Hormonal contraception - wikipedia Hormonal contraception Hormonal Contraception Background Type Hormonal First use 1960 Pregnancy rates ( first year ) Perfect use Varies by method : 0.05 - 2 % Typical use Varies by method : 0.05 - 9 % Usage Duration effect Various Reversibility Upon discontinuation User reminders Must follow usage schedule Advantages and disadvantages STI protection No Periods Frequently lighter, for some methods periods may stop altogether Weight No proven effect Hormonal contraception refers to birth control methods that act on the endocrine system. Almost all methods are composed of steroid hormones, although in India one selective estrogen receptor modulator is marketed as a contraceptive. The original hormonal method -- the combined oral contraceptive pill -- was first marketed as a contraceptive in 1960. In the ensuing decades many other delivery methods have been developed, although the oral and injectable methods are by far the most popular. Altogether, 18 % of the world 's contraceptive users rely on hormonal methods. Hormonal contraception is highly effective : when taken on the prescribed schedule, users of steroid hormone methods experience pregnancy rates of less than 1 % per year. Perfect - use pregnancy rates for most hormonal contraceptives are usually around the 0.3 % rate or less. Currently available methods can only be used by women ; the development of a male hormonal contraceptive is an active research area. There are two main types of hormonal contraceptive formulations : combined methods which contain both an estrogen and a progestin, and progestogen - only methods which contain only progesterone or one of its synthetic analogues ( progestins ). Combined methods work by suppressing ovulation and thickening cervical mucus ; while progestogen - only methods reduce the frequency of ovulation, most of them rely more heavily on changes in cervical mucus. The incidence of certain side effects is different for the different formulations : for example, breakthrough bleeding is much more common with progestogen - only methods. Certain serious complications occasionally caused by estrogen - containing contraceptives are not believed to be caused by progestogen - only formulations : deep vein thrombosis is one example of this. Contents 1 Medical uses 1.1 Polycystic ovary syndrome 1.2 Dysmenorrhea 1.3 Menorrhagia 1.4 Hirsutism 1.5 Effectiveness 1.6 Combined vs. progestogen - only 2 Side - effects 2.1 Cancers 2.2 Cardiovascular disease 2.3 Blood Clots 3 Types 3.1 Combined 3.2 Progestogen - only 3.3 Ormeloxifene 4 Mechanism of action 4.1 Combined 4.2 Progestogen - only 4.3 Ormeloxifene 5 Frequency of use 6 History 7 See also 8 Footnotes Medical uses Hormonal contraception is primarily used for the prevention of pregnancy, but is also prescribed for the treatment of polycystic ovary syndrome, menstrual disorders such as dysmenorrhea and menorrhagia, and hirsutism. Polycystic ovary syndrome Hormonal treatments, such as hormonal contraceptives, are frequently successful at alleviating symptoms associated with polycystic ovary syndrome. Birth control pills are often prescribed to reverse the effects of excessive androgen levels, and decrease ovarian hormone production. Dysmenorrhea Hormonal birth control methods such as birth control pills, the contraceptive patch, vaginal ring, contraceptive implant, and hormonal IUD are used to treat cramping and pain associated with primary dysmenorrhea. Menorrhagia Oral contraceptives are prescribed in the treatment of menorrhagia to help regulate menstrual cycles and prevent prolonged menstrual bleeding. The hormonal IUD ( Mirena ) releases levonorgestrel which thins the uterine lining, preventing excessive bleeding and loss of iron. Hirsutism Birth control pills are the most commonly prescribed hormonal treatment for hirsutism, as they prevent ovulation and decrease androgen production by the ovaries. Additionally, estrogen in the pills stimulates the liver to produce more of a protein that binds to androgens and reduces their activity. Effectiveness Modern contraceptives using steroid hormones have perfect - use or method failure rates of less than 1 % per year. The lowest failure rates are seen with the implants Jadelle and Implanon, at 0.05 % per year. According to Contraceptive Technology, none of these methods has a failure rate greater than 0.3 % per year. The SERM ormeloxifene is less effective than the steroid hormone methods ; studies have found a perfect - use failure rate near 2 % per year. Long - acting methods such as the implant and the IUS are user - independent methods. For user - independent methods, the typical or actual - use failure rates are the same as the method failure rates. Methods that require regular action by the user -- such as taking a pill every day -- have typical failure rates higher than perfect - use failure rates. Contraceptive Technology reports a typical failure rate of 3 % per year for the injection Depo - Provera, and 8 % per year for most other user - dependent hormonal methods. While no large studies have been done, it is hoped that newer methods which require less frequent action ( such as the patch ) will result in higher user compliance and therefore lower typical failure rates. Combined vs. progestogen - only While unpredictable breakthrough bleeding is a possible side effect for all hormonal contraceptives, it is more common with progestogen - only formulations. Most regimens of COCPs, NuvaRing, and the contraceptive patch incorporate a placebo or break week that causes regular withdrawal bleeding. While women using combined injectable contraceptives may experience amenorrhea ( lack of periods ), they typically have predictable bleeding comparable to that of women using COCPs. Although high - quality studies are lacking, it is believed that estrogen - containing contraceptives significantly decrease the quantity of milk in breastfeeding women. Progestogen - only contraceptives are not believed to have this effect. In addition, while in general the progestogen - only pill is less effective than other hormonal contraceptives, the added contraceptive effect of breastfeeding makes it highly effective in breastfeeding women. While combined contraceptives increase the risk for deep vein thrombosis ( DVT - blood clots ), progestogen - only contraceptives are not believed to affect DVT formation. Side - effects Cancers There is a mixed effect of combined hormonal contraceptives on the rates of various cancers, with the International Agency for Research on Cancer ( IARC ) stating : `` It was concluded that, if the reported association was causal, the excess risk for breast cancer associated with typical patterns of current use of combined oral contraceptives was very small. '' and also saying that `` there is also conclusive evidence that these agents have a protective effect against cancers of the ovary and endometrium '' : The ( IARC ) notes that `` the weight of the evidence suggests a small increase in the relative risk for breast cancer among current and recent users '' which following discontinuation then lessens over a period of 10 years to similar rates as women who never used them, as well as `` The increase in risk for breast cancer associated with the use of combined oral contraceptives in younger women could be due to more frequent contacts with doctors '' Small increases are also seen in the rates of cervical cancer and hepatocellular ( liver ) tumours. Endometrial and ovarian cancer risks are approximately halved and persists for at least 10 years after cessation of use ; although `` sequential oral contraceptives which were removed from the consumer market in the 1970s was associated with an increased risk for endometrial cancer ''. Studies have overall not shown effects on the relative risks for colorectal, malignant melanoma or thyroid cancers. Information on progesterone - only pills is less extensive, due to smaller sampling sizes, but they do not appear to significantly increase the risk of breast cancer. Most other forms of hormonal contraception are too new for meaningful data to be available, although risks and benefits are believed to be similar for methods which use the same hormones ; e.g., risks for combined - hormone patches are thought to be roughly equivalent to those for combined - hormone pills. Cardiovascular disease Combined oral contraceptives can increase the risk of certain types of cardiovascular disease in women with a pre-existing condition or already - heightened risk of cardiovascular disease. Smoking ( for women over 35 ), metabolic conditions like diabetes, obesity and family history of heart disease are all risk factors which may be exacerbated by the use of certain hormonal contraceptives. Blood clots Hormonal contraception methods are consistently linked with the risk of developing blood clots. However, the risk does vary depending on the hormone type or birth control method being used. Types There are two main classes of hormonal contraceptives : combined contraceptives contain both an estrogen ( usually ethinylestradiol ) and a progestin. Progestogen - only contraceptives contain only progesterone or a synthetic analogue ( progestin ). Also marketed is ormeloxifene ; while not a hormone, ormeloxifene acts on the hormonal system to prevent pregnancy. Combined The most popular form of hormonal contraception, the combined oral contraceptive pill is known colloquially as the pill. It is taken once a day, most commonly for 21 days followed by a seven - day break, although other regimens are also used. For women not using ongoing hormonal contraception, COCPs may be taken after intercourse as emergency contraception : this is known as the Yuzpe regimen. COCPs are available in a variety of formulations. The contraceptive patch is applied to the skin and worn continuously. A series of three patches are worn for one week each, and then the user takes a one - week break. NuvaRing is worn inside the vagina. A ring is worn for three weeks. After removal, the user takes a one - week break before inserting a new ring. As with COCPs, other regimens may be used with the contraceptive patch or NuvaRing to provide extended cycle combined hormonal contraception. Some combined injectable contraceptives can be administered as one injection per month. Progestogen - only The progestogen only pill ( POP ) is taken once per day within the same three - hour window. Several different formulations of POP are marketed. A low - dose formulation is known as the minipill. Unlike COCPs, progestogen - only pills are taken every day with no breaks or placebos. For women not using ongoing hormonal contraception, progestogen - only pills may be taken after intercourse as emergency contraception. There are a number of dedicated products sold for this purpose. Hormonal intrauterine contraceptives are known as intrauterine systems ( IUS ) or Intrauterine Devices ( IUD ). An IUS / IUD must be inserted by a health professional. The copper IUD does not contain hormones. While a copper - containing IUD may be used as emergency contraception, the IUS has not been studied for this purpose. Depo Provera is an injection that provides three months of contraceptive protection. Noristerat is another injection ; it is given every two months. Contraceptive implants are inserted under the skin of the upper arm, and contain progesterone only. Jadelle ( Norplant 2 ) consists of two rods that release a low dose of hormones. It is effective for five years. Nexplanon has replaced the former Implanon and is also a single rod that releases etonogestrel ( similar to the body 's natural progesterone ). The only difference between Implanon and Nexplanon is Nexplanon is radio opaque and can be detected by x-ray. This is needed for cases of implant migration. It is effective for three years and is usually done in office. It is over 99 % effective. It works in 3 ways : 1. Prevents ovulation - usually an egg does not mature 2. thickens cervical mucus so to prevent sperm from reaching the egg 3. If those 2 fail, the last is the progesterone causes the lining of the uterus to be too thin for implantation. Ormeloxifene Ormeloxifene is a selective estrogen receptor modulator ( SERM ). Marketed as Centchroman, Centron, or Saheli, it is pill that is taken once per week. Ormeloxifene is legally available only in India. Mechanism of action The effect of hormonal agents on the reproductive system is complex. It is believed that combined hormonal contraceptives work primarily by preventing ovulation and thickening cervical mucus. Progestogen - only contraceptives can also prevent ovulation, but rely more significantly on the thickening of cervical mucus. Ormeloxifene does not affect ovulation, and its mechanism of action is not well understood. Combined Combined hormonal contraceptives were developed to prevent ovulation by suppressing the release of gonadotropins. They inhibit follicular development and prevent ovulation as a primary mechanism of action. Progestogen negative feedback decreases the pulse frequency of gonadotropin - releasing hormone ( GnRH ) release by the hypothalamus, which decreases the release of follicle - stimulating hormone ( FSH ) and greatly decreases the release of luteinizing hormone ( LH ) by the anterior pituitary. Decreased levels of FSH inhibit follicular development, preventing an increase in estradiol levels. Progestogen negative feedback and the lack of estrogen positive feedback on LH release prevent a mid-cycle LH surge. Inhibition of follicular development and the absence of a LH surge prevent ovulation. Estrogen was originally included in oral contraceptives for better cycle control ( to stabilize the endometrium and thereby reduce the incidence of breakthrough bleeding ), but was also found to inhibit follicular development and help prevent ovulation. Estrogen negative feedback on the anterior pituitary greatly decreases the release of FSH, which inhibits follicular development and helps prevent ovulation. Another primary mechanism of action of all progestogen - containing contraceptives is inhibition of sperm penetration through the cervix into the upper genital tract ( uterus and fallopian tubes ) by decreasing the amount of and increasing the viscosity of the cervical mucus. The estrogen and progestogen in combined hormonal contraceptives have other effects on the reproductive system, but these have not been shown to contribute to their contraceptive efficacy : Slowing tubal motility and ova transport, which may interfere with fertilization. Endometrial atrophy and alteration of metalloproteinase content, which may impede sperm motility and viability, or theoretically inhibit implantation. Endometrial edema, which may affect implantation. Insufficient evidence exists on whether changes in the endometrium could actually prevent implantation. The primary mechanisms of action are so effective that the possibility of fertilization during combined hormonal contraceptive use is very small. Since pregnancy occurs despite endometrial changes when the primary mechanisms of action fail, endometrial changes are unlikely to play a significant role, if any, in the observed effectiveness of combined hormonal contraceptives. Progestogen - only The mechanism of action of progestogen - only contraceptives depends on the progestogen activity and dose. Low dose progestogen - only contraceptives include traditional progestogen - only pills, the subdermal implant Jadelle and the intrauterine system Mirena. These contraceptives inconsistently inhibit ovulation in ~ 50 % of cycles and rely mainly on their progestogenic effect of thickening the cervical mucus and thereby reducing sperm viability and penetration. Intermediate dose progestogen - only contraceptives, such as the progestogen - only pill Cerazette ( or the subdermal implant Implanon ), allow some follicular development but much more consistently inhibit ovulation in 97 -- 99 % of cycles. The same cervical mucus changes occur as with low dose progestogens. High dose progestogen - only contraceptives, such as the injectables Depo - Provera and Noristerat, completely inhibit follicular development and ovulation. The same cervical mucus changes occur as with very low dose and intermediate dose progestogens. In anovulatory cycles using progestogen - only contraceptives, the endometrium is thin and atrophic. If the endometrium was also thin and atrophic during an ovulatory cycle, this could theoretically interfere with implantation of a blastocyst ( embryo ). Ormeloxifene Ormeloxifene does not affect ovulation. It has been shown to increase the rate of blastocyst development and to increase the speed at which the blastocyst is moved from the fallopian tubes into the uterus. Ormeloxifene also suppresses proliferation and decidualization of the endometrium ( the transformation of the endometrium in preparation for possible implantation of an embryo ). While they are believed to prevent implantation rather than fertilization, exactly how these effects operate to prevent pregnancy is not understood. Frequency of use Pills -- combined and progestogen - only -- are the most common form of hormonal contraception. Worldwide, they account for 12 % of contraceptive use. 21 % of users of reversible contraceptives choose COCPs or POPs. Pills are especially popular in more developed countries, where they account for 25 % of contraceptive use. Injectable hormonal contraceptives are also used by a significant portion -- about 6 % -- of the world 's contraceptive users. Other hormonal contraceptives are less common, accounting for less than 1 % of contraceptive use. History In 1921, Ludwig Haberlandt demonstrated a temporary hormonal contraception in a female rabbit by transplanting ovaries from a second, pregnant, animal. By the 1930s, scientists had isolated and determined the structure of the steroid hormones and found that high doses of androgens, oestrogens or progesterone inhibited ovulation. A number of economic, technological, and social obstacles had to be overcome before the development of the first hormonal contraceptive, the combined oral contraceptive pill ( COCP ). In 1957 Enovid, the first COCP, was approved in the United States for the treatment of menstrual disorders. In 1960, the U.S. Food and Drug Administration approved an application that allowed Enovid to be marketed as a contraceptive. The first progestogen - only contraceptive was introduced in 1969 : Depo - Provera, a high - dose progestin injection. Over the next decade and a half, other types of progestogen - only contraceptive were developed : a low - dose progestogen only pill ( 1973 ) ; Progestasert, the first hormonal intrauterine device ( 1976 ) ; and Norplant, the first contraceptive implant ( 1983 ). Combined contraceptives have also been made available in a variety of forms. In the 1960s a few combined injectable contraceptives were introduced, notably Injectable Number 1 in China and Deladroxate in Latin America. A third combined injection, Cyclo - Provera, was reformulated in the 1980s by lowering the dose and renamed Cyclofem ( also called Lunelle ). Cyclofem and Mesigyna, another formulation developed in the 1980s, were approved by the World Health Organization in 1993. NuvaRing, a contraceptive vaginal ring, was first marketed in 2002. 2002 also saw the launch of Ortho Evra, the first contraceptive patch. In 1991, ormeloxifene was introduced as a contraceptive in India. While it acts on the hormonal system, this selective estrogen receptor modulator is not a hormone. See also Reproductive Health Supplies Coalition Male hormonal contraception Progestogen - only injectable contraceptive Estradiol - containing oral contraceptive List of progestogens available in the United States List of estrogens available in the United States Footnotes Jump up ^ Susan Scott Ricci ; Terri Kyle ( 2009 ). `` Common Reproductive Issues ''. Contraception. Lippincott Williams & Wilkins. p. 119. Jump up ^ Jones, Rachel K. ( 2011 ). `` Beyond Birth Control : The Overlooked Benefits Of Oral Contraceptive Pills '' ( PDF ). Guttmacher Institute. November. ^ Jump up to : National Prescribing Service ( 11 December 2009 ). `` NPS News 54 : Hormonal contraceptives - tailoring for the individual ''. Retrieved 19 March 2009. Jump up ^ `` Hormonal Contraceptives Offer Benefits Beyond Pregnancy Prevention ''. The American College of Obstetricians and Gynecologists. Retrieved 5 May 2013. Jump up ^ `` Hirsutism and Polycystic Ovary Syndrome '' ( PDF ). American Society for Reproductive Medicine. Retrieved 5 May 2013. Jump up ^ `` Noncontraceptive Benefits of Birth Control Pills ''. Reproductivefacts.org. The American Society for Reproductive Medicine. Retrieved 5 May 2013. Jump up ^ `` Dysmenorrhea '' ( PDF ). The American College of Obstetricians and Gynecologists. Retrieved 5 May 2013. Jump up ^ `` Menorrhagia ( Heavy Menstrual Bleeding ) ''. The Mayo Clinic. Retrieved 5 May 2013. Jump up ^ `` Hirsutism and Polycystic Ovary Syndrome ( PCOS ) '' ( PDF ). American Society for Reproductive Medicine. Retrieved 5 May 2013. Jump up ^ Sivin I, Campodonico I, Kiriwat O, Holma P, Diaz S, Wan L, Biswas A, Viegas O, el din Abdalla K, Anant MP, Pavez M, Stern J ( 1998 ). `` The performance of levonorgestrel rod and Norplant contraceptive implants : a 5 year randomized study ''. Hum. Reprod. 13 ( 12 ) : 3371 -- 8. PMID 9886517. doi : 10.1093 / humrep / 13.12. 3371. ^ Jump up to : Trussell, James ( 2007 ). `` Contraceptive Efficacy ''. In Hatcher, Robert A. ; et al. Contraceptive Technology ( 19th rev. ed. ). New York : Ardent Media. ISBN 0 - 9664902 - 0 - 7. Jump up ^ Puri V, et al. ( 1988 ). `` Results of multicentric trial of Centchroman ''. In Dhwan B.N., et al. Pharmacology for Health in Asia : Proceedings of Asian Congress of Pharmacology, 15 -- 19 January 1985, New Delhi, India. Ahmedabad : Allied Publishers. CS1 maint : Explicit use of et al. ( link ) Jump up ^ Nityanand S, et al. ( 1990 ). `` Clinical evaluation of Centchroman : a new oral contraceptive ''. In Puri, Chander P., Van Look, Paul F.A. Hormone Antagonists for Fertility Regulation. Bombay : Indian Society for the Study of Reproduction and Fertility. Jump up ^ O'Connor, M.L. ( March -- April 2001 ). `` Contraceptive Use Elevates The Odds of Barrier Method Use for Disease Prevention ''. Family Planning Perspectives. Guttmacher Institute. 33 ( 2 ) : 93. doi : 10.2307 / 2673760. Retrieved 2009 - 08 - 30. Jump up ^ Paladine, Heather ( 2003 ). `` What 's New In Contraception ''. The Female Patient. Retrieved 2009 - 08 - 30. Jump up ^ POP : Kovacs G ( October 1996 ). `` Progestogen - only pills and bleeding disturbances ''. Human Reproduction. 11 ( Supplement 2 ) : 20 -- 3. PMID 8982741. doi : 10.1093 / humrep / 11. suppl_2. 20. IUS : McCarthy L ( 2006 ). `` Levonorgestrel - Releasing Intrauterine System ( Mirena ) for Contraception ''. Am Fam Physician. 73 ( 10 ) : 1799 --. Retrieved 2009 - 09 - 01. Depo - Provera and Jadelle : Hubacher D, Lopez L, Steiner MJ, Dorflinger L ( August 2009 ). `` Menstrual pattern changes from levonorgestrel subdermal implants and DMPA : systematic review and evidence - based comparisons ''. Contraception. 80 ( 2 ) : 113 -- 8. PMID 19631785. doi : 10.1016 / j. contraception. 2009.02. 008. Implanon : Riney S, O'Shea B, Forde A ( January 2009 ). `` Etonogestrel implant as a contraceptive choice ; patient acceptability and adverse effect profile in a general practice setting ''. Irish Medical Journal. 102 ( 1 ) : 24 -- 5. PMID 19284015. Jump up ^ Garceau RJ, Wajszczuk CJ, Kaunitz AM ( December 2000 ). `` Bleeding patterns of women using Lunelle monthly contraceptive injections ( medroxyprogesterone acetate and estradiol cypionate injectable suspension ) compared with those of women using Ortho - Novum 7 / 7 / 7 ( norethindrone / ethinyl estradiol triphasic ) or other oral contraceptives ''. Contraception. 62 ( 6 ) : 289 -- 95. PMID 11239615. doi : 10.1016 / S0010 - 7824 ( 00 ) 00183 - 9. Jump up ^ Truitt ST, Fraser AB, Grimes DA, Gallo MF, Schulz KF ( October 2003 ). `` Hormonal contraception during lactation : systematic review of randomized controlled trials ''. Contraception. 68 ( 4 ) : 233 -- 8. PMID 14572885. doi : 10.1016 / S0010 - 7824 ( 03 ) 00133 - 1. ^ Jump up to : Kelsey JJ ( December 1996 ). `` Hormonal contraception and lactation ''. Journal of Human Lactation. 12 ( 4 ) : 315 -- 8. PMID 9025449. doi : 10.1177 / 089033449601200419. Jump up ^ `` Maximizing the use of the progestin minipill ''. Contraceptive Technology Update. 20 ( 2 ) : 19 -- 21. February 1999. PMID 12294591. Jump up ^ `` Progestin - only Contraceptives ''. Hall Health Primary Care Center. University of Wisconsin - Seattle. 2007 - 02 - 11. Retrieved 2009 - 09 - 01. ^ Jump up to : International Agency for Research on Cancer ( IARC ) ( 1999 ). `` 5. Summary of Data Reported and Evaluation ''. Oral Contraceptives, Combined ( Vol. 72 ed. ). p. 49. ^ Jump up to : `` Combined Estrogen - Progestogen Contraceptives '' ( PDF ). IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. International Agency for Research on Cancer. 91. 2007. Jump up ^ `` Endometrial cancer and oral contraceptives : an individual participant meta - analysis of 27 276 women with endometrial cancer from 36 epidemiological studies ''. Lancet. 16 : 1061 -- 1070. Aug 4, 2015. PMID 26254030. doi : 10.1016 / S1470 - 2045 ( 15 ) 00212 - 0. Jump up ^ IARC Working Group on the Evaluation of Carcinogenic Risks to Humans ( 1999 ). `` Hormonal contraceptives, progestogens only ''. Hormonal contraception and post-menopausal hormonal therapy ; IARC monographs on the evaluation of carcinogenic risks to humans, Volume 72. Lyon : IARC Press. pp. 339 -- 397. ISBN 92 - 832 - 1272 - X. Jump up ^ `` McKinley Health Center, University of Illinois : OrthoEvra Contraceptive Patch ''. Retrieved 2007 - 07 - 13. Jump up ^ `` Blood Clots with Hormonal Contraception ''. Hormones Matter. 27 January 2016. Jump up ^ Stacey, Dawn ( 2009 - 07 - 28 ). `` Noristerat Injection ''. About.com. Retrieved 2009 - 08 - 29. ^ Jump up to : `` Centchroman ''. Reproductive Health Online. 2003. Retrieved 2009 - 08 - 29. ^ Jump up to : Nelson, Anita L. ; Cwiak, Carrie ( 2011 ). `` Combined oral contraceptives ( COCs ) ''. In Hatcher, Robert A. ; Trussell, James ; Nelson, Anita L. ; Cates, Willard Jr. ; Kowal, Deborah ; Policar, Michael S. ( eds. ). Contraceptive technology ( 20th revised ed. ). New York : Ardent Media. pp. 249 -- 341. ISBN 978 - 1 - 59708 - 004 - 0. ISSN 0091 - 9721. OCLC 781956734. CS1 maint : Extra text : editors list ( link ) pp. 257 -- 258 : Mechanism of action COCs prevent fertilization and, therefore, qualify as contraceptives. There is no significant evidence that they work after fertilization. The progestins in all COCs provide most of the contraceptive effect by suppressing ovulation and thickening cervical mucus, although the estrogens also make a small contribution to ovulation suppression. Cycle control is enhanced by the estrogen. Because COCs so effectively suppress ovulation and block ascent of sperm into the upper genital tract, the potential impact on endometrial receptivity to implantation is almost academic. When the two primary mechanisms fail, the fact that pregnancy occurs despite the endometrial changes demonstrates that those endometrial changes do not significantly contribute to the pill 's mechanism of action. ^ Jump up to : Speroff, Leon ; Darney, Philip D. ( 2011 ). `` Oral contraception ''. A clinical guide for contraception ( 5th ed. ). Philadelphia : Lippincott Williams & Wilkins. pp. 19 -- 152. ISBN 978 - 1 - 60831 - 610 - 6. ^ Jump up to : Levin, Ellis R. ; Hammes, Stephen R. ( 2011 ). `` Estrogens and progestins ''. In Brunton, Laurence L. ; Chabner, Bruce A. ; Knollmann, Björn C. Goodman & Gilman 's pharmacological basis of therapeutics ( 12th ed. ). New York : McGraw - Hill Medical. pp. 1163 -- 1194. ISBN 978 - 0 - 07 - 162442 - 8. ^ Jump up to : Glasier, Anna ( 2010 ). `` Contraception ''. In Jameson, J. Larry ; De Groot, Leslie J. Endocrinology ( 6th ed. ). Philadelphia : Saunders Elsevier. pp. 2417 -- 2427. ISBN 978 - 1 - 4160 - 5583 - 9. ^ Jump up to : `` Family Planning Worldwide : 2008 Data Sheet '' ( PDF ). Population Reference Bureau. 2008. Retrieved 2008 - 06 - 27. Data from surveys 1997 -- 2007. ^ Jump up to : Chandra, A ; Martinez GM ; Mosher WD ; Abma JC ; Jones J. ( 2005 ). `` Fertility, Family Planning, and Reproductive Health of U.S. Women : Data From the 2002 National Survey of Family Growth '' ( PDF ). Vital and Health Statistics. National Center for Health Statistics. 23 ( 25 ). Retrieved 2007 - 05 - 20. See Table 60. Jump up ^ Müller - Jahncke WD ( Aug 1988 ). `` Ludwig Haberlandt ( 1885 - 1932 ) and the development of hormonal contraception ''. Z Gesamte Inn Med ( in German ). GERMANY, EAST. 43 ( 15 ) : 420 -- 2. ISSN 0044 - 2542. PMID 3051743. Jump up ^ Goldzieher JW ( 1982 ). `` Estrogens in oral contraceptives : historical perspective ''. Johns Hopkins Med J. 150 ( 5 ) : 165 -- 9. PMID 7043034. Jump up ^ Perone N ( 1993 ). `` The history of steroidal contraceptive development : the progestins ''. Perspect Biol Med. 36 ( 3 ) : 347 -- 62. PMID 8506121. doi : 10.1353 / pbm. 1993.0054. Jump up ^ Junod SW, Marks L ( 2002 ). `` Women 's trials : the approval of the first oral contraceptive pill in the United States and Great Britain '' ( PDF ). J Hist Med Allied Sci. 57 ( 2 ) : 117 -- 60. PMID 11995593. doi : 10.1093 / jhmas / 57.2. 117. Jump up ^ Leary, Warren E. ( 1992 - 10 - 30 ). `` U.S. Approves Injectable Drug As Birth Control ''. The New York Times. p. A. 1. PMID 11646958. Jump up ^ McFadden, Suzanne ( 2009 - 06 - 15 ). `` Golden anniversary of a revolution ''. The New Zealand Herald. Retrieved 2009 - 08 - 29. Jump up ^ `` IUDs -- An Update ''. Population Information Program, the Johns Hopkins School of Public Health. XXIII ( 5 ). December 1995. chapter = ignored ( help ) Jump up ^ Chin, Mona ( 1992 ). `` The Chronological Important Events in the Development of Norplant ''. Norplant. Retrieved 2009 - 08 - 29., possibly taken from Dorflinger, LJ ( 1991 - 08 - 02 ). `` Explanation of assumptions made for Norplant projections ''. Unpublished. Retrieved 2009 - 08 - 29. Jump up ^ `` Research and regulatory approval ( of injectable contraceptives ) ''. Population Reports. AccessMyLibrary. 1995 - 08 - 01. Retrieved 2009 - 08 - 29. Jump up ^ `` World Health Agency Endorsing 2 New Injectable Contraceptives ''. The New York Times. 1993 - 06 - 06. p. Section 1, p. 20. Retrieved 2009 - 08 - 29. Jump up ^ Organon ( July 16, 2002 ). `` NuvaRing world 's first vaginal birth control ring, first launch now in the US '' ( PDF ). Archived from the original ( PDF ) on 2005 - 10 - 27. Retrieved 2009 - 08 - 29. Jump up ^ Associated Press ( 2001 - 11 - 11 ). `` FDA Approves Contraceptive Patch ''. Wired.com. Retrieved 2009 - 08 - 29. Jump up ^ Singh MM ( July 2001 ). `` Centchroman, a selective estrogen receptor modulator, as a contraceptive and for the management of hormone - related clinical disorders ''. Medical Research Reviews. 21 ( 4 ) : 302 -- 47. PMID 11410933. doi : 10.1002 / med. 1011. Birth control methods ( G02B, G03A ) Comparison Comparison of birth control methods Long - acting reversible contraception Behavioral Avoiding vaginal intercourse : Abstinence Anal sex Masturbation Non-penetrative sex Oral sex Including vaginal intercourse : Breastfeeding infertility ( LAM ) Calendar - based methods ( rhythm, etc. ) Fertility awareness ( Billings ovulation method Creighton Model, etc. ) Withdrawal Barrier and / or spermicidal Cervical cap Condom Contraceptive sponge Diaphragm Female condom Spermicide Hormonal ( formulations ) Combined Contraceptive patch Extended cycle Injectable NuvaRing Oral / ' the pill ' Progestogen - only LARC ( Depo - Provera Implanon / Nexplanon Norplant / Jadelle ) Progestogen - only pill Progesterone vaginal ring Anti-estrogen Ormeloxifene ( Centchroman ) Post-intercourse Emergency contraception ( pills or copper IUD ) ( Ulipristal acetate Yuzpe regimen ) Intrauterine device IUD with copper Paragard IUD with progestogen ( Mirena ) Abortion Medical ( RU - 486 / abortion pill ) Surgical Sterilization Female : Essure Tubal ligation Male : Vasectomy Experimental Reversible inhibition of sperm under guidance ( Vasalgel ) Hormonal contraception ( G02B, G03A ) Androgens Male - only : Dimethandrolone Testosterone buciclate Testosterone undecanoate Trestolone Estrogens Diethylstilbestrol Estradiol Estradiol benzoate Estradiol cypionate Estradiol enanthate Estradiol valerate Ethinylestradiol Mestranol Ormeloxifene Progestogens First generation ( estranes ) Ethisterone Etynodiol diacetate Lynestrenol Norethisterone ( norethindrone ) Norethisterone acetate Norethisterone enanthate Noretynodrel Quingestanol Second generation Estranes : Norethisterone enanthate Norgestrienone Gonanes : Levonorgestrel Norelgestromin Norgestrel Third generation ( gonanes ) Desogestrel Etonogestrel Gestodene Norgestimate Fourth generation Estranes : Dienogest Norpregnanes : Demegestone Nomegestrol acetate Promegestone Trimegestone Spironolactone derivatives : Drospirenone Pregnanes Chlormadinone acetate Medrogestone Medroxyprogesterone acetate Megestrol acetate Miscellaneous Mifepristone Ulipristal acetate Algestone acetophenide Dydrogesterone Gestrinone Progesterone Proligestone Retrieved from `` https://en.wikipedia.org/w/index.php?title=Hormonal_contraception&oldid=801717519 '' Categories : Hepatotoxins Hormonal contraception Sex and drugs Human female endocrine system Hidden categories : CS1 maint : Explicit use of et al. 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Question: where do the hormones in the pill come from
Answer: steroid