Birth Control

What is birth control?

Birth control, also known as contraception, refers to methods or devices used to prevent pregnancy. It allows you to decide if and when you want to have children. There are many methods of birth control, each differing in how they work, their effectiveness, and side effects. Some of the most common forms include hormonal methods, barrier methods, intrauterine devices (IUDs), sterilization, natural methods, and emergency contraceptive pills. The type you choose depends on your health, your desire to have children now or in the future, and whether you need protection against sexually transmitted infections (STIs).

Each method has advantages and disadvantages, and effectiveness can vary. It is important to choose a method that fits your health, lifestyle, and future family plans.

How does birth control work?

Birth control methods work in different ways to prevent pregnancy. Here is how the main types of birth control work:

Hormonal Methods

  • Combination oral contraceptives (the pill): contain estrogen and progestin to prevent ovulation, thicken cervical mucus, and thin the uterine lining.

  • Progestin-only pills (mini-pill): contain only progestin; prevent ovulation, thicken mucus, and thin the lining; must be taken at the same time daily.

  • Birth control patch: delivers hormones through the skin to prevent ovulation.

  • Birth control injection: progestin shot every three months that prevents ovulation and alters cervical mucus and uterine lining.

  • Vaginal ring: flexible ring placed in the vagina that releases hormones locally to prevent pregnancy.

  • Contraceptive implants: small rod under the skin releasing progestin for up to five years; nearly 100% effective.

Barrier Methods

  • Condoms: physical barrier preventing sperm from entering the vagina; also protect against STIs.

  • Diaphragm and cervical cap: devices placed over the cervix, used with spermicide to block and kill sperm.

  • Spermicides: chemicals that damage or kill sperm, used alone or with other barrier methods.

Intrauterine Devices (IUDs)

  • Copper IUD: releases copper ions toxic to sperm; lasts up to 10 years.

  • Hormonal IUD: releases progestin to thicken cervical mucus, thin the lining, and sometimes prevent ovulation; lasts 3–7 years depending on type.

Sterilization

  • Tubal ligation: surgical cutting, tying, or sealing of the fallopian tubes to prevent eggs from reaching the uterus.

  • Vasectomy: surgical cutting or blocking of the vas deferens to prevent sperm from entering ejaculate.

Natural Methods

  • Fertility awareness: tracking ovulation signs and avoiding intercourse or using barriers on fertile days.

  • Withdrawal: removing the penis before ejaculation to lower the chance of sperm reaching the egg.

Emergency Contraception

  • Morning-after pill: high-dose hormones taken up to five days after unprotected sex; most effective within 72 hours.

  • Copper IUD: can be inserted within five days of unprotected sex to prevent fertilization and implantation.

What are the types of birth control?

Hormonal Contraceptives

  • Oral contraceptives (the pill): up to 99% effective when taken correctly; combination pills (estrogen + progestin) and progestin-only pills.

  • Contraceptive patch: up to 99% effective when used correctly; hormone-releasing patch worn weekly.

  • Contraceptive injection (Depo-Provera): >99% effective with perfect use; progestin shot every three months.

  • Vaginal ring (NuvaRing): up to 99% effective when used correctly; flexible hormone-releasing ring replaced monthly.

  • Implants (Nexplanon): >99% effective; progestin-releasing rod under the arm for up to five years.

Barrier Methods

  • Male condoms: 98% effective with perfect use, 87% typical use.

  • Female condoms: 95% effective perfect, 79% typical use.

  • Diaphragm: 94% effective perfect, 83% typical; used with spermicide.

  • Cervical cap: 86% effective if never given birth, 71% if given birth; used with spermicide.

  • Birth control sponge: 91% effective if never given birth, 80% if given birth.

  • Spermicides alone: 79% effective.

Intrauterine Devices (IUDs)

  • Copper IUD (ParaGard): >99% effective.

  • Hormonal IUDs (Mirena, Skyla, Kyleena, Liletta): >99% effective.

Permanent Methods

  • Tubal ligation: >99% effective.

  • Vasectomy: nearly 100% effective.

Natural Methods

  • Fertility awareness methods (FAMs): 77%–98% effective.

  • Withdrawal method: 78%–96% effective.

  • Lactational amenorrhea method (LAM): up to 98% effective for six months postpartum if exclusive breastfeeding and no menstruation.

Emergency Contraception

  • Morning-after pill (Plan B, Ella): 75%–89% effective within 3 days; ulipristal (Ella) by prescription; levonorgestrel OTC options.

  • Copper IUD: >99% effective if inserted within five days.

What are the side effects of birth control?

  • Oral contraceptives: nausea, headaches, breast tenderness, weight changes, mood changes, irregular bleeding, increased blood clot risk with estrogen.

  • Contraceptive patch: similar to the pill plus possible skin irritation.

  • Birth control shot: weight gain, bone density loss (long-term), irregular bleeding, mood changes.

  • Vaginal ring: irritation, discharge, plus pill-like side effects.

  • Implants: irregular bleeding, weight changes, mood swings, breast tenderness.

  • Hormonal IUDs: spotting, irregular bleeding, breast tenderness, mood changes.

  • Copper IUDs: heavier periods, cramping, spotting, insertion pain.

  • Sponge, diaphragm, cervical cap: irritation from spermicide, small risk of toxic shock syndrome with sponge.

Discuss any concerns or side effects with your healthcare provider.

Sources

  • Birth control methods. U.S. Department of Health and Human Services Office on Women’s Health. Accessed May 16, 2024.
  • Contraception. Centers for Disease Control and Prevention. Accessed May 16, 2024.
  • Birth Control. Planned Parenthood. Accessed May 16, 2024.
  • About Contraception and Birth Control. Eunice Kennedy Shriver National Institute of Child Health and Human Development. Accessed May 16, 2024.
  • Birth Control Methods. Office on Women’s Health. Accessed May 16, 2024.