Definition and facts about hormonal methods of birth control
- "The pill" was introduced in the United States in 1962 and signaled the beginning a new era for women, as they were now able, for the first time, to reliably control their fertility.
- According to the Centers for Disease Control and Prevention, the pill represents the leading
birth control method used by US women younger than 30 years of age. Longer-acting implants, injections, rings, and patches that employ hormones to prevent ovulation or to create a hostile environment for sperm are also available.
- There are several types of hormonal birth control methods, for example:
- Side effects of hormonal methods of birth control depend upon the
method, but may include:
- No birth control method is 100% effective.
- Birth control does not protect a person from contracting sexually
transmitted diseases (STDs).
- The ultimate decision of which birth control method to use is best made by each individual woman in consultation with her health-care
professional. Each method has risks, benefits, advantages, and disadvantages.
Birth control pills
Birth control pills, also known as oral contraceptives, have been marketed in the United States since 1962. Over the past 40 years, the type of estrogen and progestin (hormones) used in the pills has been altered and the amounts/potencies of hormones in these products has been decreased.
Birth control pills today are designed so as to enhance safety and reduce side effects. Lower doses of estrogen are associated with a decrease in side effects, such as weight gain, breast tenderness, and nausea.
Birth control pills are taken by mouth and swallowed with a liquid. Several types of birth control pills are chewable. These pills contain the same hormones, progestin and estrogen, that are present in standard birth control pills. Some packages contain 21 active pills and 7 inactive pills to be taken throughout one menstrual cycle. You may chew the pills or swallow them whole. If you chew the pill, you should drink eight ounces of water afterward to make sure the full dose is absorbed from your stomach. The chewable version has similar side effects to other birth control pills, such as an increased risk for blood clots, heart attacks, and strokes.
What are the side effects of birth control pills?
Side effects related to birth control usage include
- breast tenderness,
- breakthrough bleeding,
- absence of menstrual flow,
- anxiety, and
- diminished sexual desire.
- Birth control pills do not consistently provide protection from
sexually transmitted diseases (STDs). Taking the pills daily and consistently (the same time every day) is important. If the birth control pill is stopped, it may take several months for ovulatory menstrual cycles to resume. If menstrual periods have not resumed within six months of stopping oral contraceptives her health-care professional
should be contacted for evaluation.
What if I miss taking one of my birth control pills?
If a woman misses 1 or 2 pills, she should take 1 tablet as soon as she remembers. She then takes 1 tablet twice daily until each of the missed pills has been accounted for. Women who have missed more than 2 consecutive pills should be advised to use a backup method of birth control and finish her pack of pills until the onset of her next menses. The pills work primarily by preventing ovulation (release of an egg from the ovary).
What are the types and brands of birth control pills available in the US?
Over 60 different combinations of birth control pills are available in the
United States. Many of the combinations of these pills have 21 hormonally active pills followed by seven pills containing no hormones. A woman begins taking a pill on the first day of her period or the first Sunday after her period has begun. By taking a pill a day, a woman can usually take pills consistently throughout her cycle.
There are a variety of types of birth control pills. Three of these include monophasic, biphasic, and
Monophasic pills: These have a constant dose of both estrogen and progestin in each of the hormonally active pills.
Phasic pills (biphasic and triphasic): In these combination pills, the dosage of one or both hormones changes so as to mimic a normal menstrual cycle.
- Effectiveness of birth control pills:
Pregnancy rates range from 0.1% with perfect use to 5% with typical use.
- Advantages of birth control pills: Birth control pills are used to treat irregular menstrual periods. Women can manipulate the cycle to avoid a period during certain events, such as vacations or weekends by extending the number of days of hormonally active pills or by skipping the inert pill week. Birth control pills prevent certain conditions, such as
benign breast disease,
pelvic inflammatory disease (PID), and functional
ovarian cyst formation. Functional cysts are prevented by the suppression of stimulation of the ovaries. Ectopic pregnancies cannot occur as ovulation does not occur. Birth control pills have been known to prevent certain ovarian and endometrial cancers.
What Are Your Birth Control Options?
For the individual woman, the ability to effectively control when and whether she becomes pregnant affects her ability to achieve her own goals and contribute to her sense of well-being. A woman's choice of birth control method involves factors such as how easy it is to use, safety, risks, cost, and personal considerations.
There are a variety of types and options to prevent pregnancy, and include:
- Barrier methods (condoms, dental dams)
- Hormonal methods (the pill, patch, ring, etc.)
- Emergency contraception
- Permanent methods (tubal ligation and vasectomy)
- Behavioral methods (abstinence, natural family planning)
What are the risks of taking birth control pills?
- Some women may be at risk for
blood clot formation (venous thrombosis). At particular risk are heavy smokers (especially those older than 35 years), women with high or abnormal blood
lipids (cholesterol levels), and women with severe
high blood pressure, and/or
- The association of birth control pill usage and
breast cancer has been controversial. More recent studies have shown that birth control pill usage does not increase the risk of
- The relationship between birth control pill use and
cervical cancer also
is somewhat controversial.
- Risk factors for
cervical cancer include the age at first sexual intercourse and exposure to the
human papillomavirus. The current opinion is that if birth control pills increase the risk of cervical cancer, the risk is small and related to sexual behavior. Thus, women who are sexually active and use birth control pills for
contraception should have a periodic
91-day birth control pills
The FDA has approved several birth control pills that you take for 12 weeks of hormonally active pills (84 days) followed by one week (seven days) of an inactive pill. A menstrual period occurs during that week, so that a period occurs only once every three months. These extended-cycle pills contain the same hormones which are found in the 28 day cycle pills.
Although users of these products have fewer scheduled menstrual cycles, the data from clinical trials has shown that many women, especially in the first few cycles of use, had more unplanned bleeding and spotting between the expected menstrual periods than women taking a conventional 28-day cycle birth control pill.
These pills are effective for prevention of pregnancy when used as directed.
- The risks of using these products are similar to the risks of other birth control pills and include an increased risk of blood clots, heart attack, and stroke.
- The labeling also carries the warning that
cigarette smoking increases the risk of serious heart-related side effects from the use of combination estrogen-and progestin-containing contraceptives, particularly in users over the age of 35.
- Because users can expect to have fewer periods, the label also advises women to consider the possibility of pregnancy if they miss any anticipated periods.
Progestin-only birth control pills
Progestin-only pills, also known as mini-pills, are not widely used in the United States. Fewer than 1% of oral contraceptive users employ them as their sole method of birth control. Their primary utility is found in women who are breastfeeding or who cannot take estrogen for medical reasons.
Birth control patch
A transdermal contraceptive patch (worn on the skin) that releases estrogen and progesterone directly through the skin (Ortho Evra) is approved for usage in the United States. Each patch contains a one-week supply of hormones. It releases a low daily dose equivalent to the lowest-dose oral contraceptive. The birth control patch is easy for women to use because it works for a week, and women do not have to remember a pill every day. A new patch is applied every week for three weeks, and a patch is not worn during the fourth week, during which a menstrual period occurs. It is available by prescription.
What are the side effects of the birth control patch?
Side effects for the birth control patch are similar to those experienced by women using oral contraceptives. However, the patch may cause skin irritation at the site of application (near the bikini line, on the buttocks, or the lower abdomen). Occasionally they patch may become dislodged, for example, in the shower, and its absence may not be noticed. In August 2002, the FDA listed a failure rate for the patch of one pregnancy per 100 women per year, similar to that of other combination hormonal methods. It may be less effective for women who weigh more than 198 pounds. The patch does not protect against STDs.
The vaginal ring (NuvaRing) is a newer form of birth control. The actual design of a vaginal ring as a birth control device was first developed in the 1970s. The vaginal ring can deliver progesterone or progesterone/estrogen combinations. The hormones are released slowly into the bloodstream. Preliminary studies show that, as with oral contraceptives, they will safely prevent pregnancy with few side effects. The patches would be used in the same schedule as birth control pills, with three weeks of ring usage and one week without to produce a menstrual period. If the ring comes out on its own and remains out for more than three hours, you must use another form of birth control until the ring has been back in place for at least seven days. It is available by prescription. The vaginal ring does not prevent STDs.
Currently, in the United States, an implantable method of birth control is enjoying wide popularity. With this form of contraception a small plastic rod containing a form of progesterone is inserted beneath the skin of the upper arm. This product, called Nexplanon, provides consistent birth control for three years. It is inserted by a health-care professional in the office using local anesthetic. It can be removed at any time, whereupon fertility usually returns promptly.
- Effectiveness of the implant: Nexplanon is one of the most effective birth control methods available, with a failure rate less than 0.5% per year. Use by women over 130% of ideal body weight may be associated with an increased failure rate.
- Advantages of the implant: Implants last for three years and require no care or maintenance. They are extremely effective. They do not contain estrogen, and can be used by women who need to avoid estrogen, such as
women who are breastfeeding.
- Disadvantages and side effects of the implant: The implants do require a minor surgical procedure for both insertion and removal. Irregular bleeding is the most common side effect leading to early removal of the implant. Other associated problems
- The implant product does not protect against STDs.
Injections and combination injections
An injection of the synthetic hormone medroxyprogesterone acetate (DMPA, Depo-Provera) can be administered every 3 months to inhibit ovulation and, thus, provide contraception. The injection is given at a doctor's office. Following the injection, the medication is active within 24 hours and lasts for 3 months.
- Effectiveness: DMPA is an extremely effective contraceptive option. Most other medications or patient weight do not diminish its efficacy. The use failure rate with this method is reported to be 0.3% during the first year of use.
- Advantages: DMPA does not produce serious side effects such as those caused by estrogen. It acts to lower the risk for certain endometrial and ovarian cancers. This method also acts to thin the uterine lining so that, for many
women, menstrual bleeding may cease altogether.
- Disadvantages and side effects: Following cessation of
Depo-Provera, in some somen menstrual bleeding may not resume for over a year. In others irregular bleeding may ensue. Irregular menstruation can be treated by giving the next dose earlier or by temporarily adding a low-dose estrogen product. In women who have used DMPA on a long term basis ovulation may be delayed. Thus a return to fertility may also be inhibited until after the long term effects of the drug have subsided. Approximately 70% of former users desirous of pregnancy will conceive within 12 months, and 90% of former users conceive within 24 months. Other side effects, such as weight gain and
depression may continue for as long as 1 year after the last injection. Recent studies suggest a possible link between DMPA and diminished
bone density. This method does not protect against STDs.
Reviewed on 11/20/2017
Medically reviewed by Wayne Blocker, MD; Board Certified Obstetrics and Gynecology
REFERENCE: Samra-Latif, O. M., MD. "Contraception." Medscape. Updated Aug 16, 2016.