When taken correctly, birth control pills allow women the freedom to enjoy sex with only a minimal risk of becoming pregnant. Birth control pills also offer a number of significant health benefits when taken for at least 10 years, including a significantly lower risk of colorectal, uterine or ovarian cancer. However, they also carry an increased risk of blood clots, ischemic stroke and elevated blood pressure. There has also been widespread concern that birth control pills increase a women’s risk for breast cancer if taken for more than 10 years. However, the data on this are conflicting, and there is no solid link proven between breast cancer and oral contraception. In the long-term Nurses' Health Study, there was no link between breast cancer and even long-term use of birth control pills, while other studies have shown a tiny increase in risk.

Before prescribing birth control pills, a physician will typically conduct a medical history and discuss any risk factors for possible side effects. The most important risk factor is smoking. Many studies have confirmed that women over the age of 35 who smoke more than 15 cigarettes a day are at increased risk for a variety of negative side effects, including cardiovascular conditions. All women are also encouraged to follow-up with their gynecologist regularly.

Also known simply as “the Pill,” birth control pills are made of low doses of synthetic female hormones (usually a combination of estrogen and progestin, a synthetic progesterone). They are designed to prevent ovulation – the process by which an egg leaves an ovary and travels to where it could become fertilized, leading to pregnancy. The pills also suppress the hormones that ready the uterus to receive the fertilized egg and establish pregnancy. In doing so, they actually “fool” the body into thinking that the woman is already pregnant, which creates an environment making fertilization difficult.

The pill is more than 99 percent effective in preventing pregnancy when taken correctly, which means that women must be mentally and physically able to unfailingly take the correct pill at about the same time every day. When first introduced, birth control pills had a number of side effects. However, today’s pills use much lower hormone levels than in the past, and this has greatly increased their safety profile. For example, the estrogen levels in many forms of the pill have been reduced from 50 micrograms to 35 or less. Though today’s low-dose pills (third-generation birth control pills) are safe and effective for the majority of women who take them, a woman with any of the following conditions should talk with her physician before taking birth control pills:

Women are also encouraged to speak with their physician before taking birth control pills if they are currently breast-feeding or have any of the following risk factors for cardiovascular disease:

• Smoking, especially if they are over 35 and/or smoking 15 or more cigarettes per day
  
  
• Diabetes
  
  
• High blood pressure (hypertension)
  
  
• A family history of heart disease
  
  
• High triglyceride levels

Among these, high triglyceride levels and heavy smoking among women over age 35 may be contraindications to birth control pills. Other factors that will usually prohibit a woman from taking birth control pills include a history of stroke, a history of estrogen-dependent cancers, liver disease, abnormal uterine bleeding and pregnancy.

Birth control pills do not protect against sexually transmitted diseases, and women are encouraged to speak with their gynecologist for more information about safe sex.

Taking birth control pills offers women a number of significant health benefits. As documented in the package insert of every pack of pills, taking the pills reduces a woman’s risk of the following conditions:

• Colorectal cancer
• Ovarian cancer (when taken for more than 10 years)
• Ovarian cysts
• Pelvic inflammatory disease
• Uterine cancer

Furthermore, birth control pills can regulate a woman’s menstrual cycle, and some forms can help prevent acne.

Early birth-control pills tripled women’s risk of having a stroke, and it was believed that newer, low-dose pills would no longer carry such a cardiovascular risk. However, recent research has shown that even today’s low-dose pills can increase a woman’s risk for ischemic stroke. Experts assure that the risk is still very small, and the presence of other risk factors (e.g., smoking, obesity or high cholesterol) contribute much more significantly to cardiovascular disease than taking birth control pills.

Other cardiovascular risks associated with taking birth control pills include the formation of blood clots and mildly and temporarily  elevated blood pressure. For this reason, women taking birth control pills will be asked at every annual gynecologist visit whether they have had any leg tenderness or pain, which could be a sign of blood clots in the veins of the leg. Each visit will also include a blood pressure check.

Recently, researchers linked the newest version of oral contraceptives, called “third-generation” oral contraceptives, to an increased risk of developing blood clots in the deep veins of the body as compared to the risk associated with second-generation oral contraceptives. However, this remains controversial and the risk seems more pronounced for women at higher risk of blood clots anyway, including women who are obese or smoke. For healthy women under age 35, the absolute risk of blood clots associated with third-generation birth control pills appears to be extremely small.

Women should talk to their physician about the risks and benefits associated with the different types of oral contraceptives.

Different types of birth control pills contain different hormones. Most prescriptions contain estrogen and progestin, but a few varieties contain only progestin. Progestin-only pills (also called “mini-pills”) always come in 28-day packs, and all the pills in those packs contain progestin. These pills must be taken at just the right time every day. If a woman is late taking the medication by only three hours, she will need to use a backup contraceptive for the next two days. Those on the progestin-only pill will have lighter periods or no periods at all, and this pill carries an increased risk of developing gestational diabetes during later pregnancies. In addition, women taking these pills are at higher risk of bleeding, and there is a slightly higher failure rate than with conventional birth control pills. However, for women who cannot be exposed to estrogen, they are an effective option.

Birth control pills that contain both estrogen and progestin come in either 21-day or 28-day cycles. A 21-day cycle means that a patient takes one pill each day for 21 days, and then waits seven days (during which she will get her period) before beginning another pack of 21 pills. A 28-day cycle means that the patient takes a pill a day for 28 days and then starts another pack of 28 pills. The last seven pills in a 28-day pack are taken during the week that she gets her period. These seven pills are a different color than the other pills and contain different ingredients, depending on the particular prescription:

• The last seven pills may be inert (containing no medication). These are also known as “sugar pills.”
  
  
• In other prescriptions, the seven pills deliver low doses of estrogen on days 24 to 28.
  
  
• Another type of birth control pill contains iron in the seven “inert” pills. Because women are losing menstrual blood during these seven days, the iron pills can help maintain healthy iron levels.

When present, these seven pills are a different color from the other “active” pills in the pack. The active pills contain different dosages of hormones, depending on the prescription. The pills may be:

• Monophasic (one-phase), in which all the “active” pills contain the same dose of hormones.
  
  
• Biphasic (two-phase), in which patients take pills of a certain dose for one phase of the cycle and then a different dose for the other phase. The color of the pills changes as the dose changes.
  
  
• Triphasic (three-phase), in which doses change three times, with the number of days on each dose ranging between five and 10. The color of the pills changes as the dose changes.

Typically, women can begin taking birth control pills the day they get the prescription. Alternatively, some physicians may recommend beginning contraception on the first Sunday after the end of the most recent period. In either case, back-up contraception is recommended to prevent unwanted pregnancy until the birth control becomes effective.

Millions of women take birth control pills without any problems, but the pills can produce reactions and even serious medical complications in some people. These complications include migraines and the formation of blood clots (which can increase the risk of stroke). The risk of these complications is significantly higher for smokers, especially after the age of 35. However, most side effects are relatively minor and tend to subside after the first few months. These side effects include:

• Fatigue or unusual tiredness
• Bloating or swelling (edema)
• Abdominal cramping
• Breast tenderness, swelling or pain
• Nausea or vomiting
• Dizziness
• Mood swings
• Headache

One common myth is that birth control pills cause weight gain. Even many physicians report this side effect to their patients. However, available studies suggest that oral contraception does not, in fact, cause weight gain.

One of the most common side effects of birth control is bleeding during the first three months. This is called spotting when slight or breakthrough when heavy. Women are generally advised by their physician to continue taking the pill as prescribed and wait one week before contacting their physician. After three months, women should definitely report any missed or irregular menstrual periods and any irregular vaginal bleeding that they may experience. Women are also encouraged to practice good dental hygiene because taking birth-control pills has been associated in rare cases with gum problems or a condition called dry socket after a tooth removal.

The most common side effects associated with birth control pills do not require medical attention. However, symptoms that are bothersome should be reported to a physician, and patients should seek immediate emergency medical assistance if they experience any of the following:

• Leg pain or tenderness (which could be a sign of a blood clot)
  
  
• Any possible symptoms of a stroke, which include confusion, Dizziness, nausea and/or vomiting, severe headache or numbness/weakness on one side of the body
  
  
• Chest pain

Patients should consult their physician before taking any other medication (either prescription or over-the-counter), nutritional supplements or herbal remedies. For example, medications such as antibiotics or antiviral medications can reduce the effectiveness of birth control pills and increase the risk of pregnancy.

Birth control pills can increase the risk of side effects from the following medications:

When taken along with birth control pills, other medications can increase the risk of liver damage. They include:

• Hormone replacement therapy or other forms of estrogen.
  
  
• Antiarrhythmics. Medications used to treat arrhythmias (abnormal heart rhythms).
  
  
• Antihypertensives. Medications used to treat high blood pressure (hypertension).
  
  
• Disulfiram. A medication used to help people overcome drinking problems by making the taste of alcoholic beverages unappealing.
  
  
• Narcotic antagonists. Medications that block the effect of narcotic drugs to assist addicts in refraining from drug abuse. It is also used in the treatment of alcoholism.
  
  
• NSAIDs (nonsteroidal anti-inflammatory drugs). Medications used to treat inflammation.
  
  
• Anabolic steroids. Medications similar to the male hormone testosterone that are used to rebuild weak body tissue due to a serious injury or illness. They are used in the treatment of certain types of infections, anemia, cancers and edema.
  
  
• Androgens. Male hormones that are used in the treatment of developmental or hormonal conditions in men and some forms of breast cancer in women.
  
  
• Barbiturates. Medications once commonly used in the treatment of anxiety, tension, insomnia, epilepsy and other conditions. Because this medication is easily habit-forming, it has generally been replaced by less addictive medications.
  
  
• Anticonvulsants. Medications used to control or prevent seizures (convulsions).
  
  
• Gold compounds. Medications used in the treatment of rheumatoid arthritis.
  
  
• Antifungals. Medications used to treat fungal infections.
  
  
• Antiprotozoals. Medications used to treat parasite infections.
  
  
• Phenothiazines. Medications used to treat some mental disorders, including schizophrenia and psychosis.
  
  
• Antibacterials. Medications administered to treat bacterial infections or to prevent infections in high-risk individuals, such as those with HIV/AIDS.
  
  
• Some migraine medications.
  
  
• Some muscle relaxants.
  
  
• Some cancer-fighting medications.

Birth control pills take time to work. Though most pills will be effective in most women after seven days, it is recommended that women continue to use another form of birth control while taking their first full pack of pills.

Patients are encouraged to leave the pills in their original container, which helps women keep track of their medication. This is vital because the pills must be taken on time (ideally no more than 24 hours apart) and in proper order to ensure their effectiveness.

To prevent lapses in taking the medication, patients are advised to have an extra month’s supply on hand at all times, replacing it each month.

Women on birth control pills will need to see their gynecologist once a year, and some women may need more frequent follow-up visits. Women should immediately stop taking birth control pills if they become pregnant, or suspect they might be pregnant, to prevent serious consequences for the unborn child.

Women who recently delivered a baby and who are not breastfeeding may resume taking birth control pills two weeks after the birth. However, pills that contain estrogen are not recommended while breastfeeding because they can decrease the amount or quality of breast milk or even pass through the milk into the feeding infant. Some physicians prescribe progestin-only pills for breastfeeding mothers, but recent research has suggested that this practice may increase women’s risk of diabetes if they had gestational diabetes during their pregnancy, although more studies are necessary to confirm this link.

The most common reason for prescribing birth control pills is to prevent pregnancy. However, there are some conditions that are treated with oral contraceptives. These include:

Women who do not take birth control pills regularly can use them in a one-time emergency if they had unprotected sex but do not want to become pregnant. Their physician can quickly prescribe birth control pills, telling them to take one dose as soon as possible and then another dose 12 hours later. The number of pills needed to equal a “dose” usually range between one and five, depending on the type of pills prescribed. Both doses need to be taken within 72 hours of unprotected sex, and women are strongly encouraged to take them with food to reduce the risk of nausea and/or vomiting. However, this method will not work if patients have been taking birth control pills regularly or if taken more than one time during a one-month period.

In addition to birth control pills, there are several other hormone-based birth control methods. They include progestin implants, skin patches and injections for women, and researchers are also working on an oral contraceptive for men. Implants may provide protection from unwanted pregnancy for three years by releasing controlled doses of progestin. The most common reported side effect was unwanted bleeding.

Patches are also an option. Patches can provide estrogen and progestin doses similar to oral contraceptives. Patches are usually changed weekly for three weeks, followed by one week without a patch. Because of differences in the way hormones are administered, patches may be associated with a slightly higher risk of blood clots than oral contraceptives.

Progestin injections are administered every two to three months by a health care professional. Injections are effective, convenient and require less maintenance than birth control pills. However, women have to wait far longer after their last dose to become pregnant. On average, women may experience infertility for 10 months following their last dose, but this can persist for up to 22 months. For this reason, injections are not recommended for women who plan to become pregnant within two years. Side effects are similar to implants. Most women stop menstruating within a year of beginning progestin injections. There have been rare reports of strokes, and women with histories of high blood pressure are encouraged to seek other birth control options.

Additional delivery methods of hormonal contraception have recently become available or are under study, including a vaginal ring and longer-lasting injections.

Preparing questions in advance can help patients to have more meaningful discussions with their physicians regarding their conditions. Patients may wish to ask their doctor the following oral contraception-related questions:

1. Will taking birth control pills prevent or delay menopause?
   
   
2. When I stop taking the Pill, how long do I have to wait before I become pregnant? Do I have to wait?
   
   
3. Is there any risk of miscarriage if I get pregnant in the first month after discontinuing the Pill?
   
   
4. If I'm worried about getting pregnant, can I take several birth control pills the morning after to prevent pregnancy?
   
   
5. If the Pill has decreased my sex drive, can I switch to another form of hormonal birth control to help?
   
   
6. What if I want fewer periods? Can I design a birth control regimen that will safely delay or even stop monthly periods?
   
   
7. What if I accidentally took a few birth control pills while I was in the early stages of a pregnancy?
   
   
8. Will a pregnancy test still work if I'm using birth control pills?
   
   
9. How long until I after I discontinue the Pill until menstruation starts again?
   
   
10. Will my first few periods after discontinuing the Pill be heavier than normal?