Oral contraceptives (commonly known as "The Pill") were designed to give women a way to create the same effect as that which naturally occurs during pregnancy without actually being pregnant. Scientists discovered that when a woman takes synthetic versions of the hormones that naturally increase at pregnancy, ovulation ceases.  When taken as directed, most Pills prevent ovulation. When no egg is released, pregnancy does not occur.

In addition to oral contraceptives (OCs), a few other hormone-based products have become available in recent years, including hormone injections, the vaginal ring and the patch. All of these work in much the same way as the Pill, except they deliver hormones to the body in a different way.
 
When taken as directed, most women on the Pill do not ovulate.
 
The Period That Isn't
When women take the Pill as directed, most do not ovulate, and therefore, do not build up a thicker uterine lining which they need to shed along with an unfertilized egg--the purpose of a real menstrual period. The monthly bleeding women on the Pill experience is not a real "menstrual period," but actually a "withdrawal bleed" induced by the withdrawal of synthetic hormones during the Pill-free or placebo week.
 
Important Differences
The withdrawal bleeding women typically experience during the Pill-free or placebo week of the Pill regimen tends to be comparatively more predictable and lighter than a menstrual period. This symptom relief is most likely the result of the fact that women on the Pill are not ovulating or experiencing a real "biological" menstrual period.

A Gentler Experience
The creation of the monthly "withdrawal bleed" associated with the Pill was based on the perspective of those who invented it in the early 1960s. By developing the Pill to include one week of placebo or inactive pills per month, women still had the experience of a monthly bleed, simply a withdrawal symptom caused by taking pills not containing active hormones one week out of every cycle.  In this way, the Pill still prevented ovulation while maintaining what appeared to be a monthly period.  Researchers thought women would be most likely to try this then-new concept if it appeared as if they were still getting their monthly period.  Ironically, many experts believe monthly bleeding on the Pill is not medically necessary.

The Pill: Years of Experience
Of all the hormone-based contraceptives on the market, the Pill has been available and studied the longest--more than 40 years; it is the most commonly-used form of reversible birth control. The Pill is very effective if taken the same time every day--more than 99 percent. Research also shows that it offers non-contraceptive benefits, including increased cycle regularity, and decreased incidence of dysmenorrhea (menstrual cramps), blood loss and iron-deficiency anemia.  In other words, women on the Pill often have lighter flow, less cramps, and other menstrual symptoms are usually less severe.  Other non-contraceptive benefits include decreased incidence of the following: ovarian cysts, ectopic pregnancies, endometrial and ovarian cancers, pelvic inflammatory disease (PID), and fibrodenomas and fibrocystic disease of the breasts.
 
The monthly bleeding on the Pill is not a real "menstrual period," but actually a "withdrawal bleed" induced by the reduction of hormones during the Pill-free or placebo week.
 
 
After 40 years of study, women can feel confident oral contraceptives are a safe and effective method of pregnancy prevention.  Whenever choosing a form of birth control, it's important to be aware of risks as well as benefits. Most side effects of the Pill are not serious.  And those that are serious occur infrequently.  Serious risks, which can be life threatening, include blood clots, stroke and heart attack and are increased for women who smoke cigarettes.  Cigarette smoking increases the risk of serious cardiovascular effects, especially among women over age 35.  Women who use oral contraceptives are strongly advised not to smoke.  

Women who have had a heart attack, stroke, blood clots, certain cancers or liver diseases, unexplained vaginal bleeding, or who are or may be pregnant should not use the Pill. And, oral contraceptives do not protect against HIV infection (AIDS) or other sexually transmitted infections. Since every woman is unique, you should talk to your healthcare professional about how risks relate to your use of the Pill.  Oral contraceptives are not for everyone.  Typically, however, risks associated with the Pill are lower than those associated with pregnancy, which oral contraceptives are designed to prevent.

New Options on the Horizon
Currently, while oral contraceptives are not approved by the Food and Drug Administration (FDA) to decrease the frequency of bleeding, a new extended cycle oral contraceptive, which by design limits the number of periods, is currently being studied and is under review by the FDA.
 
Choosing a birth control option is a very personal decision. The good news is women today have many options, and the choices are increasing. Your healthcare professional can answer any questions you may have.
 
It is estimated that more than 16 million women currently take oral contraceptives in the United States. Oral contraceptives are not for every woman. Serious risks associated with birth control pills that can be life threatening include blood clots, stroke and heart attack. These risks are increased in women who smoke cigarettes, especially women over 35. Women who use oral contraceptives should not smoke. Some women should not use birth control pills, including women who have had a heart attack, stroke, blood clots, certain cancers or liver diseases, unexplained vaginal bleeding, and those who are or may be pregnant. Birth control pills do not protect against HIV infection (AIDS) or other sexually transmitted diseases.
 
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