Birth Control Pills

Birth Control PillsBirth Control Pills

How do birth control pills work?

Birth control pills contain hormones that prevent ovulation. These hormones also cause other changes in the body that help prevent pregnancy. The mucus in the cervix thickens, which makes it hard for sperm to enter the uterus. The lining of the uterus thins, making it less likely that a fertilized egg can attach to it.

How effective are birth control pills in preventing pregnancy?

With typical use, about 8 in 100 women (8%) will become pregnant during the first year of using this method. When used perfectly, 1 in 100 women will become pregnant during the first year. To be effective at preventing pregnancy, the pill must be taken every day at the same time each day.

Noncontraceptive Benefits of Birth Control Pills

Most women will use birth control pills at some time in their lives. But many women don’t know that birth control pills also can be used to treat a variety of female problems and can have some surprising health benefits. Birth control pills are made of synthetic (laboratory derived) versions of the two ovarian hormones: progesterone and estradiol. Also, birth control pills can contain synthetic forms of both hormones or progesterone (progestin) only. Progestin-only pills are best for women who should not or do not want to take estrogen, but are not used as much because they have a higher rate of causing unpredictable vaginal bleeding for at least the first year.

How do birth control affect a womens period?

To understand how birth control pills affect periods, it is helpful to understand how the normal menstrual cycle works. A menstrual period takes place when the uterus (womb) sheds its lining; this process is controlled by the hormones made by the ovary (estrogen and progesterone). A menstrual cycle begins with the first day of the period, lasts for about one month and is divided into two halves by ovulation (the release of an egg from the ovary). During the first half of the cycle, only estrogen is made. Under the influence of estrogen, the uterine lining grows to prepare for a potential pregnancy. During the second half of the cycle, after ovulation, progesterone is also made. Progesterone stops the lining from growing and prepares it for implantation of an embryo. If pregnancy does not occur, progesterone and estrogen levels fall, which triggers the shedding of the uterine lining and the next period begins.

What are the different types of birth control pills?

There are two basic types of birth control pills: 1) combination pills, which contain the hormones estrogen and progestin, and 2) progestin-only pills.

What are continuous-dose pills?

Continuous-dose pills are a type of combination pill. They also are called extended-cycle pills. These pills reduce the number of menstrual periods a woman has or stop them altogether.

How do I start combination pills?

There are different options for starting the combination pill. You can start taking the pill on the first day of your menstrual period. Another option is to start taking the pill on ta Sunday after your menstrual period starts. With this method, you need to use a backup birth control method for the next 7 days of the first cycle. No matter which day you choose to start taking the pill, you will start each new pack of pills on the same day of the week as you started the first pack.

How do I take 21-day combination pills?Birth Control Pills

Take one pill at the same time each day for 21 days. Wait 7 days before starting a new pack. During the week you are not taking the pill, you will have bleeding.

How do I take 28-day combination pills?

Take one pill at the same time each day for 28 days. Depending on the brand, the first 21 pills or 24 pills contain estrogen and progestin. The remaining pills may be estrogen-only pills, pills that contain a dietary supplement but no hormones, or “inactive” (containing no hormones or supplements) pills. During the days you are taking the hormone-free pills, you will have bleeding.

How do I take 3-month combination pills?

Take one pill at the same time each day for 84 days. Depending on the brand, the last seven pills either contain no hormones or contain estrogen. With both brands, you will have bleeding on these days every 3 months.

How do I take 1-year combination pills?

Take one pill at the same time each day for a year. In time, bleeding will be less and may even stop.

Can other medications change the effectiveness of the combination pill?

Certain drugs may interfere with the effectiveness of the pill. These include two antibiotics (rifampin and griseofulvin), some seizure medications, and some drugs used to treat human immunodeficiency virus (HIV).

Are there benefits to taking the combination birth control pill?

The combination birth control pill has health benefits in addition to preventing pregnancy. The pill helps to keep bleeding cycles regular, lighter, and shorter and reduces cramps. It can be used in the treatment of certain disorders that cause heavy bleeding and menstrual pain, such as fibroids and endometriosis. Some pills may help control acne. Combination pills also may decrease the risk of cancer of the uterus and ovary and improve bone density during perimenopause.

What are the risks of combination pill use?

Combination birth control pills are safe for most women. However, they are associated with a small increased risk of deep vein thrombosis, heart attack, and stroke. The risk is higher in some women, including women older than 35 years who smoke more than 15 cigarettes a day or women who have multiple risk factors for cardiovascular diseases, such as high cholesterol, high blood pressure, and diabetes. Discuss your individual risks for these complications with your health care provider before deciding to use combination birth control pills.

How do I take progestin-only pills?

The progestin-only pill comes in packs of 28 pills. All the pills in the pack contain hormones. One pill is taken per day. It is important to take progestin-only pills at the same time each day. If a pill is missed by more than 3 hours or if vomiting occurs after taking a pill, you should take another pill as soon as possible and use a backup method of contraception for the next 48 hours.

What are the benefits of progestin-only pills?

The progestin-only pill may be a better choice for women who have certain health problems, such as blood clots, and cannot take pills with estrogen. Progestin-only pills usually can be used soon after childbirth by women who are breastfeeding.

Who should not take progestin-only pills?

Progestin-only pills may not be a good choice for women who have certain medical conditions, such as liver tumors or lupus. Women who have breast cancer should not take progestin-only pills.

What should I do if I miss a pill?

You should know what to do if you miss a pill. The procedure differs with each type. Read the directions that come with your pills carefully. You also may want to call your health care provider. With some types of pills and depending on how many pills are missed, you may need to use a backup method of birth control or consider emergency contraception.

What side are effects associated with taking birth control pills?

When beginning any birth control pill, there is a high likelihood of breakthrough bleeding during the first few months of use. Breakthrough bleeding is a normal and usually temporary side effect as the body adjusts to a change in hormone levels. It may last longer than a few months with continuous-dose pills.
Most side effects are minor and often go away after a few months of use. There will likely be fewer side effects if the pill is taken at the same time every day. The most common side effects of using birth control pills include the following:

  • A headacheBirth Control Pills
  • Breast tenderness
  • Nausea
  • Irregular bleeding
  • Missed periods
  • Weight gain (progestin-only pills)
  • Anxiety or depression (progestin-only pills)
  • Excessive body hair growth (progestin-only pills)
  • Acne (progestin-only pills)

What are other benefits of Birth Control Pills

Regulation of menstrual periods:

Most combination birth control pills contain three weeks of active pills (those that contain hormones) and one week of inactive placebo pills (those that do not contain hormones). The bleeding of the period occurs when the hormones are no longer taken during the week that the sugar or placebo pills are taken. A woman can increase the length of time between periods by taking active pills for more weeks. Some drug companies make pill packs that contain up to 3 months of continuous active pills. Women on these pills only have four periods a year, which can be convenient during such times as final exams, sports activities, or social events.

Treatment of irregular periods:

Birth control pills can be used to make irregular or unpredictable periods occur on a monthly basis. Women who have menstrual cycles longer than 35 days might not be making progesterone, which prevents the uterine lining from growing too much. Excess growth of the uterine lining can cause heavy bleeding or increase the risk for developing abnormal patterns of growth in the uterine lining, including cancer. The most common reason for irregular and infrequent periods is Polycystic Ovary Syndrome (PCOS). Because a birth control pill contains progesterone-like medication, it can help regulate the menstrual cycle and protect the lining of the uterus against pre-cancer or cancer.

Treatment of heavy periods (menorrhagia):

Birth control pills contain a progesterone-like hormone, which makes the lining of the uterus thinner and causes lighter bleeding episodes. In rare cases, some women may not experience bleeding during the period in which they take the placebo or sugar pills. Currently marketed pills allow a woman to have a period every month, every 90 days, or once per year, as desired.

Treatment of painful periods (dysmenorrhea):

A chemical called prostaglandin is produced in the uterus at the time of the period, and can cause painful menstrual periods. Prostaglandin can cause contractions of the uterus that produce the menstrual cramping that most women experience. Women who produce high levels of prostaglandin have more intense contractions and more severe cramping. Birth control pills prevent ovulation which in turn reduces the amount of prostaglandin produced in the uterus. By doing so, birth control pills relieve menstrual cramping.

Treatment of endometriosis:

Another cause of painful menstrual cycles is endometriosis. When the tissue lining the uterus (endometrium) grows outside of the uterus it is called endometriosis. Just as progesterone limits the growth of the uterine lining, the progesterone-like hormones in birth control pills can limit or decrease the growth of endometriosis. Because of this, birth control pills can reduce the pain associated with endometriosis for many women.

Treatment of premenstrual syndrome (PMS) and premenstrual dysphoric disorder (PMDD):

Many women who have PMS or PMDD report an improvement in their symptoms while they are taking birth control pills. It is thought that birth control pills prevent the symptoms of PMS and PMDD by stopping or preventing ovulation from taking place.

Treatment for acne, hirsutism (excess hair) and alopecia (hair loss):

All birth control pills can improve acne and hair growth in the midline of the body (hirsutism) by reducing the levels of male hormones (androgens) produced by the ovary. All women make small amounts of androgens in the ovaries and adrenal glands. When these hormones are made in higher than normal amounts, or if a woman is sensitive to the androgens produced, she may start to grow hair above the lip, below the chin, between the breasts, between the belly button and pubic bone, or down the inner thigh. Birth control pills reduce production of male hormones and increase the production of the substances in the body that bind the androgens circulating in the bloodstream. Within six months of use, there is usually a reduction in the abnormal hair growth. However, when a woman has more excessive male hormone symptoms, she should see a gynecologist or primary care doctor. These symptoms may include male pattern baldness, smaller breast size, increased muscle mass, growth of the clitoris, or lowering of the pitch of the voice.

Other health benefits of birth control pills:

Women who have used birth control pills have been found to have fewer cases of anemia (low red blood cells), ovarian cancer, and uterine cancer. These beneficial effects occur because the birth control pill works by decreasing the number of ovulations, amount of menstrual blood flow, and frequency of periods.


Antibiotics: Drugs that treat infections.
Breakthrough Bleeding: Vaginal bleeding at a time other than the menstrual period.
Cardiovascular Disease: Disease of the heart and blood vessels.
Cervix: The opening of the uterus at the top of the vagina.
Deep Vein Thrombosis: A condition in which a blood clot forms in veins in the leg or other areas of the body.
Emergency Contraception: Methods that are used to prevent pregnancy after a woman has had sex without birth control, after the method she used has failed, or if a woman is raped. Emergency contraception methods include progestin-only pills, ulipristal, birth control pills taken in specific amounts, or a copper intrauterine device. The pills must be taken within 120 hours to reduce the risk of pregnancy.
Endometriosis: A condition in which tissue similar to that normally lining the uterus is found outside of the uterus, usually on the ovaries, fallopian tubes, and other pelvic structures.
Estrogen: A female hormone produced in the ovaries.
Fibroids: Benign growths that form in the muscle of the uterus.
Hormones: Substances produced by the body to control the functions of various organs.
Human Immunodeficiency Virus (HIV): A virus that attacks certain cells of the body’s immune system and causes acquired immunodeficiency syndrome (AIDS).
Ovulation: The release of an egg from one of the ovaries.
Perimenopause: The period around menopause that usually extends from age 45 years to 55 years.
Progestin: A synthetic form of progesterone that is similar to the hormone produced naturally by the body.
Uterus: A muscular organ located in the female pelvis that contains and nourishes the developing fetus during pregnancy.
If you have further questions, schedule an appointment with Embry Women’s Health.


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