Half-used blister pack of LevlenED Contraceptive use<unk> s are a type of oral medication that is designed to be taken every day, at the same time of day, in order to prevent pregnancy. There are many different formulations or brands, but the average pack is designed to be taken over a 28-day period, or cycle. For the first 21 days of the cycle, users take a daily<unk>  that contains hormones (estrogen and progestogen). The last 7 days of the cycle are hormone free days. Some packets only contain 21<unk> s and users are then advised to take no<unk> s for the following week. Other packets contain 7 additional placebo<unk> s, or biologically inactive<unk> s. Some newer formulations have 24 days of active hormone<unk> s, followed by 4 days of placebo (examples include Yaz 28 and Loestrin 24 Fe) or even 84 days of active hormone<unk> s, followed by 7 days of placebo<unk> s (Seasonale). A woman on the<unk>  will have a withdrawal bleed sometime during her placebo<unk>  or no<unk>  days, and is still protected from pregnancy during this time. Then after 28 days, or 91 days depending on which type a person is using, users start a new pack and a new cycle. Effectiveness If used exactly as instructed, the estimated risk of getting pregnant is 0.3%, or about 3 in 1000 women on<unk> s will become pregnant within one year. However, typical use is often not exact due to timing errors, forgotten<unk> s, or unwanted side effects. With typical use, the estimated risk of getting pregnant is about 9%, or about 9 in 100 women on<unk>  will become pregnant in one year. The perfect use failure rate is based on a review of pregnancy rates in clinical trials, the typical use failure rate is based on a weighted average of estimates from the 1995 and 2002 U.S. National Surveys of Family Growth (NSFG), corrected for underreporting of abortions. Several factors account for typical use effectiveness being lower than perfect use effectiveness: * mistakes on the part of those providing instructions on how to use the method * mistakes on the part of the user * conscious user non-compliance with instructions. For instance, someone using oral forms of hormonal birth control might be given incorrect information by a health care provider as to the frequency of intake, forget to take the<unk>  one day, or simply not go to the pharmacy on time to renew the prescription.<unk> s provide effective contraception from the very first<unk>  if started within five days of the beginning of the menstrual cycle (within five days of the first day of menstruation). If started at any other time in the menstrual cycle,<unk> s provide effective contraception only after 7 consecutive days use of active<unk> s, so a backup method of contraception (such as condoms) must be used until active<unk> s have been taken for 7 consecutive days.<unk> s should be taken at approximately the same time every day. The effectiveness of the<unk>  appears to be similar whether the active<unk> s are taken continuously for prolonged periods of time or if they are taken for 21 active days and 7 days as placebo. Contraceptive efficacy may be impaired by numerous means. In any of these instances, a backup method should be used until consistent use of active<unk> s (for 7 consecutive days) has resumed, the interacting drug has been discontinued or illness has been resolved. Factors that may contribute to a decrease in effectiveness: # missing more than one active<unk>  in a packet, # delay in starting the next packet of active<unk> s (i.e., extending the<unk> -free, inactive or placebo<unk>  period beyond 7 days), # intestinal malabsorption of active<unk> s due to vomiting or diarrhea, # drug interactions with active<unk> s that decrease contraceptive estrogen or progestogen levels. According to CDC guidelines, a<unk>  is only considered 'missed' if 24 hours or more have passed since the last<unk>  taken. If less than 24 hours have passed, the<unk>  is considered "late". Role of placebo<unk> s The role of the placebo<unk> s is two-fold: to allow the user to continue the routine of taking a<unk>  every day and to simulate the average menstrual cycle. By continuing to take a<unk>  every day, users remain in the daily habit even during the week without hormones. Failure to take<unk> s during the placebo week does not impact the effectiveness of the<unk> , provided that daily ingestion of active<unk> s is resumed at the end of the week. The placebo, or hormone-free, week in the 28-day<unk>  package simulates an average menstrual cycle, though the hormonal events during a<unk>  cycle are significantly different from those of a normal ovulatory menstrual cycle. Because the<unk>  suppresses ovulation (to be discussed more in the Mechanism of action section), birth control users do not have true menstrual periods. Instead, it is the lack of hormones for a week that causes a withdrawal bleed. The withdrawal bleeding that occurs during the break from active<unk> s has been thought to be reassuring, a physical confirmation of not being pregnant. The withdrawal bleeding is also predictable. Unexpected breakthrough bleeding can be a possible side effect of longer term active regimens. Since it is not uncommon for menstruating women to become anemic, some placebo<unk> s may contain an iron supplement. This replenishes iron stores that may become depleted during menstruation. As well, birth control<unk> s, such as<unk> s, are sometimes fortified with folic acid as it is recommended to take folic acid supplementation in the months prior to pregnancy to decrease the likelihood of neural tube defect in infants. No or less frequent placebos If the<unk>  formulation is monophasic, meaning each hormonal<unk>  contains a fixed dose of hormones, it is possible to skip withdrawal bleeding and still remain protected against conception by skipping the placebo<unk> s altogether and starting directly with the next packet. Attempting this with bi- or tri-phasic<unk>  formulations carries an increased risk of breakthrough bleeding and may be undesirable. It will not, however, increase the risk of getting pregnant. Starting in 2003, women have also been able to use a three-month version of the<unk> . Similar to the effect of using a constant-dosage formulation and skipping the placebo weeks for three months, Seasonale gives the benefit of less frequent periods, at the potential drawback of breakthrough bleeding. Seasonique is another version in which the placebo week every three months is replaced with a week of low-dose estrogen. A version of the combined<unk>  has also been packaged to eliminate placebo<unk> s and withdrawal bleeds. Marketed as Anya or Lybrel, studies have shown that after seven months, 71% of users no longer had any breakthrough bleeding, the most common side effect of going longer periods of time without breaks from active<unk> s. While more research needs to be done to assess the long term safety of using<unk> 's continuously, studies have shown there may be no difference in short term adverse effects when comparing continuous use versus cyclic use of birth control<unk> s. Non-contraceptive use The hormones in the<unk>  have also been used to treat other medical conditions, such as polycystic ovary syndrome (PCOS), endometriosis, adenomyosis, acne, hirsutism, amenorrhea, menstrual cramps, menstrual migraines, menorrhagia (excessive menstrual bleeding), menstruation-related or fibroid-related anemia and dysmenorrhea (painful menstruation). Besides acne, no oral contraceptives have been approved by the U.S. FDA for the previously mentioned uses despite extensive use for these conditions. PCOS PCOS, or polycystic ovary syndrome, is a syndrome that is caused by hormonal imbalances. Women with PCOS often have higher than normal levels of estrogen all the time because their hormonal cycles are not regular. Over time, high levels of uninhibited estrogen can lead to endometrial hyperplasia, or overgrowth of tissue in the uterus. This overgrowth is more likely to become cancerous than normal endometrial tissue. Thus, although the data varies, it is generally agreed upon by most gynecological societies that due to the high estrogen levels that women with PCOS have, they are at higher risk for endometrial hyperplasia. To reduce this risk, it is often recommended that women with PCOS take hormonal contraceptives to regulate their hormones. Both<unk> s and progestin-only methods are recommended.<unk> s are preferred in women who also suffer from uncontrolled acne and symptoms of hirsutism, or male patterned hair growth, because<unk> s can help treats these symptoms. Endometriosis For pelvic pain associated with endometriosis,<unk> s are considered a first-line medical treatment, along with NSAIDs, GnRH agonists, and aromatase inhibitors.<unk> s work to suppress the growth of the extra-uterine endometrial tissue. This works to lessen its inflammatory effects.<unk> s, along with the other medical treatments listed above, do not eliminate the extra-uterine tissue growth, they just reduce the symptoms. Surgery is the only definitive treatment. Studies looking at rates of pelvic pain recurrence after surgery have shown that continuous use of<unk> s is more effective at reducing the recurrence of
Combined oral contraceptive pill
Oral contraceptive pill
Male contraceptive
Extended cycle combined hormonal contraceptive
Estradiol-containing birth control pill
Heat-based contraception
Female condom
Combined hormonal contraception