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Morning After Pill

Emergency Contraception, Post Coital Pill


About the morning after pill

The morning after pill is a form of emergency contraception. Unlike other forms of contraception, it is used after sexual intercourse to reduce the risk of pregnancy.

Also known as emergency contraceptive pills, the morning after pill is a contraceptive option for women who have had unprotected intercourse. Intercourse may be defined as unprotected when:

  • No contraception was used.
  • The contraceptive method failed (e.g., condom breaking, diaphragm slipping out of place).
  • The contraceptive method was used incorrectly (e.g., birth control pills were not taken properly).

Emergency contraceptive pills contain the same hormones as birth control pills. Some versions contain a combination of the hormones estrogen and progestin (a synthetic form of progesterone). Others only contain progestin. These hormones prevent pregnancy by:

  • Preventing ovulation (the release of an egg by an ovary)
  • Preventing fertilization (the penetration of an egg by sperm)
  • Preventing implantation (the embedding of a fertilized egg into the lining of the uterus)

Although emergency contraceptive pills contain the same hormones as birth control pills, the hormones are present in much higher doses. As a result, morning after pills should never be used on a regular basis.

According to the National Women’s Health Information Center (NWHIC), emergency contraceptive pills containing a combination of estrogen and progestin are approximately 75 percent effective in preventing pregnancy. Pills that only contain progestin are approximately 89 percent effective. The morning after pill is effective because human conception rarely occurs immediately after sexual intercourse. Instead it takes place after ovulation, which may occur as long as several days later. After intercourse, sperm may continue to travel in the fallopian tube until an egg is released. During this time the morning after pill can be taken, resulting in prevention of the pregnancy.

Emergency contraceptive pills, however, do not work if the woman is already pregnant. Unlike the “abortion pill” which causes the uterus to expel the egg and end the pregnancy, the morning after pill prevents pregnancy. It is important to remember that these drugs do not protect against the human immunodeficiency virus (HIV) or other sexually transmitted diseases (STDs).

The term “morning after pill” is misleading because emergency contraceptive pills are never taken in a single dose. Instead, two doses are required. The first dose should be taken as soon as possible after the act of unprotected intercourse, and no more than 72 hours (three days) after the act of unprotected intercourse. The second dose should be taken 12 hours after the initial dose. The number of pills taken in each dose depends on the brand. Women should take the pills exactly as instructed by their physician or healthcare professional.

After taking the first dose, women must use another form of contraception any time they have vaginal intercourse until their next menstrual period. A woman who regularly uses barrier methods of contraception, such as condoms, diaphragms and spermicides may use them immediately after taking the pills. Women who regularly use hormonal methods of contraception, including birth control pills, contraceptive injections, the contraceptive patch and the contraceptive ring, should consult with their physician about when they may safely use these methods again. If menstruation does not begin within three weeks, or any other signs of pregnancy appear, the woman should immediately contact her obstetrician-gynecologist (ObGyn).

In cases where pregnancy occurs despite use of the morning after pill, recent research suggests that there are no adverse consequences for the mother or her developing fetus.

For women who wait longer than 72 hours, there is another form of emergency contraception available. A “T” shaped device known as a copper-bearing intrauterine device (IUD) can be inserted into the uterus by a health care professional up to seven days after an act of unprotected sex. Once inserted, the device prevents a fertilized egg from implanting itself in the wall of the uterus. The device can be removed by the physician after the woman’s next menstrual period, or it can be left in place for up to 10 years as a regular method of contraception. This type of emergency contraception is a good alternative for women who cannot safely take the hormones contained in emergency contraceptive pills.

The IUD is also more effective in preventing pregnancy. According to the NWHIC, the copper-bearing IUD is 99.9 percent effective in preventing pregnancy. The effectiveness of these methods, however, is greatly affected by timing. The earlier a woman receives emergency contraception after unprotected intercourse, the greater the chance for success.

The Food and Drug Administration approved the sale of the emergency contraceptive drug levonorgestrel (Plan B) without prescription for women aged 18 and older in August 2006. The pills will only be sold behind the counter at pharmacies and women will be required to show photo identification for proof of age to obtain them. It is important to note, however, that a woman should not take high doses of her own birth control pills to prevent a pregnancy. Although birth control pills can be used as emergency contraception, proper use requires instruction from a physician or healthcare professional.


Types and differences of morning after pills

The morning after pill contains the same hormones as birth control pills. In fact, the Food and Drug Administration (FDA) has approved some brands of birth control pills for use as emergency contraception. However, women should not take birth control pills for emergency contraception without consulting with a physician, preferably an obstetrician-gynecologist (ObGyn). Drugs being used for emergency contraception are taken differently than regular birth control pills, and should only be taken under the guidance of a physician.

Brands of pills manufactured for use only as emergency contraception include:

Generic nameBrand name


Plan B

Brands of birth control pills that may be used as emergency contraception include:

Generic nameBrand name

levonorgestrel and ethinyl estradiol

Alesse, Aviane, Levlen, Levlite, Levora, Nordette, Tri–Levlen, Triphasil, Trivora

norgestrel and ethinyl estradiol

Lo/Ovral, Low–Ogestrel, Ogestrel, Ovral



Although some brands of birth control pills have been approved for safe use as emergency contraception, women should not assume that taking a large amount of their own birth control pills will be effective in preventing pregnancy. The method in which different brands of pills are taken to prevent pregnancy differs. Women who are interested in using emergency contraceptive pills are encouraged to become informed about the different options available as well as discuss with their ObGyn to find out which type will work best for them.


Conditions of concern

Since the morning after pill contains estrogen and progestin, the same hormones as birth control pills, women who normally take birth control pills should safely be able to take emergency contraceptive pills. However, taking drugs with these hormones may be risky for women with certain conditions.

Patients may be advised not to take the morning after pill if they have been diagnosed with any of the following conditions:

  • Thyroid disease
  • Breast, cervical, uterine or liver cancer in the personal or family medical history
  • Deep vein thrombosis or any other blood clot disorders
  • History of stroke
  • Ischemic heart disease, including coronary artery disease
  • Heart failure
  • Kidney failure
  • Hepatitis
  • Depression
  • Migraine headaches
  • Abnormal changes in menstrual or uterine bleeding
  • Endometriosis
  • Fibroid tumors of the uterus
  • Heart or circulation problems

The use of emergency contraceptive pills is also a concern in women with other conditions, including:

  • Family history of heart disease
  • High blood pressure
  • High blood cholesterol
  • Diabetes
  • Non-cancerous breast disease (fibrocystic breasts)
  • Gallbladder disease or gallstones
  • Liver disease
  • Epilepsy
  • Lupus
  • Sickle cell anemia
  • Chorea gravidarum (chorea [a condition causing jerky body movements] occurring during pregnancy)

Women are also encouraged to speak with their physician before taking the morning after pill if they are currently breastfeeding, or if they smoke. For women who are breastfeeding, or cannot take drugs containing estrogen, progestin-only pills may be a safe option. A copper-bearing intrauterine device (IUD) may also be recommended. Women should discuss all medical conditions with their obstetrician-gynecologist (ObGyn). Physicians will use this information to recommend the best method of emergency contraception available for each patient.

Studies have been unable to link the ingestion of these hormones with an increased risk of birth defects. However, women who know that they are pregnant should not take emergency contraceptive pills.

Side effects

Risks and side effects of the morning after pill

The most common side effects of the morning after pill are nausea and vomiting. Physicians often prescribe medications to minimize these effects. Normally the nausea subsides within two days.

Women who are experiencing nausea should not stop taking the pills. Pregnancy may not be prevented if the second dose is skipped. Women who vomit within one hour of taking the pills should contact their obstetrician-gynecologist (ObGyn). They may need to take another dose.

Emergency contraceptive pills can also disrupt a woman’s menstrual cycle. After ingesting the pills, a woman’s next menstrual period may come sooner or later than its normal schedule. In addition, the flow of menstrual blood may be heavier or lighter than normal. Women may also experience spotting before their next period.

Most women, however, have their next menstrual period at the expected time or within one week of the predicted time. Women who do not have their menstrual period within one week of their expected time should contact their physician. This may indicate pregnancy.

Other common side effects of the morning after pill include:

  • Headaches
  • Breast tenderness
  • Dizziness
  • Bloating
  • Abdominal pain
  • Fatigue

In addition to being more effective in preventing pregnancy, morning after pills that contain only progestin also cause fewer side effects.

Questions for your doctor

Patients may wish to ask their doctor or healthcare professional the following questions related to the morning after pill:
  1. Based on my lifestyle and medical history, which morning after pill might be best for me?
  2. How can I obtain the morning after pill?
  3. How effective is the morning after pill for preventing pregnancy?
  4. Can I use the morning after pill to terminate an established pregnancy?
  5. Is the morning after pill safe for me to take?
  6. What risks and/or side effects are associated with the morning after pill?
  7. Will taking the morning after pill affect my fertility in the future?
  8. How soon after unprotected sex should I take the first dose?
  9. When should I take the second dose?
  10. Can any of my current medications interfere with the morning after pill?
  11. Does the morning after pill provide protection from sexually transmitted diseases?

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