter. It delivers a combination of ethinyl estradiol and a progestin. The ring is inserted into the vagina, where it continually releases hormones for 3 weeks. The woman removes it for the fourth week and reinserts a new ring 7 days later. Risks for this method of contraception are similar to those for the combined oral contraceptive pills. A vaginal ring may not be recommended for women with certain health conditions, including high blood pressure, heart disease, or certain types of cancer.6 Currently, the NuvaRing® is the only FDA-approved vaginal ring. A new contraceptive vaginal ring that can be used for 13 cycles is under clinical development.

Designed to prevent sperm from entering the uterus, barrier methods are removable and may be an option for women who cannot use hormonal methods of contraception. Failure rates for barrier methods differ depending on the method.7

Types of barrier methods that do not require a health care provider visit include the following:

  • Male condoms. This condom is a thin sheath that covers the penis to collect sperm and prevent it from entering the woman's body. Male condoms are generally made of latex or polyurethane, but a natural alternative is lambskin (made from the intestinal membrane of lambs). Latex or polyurethane condoms reduce the risk of spreading sexually transmitted diseases (STDs). Lambskin condoms do not prevent STDs. Male condoms are disposed of after a single use.
  • Female condoms. These are thin, flexible plastic pouches. A portion of the condom is inserted into a woman's vagina before intercourse to prevent sperm from entering the uterus. The female condom also reduces the risk of STDs. Female condoms are disposed of after a single use. 
  • Contraceptive sponges. These are soft, disposable, spermicide-filled foam sponges. One is inserted into the vagina before intercourse.8 The sponge helps block sperm from entering the uterus, and the spermicide also kills the sperm cells. The sponge should be left in place for at least 6 hours after intercourse and then removed within 30 hours after intercourse. 
  • Spermicides. A spermicide can kill sperm cells. A spermicide can be used alone or in combination with a diaphragm or cervical cap. The most common spermicidal agent is a chemical called nonoxynol-9 (N-9). It is available in several concentrations and forms, including foam, jelly, cream, suppository, and film. A spermicide should be inserted into the vagina close to the uterus no more than 30 minutes prior to intercourse and left in place 6 to 8 hours after intercourse to prevent pregnancy. Spermicides do not prevent the transmission of STDs and may cause allergic reactions or vaginitis (pronounced vaj-uh-NAHY-tis).9

Methods that require a health care provider visit include the following:

  • Diaphragms. Each diaphragm is a shallow, flexible cup made of latex or soft rubber that is inserted into the vagina before intercourse, blocking sperm from entering the uterus. Spermicidal cream or jelly should be used with a diaphragm. The diaphragm should remain in place for 6 to 8 hours after intercourse to prevent pregnancy, but it should be removed within 24 hours. Traditional latex diaphragms must be the correct size to work properly, and a health care provider can determine the proper fit.

    A diaphragm should be replaced after 1 or 2 years. Women also need to be measured for a new diaphragm after giving birth, having pelvic surgery, or gaining or losing more than 15 pounds.10 Newer diaphragms, such as Caya®, are designed to fit most women and do not require fitting by a health care provider.
  • Cervical caps. These are similar to diaphragms but are smaller and more rigid. The cervical cap is a thin silicone cup that is inserted into the vagina before intercourse to block sperm from entering the uterus. As with a diaphragm, the cervical cap should be used with spermicidal cream or jelly. The cap must remain in place for 6 to 8 hours after intercourse to prevent pregnancy, but it should be removed within 48 hours. Cervical caps come in different sizes, and a health care provider determines the proper fit.3 With proper care, a cervical cap can be used for 2 years before replacement.2 Currently, FemCap is the only cervical cap approved by the FDA. 

Emergency contraception can be used after unprotected intercourse or if a condom breaks.

  • Copper IUD. The copper IUD is the most effective method of emergency contraception. The device can be inserted within 120 hours of unprotected intercourse. The method is nearly 100% effective at preventing pregnancy and has the added benefit of providing a highly effective method of contraception for as long as the device remains in place. There are very few contraindications to use of the copper IUD, and there are no issues related to weight or obesity associated with the effectiveness of the method.
  • Emergency contraceptive pills (ECPs) are hormonal pills, taken either as a single dose or two doses 12 hours apart, that are intended for use in the event of unprotected intercourse. If taken prior to ovulation, the pills can delay or inhibit ovulation for at least 5 days to allow the sperm to become inactive. They also cause thickening of cervical mucus and may interfere with sperm function. ECPs should be taken as soon as possible after semen exposure and should not be used as a regular contraceptive method. Pregnancy can occur if the pills are taken after ovulation or if the woman has unprotected sex in the same cycle.

Sterilization is a permanent form of birth control that either prevents a woman from getting pregnant or prevents a man from releasing sperm. A health care provider must perform the sterilization procedure, which usually involves surgery. These procedures usually are not reversible.

  • A sterilization implant is a nonsurgical method for permanently blocking the fallopian (pronounced fuh-LOH-pee-uhn) tubes.11 A health care provider threads a thin tube through the vagina and into the uterus to place a soft, flexible insert into each fallopian tube. No incisions are necessary. During the next 3 months, scar tissue forms around the inserts and blocks the fallopian tubes so that sperm cannot reach an egg. After 3 months, a health care provider conducts tests to ensure that scar tissue has fully blocked the fallopian tubes. A backup method of contraception is used until the tests show that the tubes are fully blocked.
  • Tubal ligation (pronounced TOO-buhl lahy-GEY-shuhn) is a surgical procedure in which a doctor cuts, ties, or seals the fallopian tubes. This procedure blocks the path between the ovaries and the uterus. The sperm cannot reach the egg to fertilize it, and the egg cannot reach the uterus.12
  • Vasectomy (va-SEK-tuh-mee) is a surgical procedure that cuts, closes, or blocks the vas deferens (pronounced vas DEF-uh-renz). This procedure blocks the path between the testes and the urethra (yoo-REE-thruh).13 The sperm cannot leave the testes and cannot reach the egg. It can take as long as 3 months for the procedure to be fully effective. A backup method of contraception is used until tests confirm that there is no sperm in the semen.


  1. Department of Health and Human Services, Office on Women's Health. (2012). Birth control methods fact sheet. Retrieved September 8, 2016, from (PDF 136 KB)
  2. Planned Parenthood Federation of America, Inc. (2014). Birth control. Retrieved February 23, 2016, from external link
  3. U.S. Food and Drug Administration. (2015). Birth control: Medicines to help you. Retrieved February 17, 2016, from
  4. Williams, D. D. (2015). IUD, implant contraception effective beyond FDA-approved use. Retrieved June 20, 2016, from
  5. National Center for Biotechnology Information. (2010). Medroxyprogesterone injection. Retrieved February 23, 2016, from
  6. Centers for Disease Control and Prevention. (2013). U.S. Selected Practice Recommendations for Contraceptive Use, 2013: Adapted from the World Health Organization Selected Practice Recommendations for Contraceptive Use, 2nd Edition. Morbidity and Mortality Weekly Report, 62(RR05), 1–46. Retrieved September 12, 2016, from
  7. Trussell, J. (2011). Contraceptive failure in the United States. Contraception, 83(5), 397–404. Retrieved September 12, 2016, from
  8. U.S. Food and Drug Administration. (2023). Birth Control. Retrieved from
  9. American College of Obstetricians and Gynecologists. (2014). Barrier methods of contraception. Retrieved February 23, 2016, from external link (PDF 86 KB)
  10. Allen, R. E. (2004). Diaphragm fitting. American Family Physician, 69(1), 97–100.
  11. Conceptus. (2012). What is Essure? Retrieved February 23, 2016, from external link
  12. National Library of Medicine, MedlinePlus. (2013). Tubal ligation. Retrieved February 23, 2016, from
  13. National Library of Medicine, MedlinePlus. (2016). Vasectomy. Retrieved February 23, 2016, from

How effective is contraception?

Different methods of contraception have different rates of effectiveness in preventing pregnancy.

Contraception is most effective when used correctly and consistently. The failure rate increases if a method of contraception is used incorrectly or inconsistently.

Only male and female condoms are effective at reducing the spread of STDs.

For details about the effectiveness of specific methods of contraception, as well as potential side effects and risks, visit the website of the U.S. Department of Health and Human Services (HHS) Office on Women's Health.1


  1. Department of Health and Human Services, Office on Women's Health. (2012). Birth control methods fact sheet. Retrieved February 23, 2016, from (PDF 136 KB)

Can contraception reduce the risk of getting an infection?

Only condoms have been proven to reduce the risk of getting some STDs.

According to the HHS Office on Women's Health, the male latex condom is the best method for protecting against STDs, including HIV/AIDS.1 Polyurethane condoms are an effective alternative if either partner has a latex allergy. Natural/lambskin condoms do not prevent the spread of STDs because of the presence of tiny pores (holes) that may allow viruses such as HIV, hepatitis B, and herpes to spread.

The female condom has properties similar to the male condom, but researchers have not studied its effectiveness in reducing the spread of STDs as much as they have studied the male condom.

The most common STD is the human papilloma (pronounced pap-uh-LOH-muh) virus, or HPV. No method of contraception can fully prevent the transmission of HPV, because it can infect areas not covered by a condom. However, using a condom with every sex act can lower the risk of transmission.2

If you have questions about birth control and STDs, talk to your health care provider.

If you think you may have an STD, you should see your health care provider. NICHD provides additional information on the symptoms and treatment of STDs.


  1. Department of Health and Human Services, Office on Women's Health. (2012). Birth control methods fact sheet. Retrieved February 23, 2016, from (PDF 136 KB)
  2. U.S. Centers for Disease Control and Prevention. (n.d.). Condoms and STDs: Fact sheet for public health personnel. Retrieved February 23, 2016, from (PDF 1.6 MB) 

NICHD Contraception and Birth Control Research Goals

Controlling one's own reproduction involves not only the desire to have children, but also the ability to have them at a time and in a manner that best promotes the future health of the child, the family, and the community. NICHD research on contraception and birth control addresses a range of goals, including using advances in genetics to identify novel contraceptive leads, understanding their effectiveness and factors that influence effectiveness, and identifying new strategies for improving contraception use.

Some specific NICHD research goals related to contraception include (but are not limited to) the following:

  • Discovering associations of gene expression related to male fertility
  • Exploring gene function at the cellular level as a way to control fertility
  • Studying the effects of contraceptive molecules at the organism level using knockouts and transgenesis
  • Developing targeted nonhormonal contraceptive methods with minimal side effects
  • Identifying specific hormonal agents, targeting their delivery, and supporting research to formulate methods of contraception delivery
  • Designing new nonhormonal contraceptive approaches that capitalize on the biology of the testes and epididymis
  • Increasing knowledge about the factors that control spermatogenesis to design specific compounds for male contraception
  • Analyzing long-term health effects, including effects on the prostate and on bone mass, of new agents for male contraception
  • Studying couples regarding their perspectives on gender roles, sexual access and function, fertility management, and parenting responsibilities
  • Examining males’ influence on females’ access to and use of reproductive services
  • Studying the effects of larger cultural factors on use of contraception and perceptions of self-fertility management
  • Examining the effects of contraceptive experiences on individual risk-taking, partner relationships, risks for STDs, and pregnancy prevention across the lifespan
  • Researching the delivery of family planning services
  • Studying the sustained use of contraception and the reasons for discontinuation, inconsistent use, and method switching

Contraception and Birth Control Research Activities and Advances

NICHD relies on several organizational units to study different aspects of contraception, from the biological mechanisms of different methods to the relevant decisions and behaviors of individuals and couples. The information below describes a few of these activities.

NICHD has long been a source of funding for and expertise on contraception research. Extramurally, this expertise and support is led by what is now the Contraception Research Branch (CRB), although it has had slightly different names over the years. For some time, the CRB has focused on supporting and conducting research in contraceptive discovery and development, including dual-use methods that prevent both pregnancy and sexually transmitted diseases (STDs). The Branch is the largest source of support for research on contraceptive development within the federal government. It has responsibility for discovery, development, and evaluation of contraceptive agents.

The CRB uses a combination of grants and contracts to support and/or conduct activities including (but not limited to):

  • Phase I, II, III, or IV clinical trials to evaluate the safety and efficacy of new contraceptive methods for women and men
  • Research to develop methods for male contraception, including hormonal and nonhormonal control of sperm production and/or sperm function
  • Basic and translational contraceptive research and development that may lead to new hormonal or nonhormonal methods for inhibiting ovulation or fertilization
  • Experimental studies in animals to determine the safety and efficacy of novel potential contraceptive agents
  • Research to define optimal formulations and dosages of contraceptive agents, spermicidal microbicides, and therapies (in animals and humans)
  • Projects, as appropriate, on health effects related to contraceptive use and its relationship with other health issues, such as cancer
  • Expertise about contraception and contraceptives that contributes to discussions, reports, and evidence-based recommendations, including those of the Cochrane Collaboration and the World Health Organization

The CRB addresses many of these research topics through cooperative agreements with research centers and research networks. These collaborative approaches are described in the Other Activities and Advances section.

Other extramural Branches—such as the Population Dynamics Branch (PDB), the Fertility and Infertility (FI) Branch, and the Gynecologic Health and Disease Branch (GHDB)—study different aspects of contraception, but not development or testing of contraceptive agents. For example:

  • PDB funds research on demographic, social, and behavioral aspects of sexual behaviors and their relationship to contraceptive use and non-use in both domestic and international populations. These efforts include studies of the determinants and consequences of contraceptive use in men and women, and basic and interventional research on the sexual transmission of HIV and other STDs. A particular focus of Branch-funded research is the interrelationships among pregnancy, pregnancy prevention, and prevention of STDs.
  • The FI Branch supports research to alleviate human infertility, uncover new possible pathways to control fertility, and expand fundamental knowledge of processes that underlie human reproduction. Within this context, the FI Branch studies molecular and basic mechanisms of reproductive processes as a way to regulate fertility.
  • GHDB supports basic, translational, and clinical research programs related to gynecologic health throughout the reproductive lifespan, starting at puberty and extending through the early menopause. Branch projects include studies to understand and treat gynecological problems, such as endometriosis, uterine fibroids, and heavy menstrual bleeding, including using contraceptive agents in these treatments.

In 2014 to 2015, NICHD convened an expert panel, comprising experts in basic, clinical, and behavioral research and representatives of industry and non-governmental organizations. The panel was charged with assessing the past accomplishments and impact of NICHD's contraceptive research initiatives, the current status of contraception research at and funded by NICHD, and suggestions for future activities and directions in contraception research. Activities of the CRB, PDB, and FI Branch were the focus of the panel's efforts.

The panel presented its findings to the NICHD advisory council in January 2015, and NICHD is in the process of implementing some of the panel's findings and ideas. You can read more about the panel and its findings at Assessment of the Contraceptive Research Activities of the NICHD: Executive Summary (PDF - 138 KB).

The Cell Regulation and Development Affinity Group, part of the Institute's Division of Intramural Research (DIR), investigates the molecular basis of peptide hormone control of gonadal function and is working on research to support the development of a male contraceptive.

As NICHD continues shifting the priorities of its various components, its commitment to supporting and conducting contraception research—including development of new contractive compounds—remains.

  • In 1996, NICHD established the Contraceptive Clinical Trials Network (CCTN) to conduct clinical trials of new contraceptive drugs and devices. Sites within the CCTN, funded through the CRB, are chosen based on their capacity to conduct Phase I, II, and III trials for contraceptive drugs and devices. CCTN research includes studies of:
    • The ability of progestin- and testosterone-based topical gels to inhibit sperm production to provide hormonal contraception for men
    • A progesterone receptor modulator, CDB-2914, as an emergency oral contraceptive for women when taken within 72 hours of unprotected intercourse
    • The effectiveness of a new female condom to prevent both pregnancy and STDs
    • Progestin-based compounds that can prevent pregnancy without increasing the risk of blood clots and other venous thromboembolism-type conditions, especially in obese women
    • A progestin- and estradiol-releasing vaginal ring that would be an effective contraceptive without increasing the risk of blood clots and other venous thromboembolism-type conditions, especially in obese women
  • Congress mandated the creation of the Contraceptive Development Research Center Program (CDRCP) in 1993 to fund research centers to develop new contraceptive products. The program is supported through the Institute's CRB and currently includes three centers. The CDRCP also serves as a national resource for supporting the career development of young scientists who want to pursue research in fertility regulation. CDRCP research topics include:
    • Developing a male contraceptive that inhibits an enzyme needed to produce sperm
    • Developing a vaginal ring that acts as a contraceptive and also promotes brain health
    • Understanding how egg cells develop and mature and how they are released to be fertilized
    • Developing new delivery methods for contraceptive agents
    • Developing dual-use compounds that protect against sexually transmitted infections and pregnancy
    • Conducting translational research to identify or optimize male contraceptive products
    • Developing nonhormonal contraception methods that inhibit ovulation
  • Funded through the CRB, the Preclinical Contraceptive Development Program (PCDP) conducts a wide range of research with the goal of developing useful contraceptive products for men. Research focuses for the program include studies on:
    • How mechanisms regulating sperm maturation might be targeted by novel male contraceptives
    • How sperm development could be inhibited using l targets, such as by disrupting the tight junctions between Sertoli cells and germ cells
    • Testing of injectable form of acyline, a male hormonal contraceptive, to assess safety and ability to suppress spermatogenesis
    • Development of an oral contraceptive for men, H2-gamendazole
top of pageBACK TO TOP