Editing Levonorgestrel (section)

{{Short description|Hormonal medication used for birth control}}
{{Distinguish|text= [[Medication abortion]]}}
{{Use dmy dates|date=February 2025}}
{{cs1 config |name-list-style=vanc |display-authors=6}}
{{Infobox drug
| Watchedfields = changed
| verifiedrevid = 462091161
| image = Levonorgestrel.svg
| image_class = skin-invert-image
| alt = 
| width = 225
| image2 = Levonorgestrel molecule ball.png
| alt2 = 
| width2 = 235

<!--Clinical data-->
| tradename = Plan B, Plan B One-Step, others
| Drugs.com = {{drugs.com|monograph|progestins-etonogestrel-levonorgestrel-norethindrone}}
| MedlinePlus = a610021
| pregnancy_AU = B3
| pregnancy_AU_comment = <ref name="Drugs.com pregnancy">{{cite web | title=Levonorgestrel Use During Pregnancy | website=Drugs.com | date=23 March 2020 | url=https://www.drugs.com/pregnancy/levonorgestrel.html | access-date=29 June 2020 | archive-date=2 July 2020 | archive-url=https://web.archive.org/web/20200702123750/https://www.drugs.com/pregnancy/levonorgestrel.html | url-status=live }}</ref>
| pregnancy_category = Contraindicated<ref name="Drugs.com pregnancy" />
| routes_of_administration = [[Oral administration|By mouth]], [[transdermal patch]], [[intrauterine device]], [[subcutaneous implant]]
| class = [[Progestogen (medication)]]; [[Progestin]]
| ATC_prefix = G03
| ATC_suffix = AC03
| ATC_supplemental = {{ATC|G03|AD01}}

<!-- Legal status -->
| legal_AU          = <!-- S2, S3, S4, S5, S6, S7, S8, S9 or Unscheduled -->
| legal_AU_comment  = 
| legal_BR          = <!-- OTC, A1, A2, A3, B1, B2, C1, C2, C3, C4, C5, D1, D2, E, F -->
| legal_BR_comment  = 
| legal_CA          = Rx-only
| legal_CA_comment  = /&nbsp;OTC<ref>{{cite web | title=Norplant Product information | website=[[Health Canada]] | date=24 September 2002 | url=https://health-products.canada.ca/dpd-bdpp/info?lang=eng&code=15779 | access-date=17 February 2025}}</ref><ref>{{cite web | title=Plan B Product information | website=[[Health Canada]] | date=9 May 2018 | url=https://health-products.canada.ca/dpd-bdpp/info?lang=eng&code=65334 | access-date=17 February 2025}}</ref><ref>{{cite web | title=Backup Plan Product information | website=[[Health Canada]] | date=4 May 2019 | url=https://health-products.canada.ca/dpd-bdpp/info?lang=eng&code=91457 | access-date=17 February 2025}}</ref><ref>{{cite web | title=Backup Plan Onestep Product information | website=[[Health Canada]] | date=7 June 2016 | url=https://health-products.canada.ca/dpd-bdpp/info?lang=eng&code=91790 | access-date=17 February 2025}}</ref>
| legal_DE          = <!-- Anlage I, II, III or Unscheduled -->
| legal_DE_comment  = 
| legal_NZ          = <!-- Class A, B, C -->
| legal_NZ_comment  = 
| legal_UK = POM
| legal_UK_comment = <ref>{{cite web | title=Jaydess 13.5 mg intrauterine delivery system - Summary of Product Characteristics (SmPC) | website=(emc) | date=1 July 2022 | url=https://www.medicines.org.uk/emc/product/5297/smpc | access-date=1 July 2022 | archive-date=13 April 2021 | archive-url=https://web.archive.org/web/20210413020051/https://www.medicines.org.uk/emc/product/5297/smpc | url-status=live }}</ref>
| legal_US = Rx-only
| legal_US_comment = /&nbsp;OTC<ref name="Plan B One-Step FDA label">{{cite web | title=Plan B One-Step- levonorgestrel tablet | website=DailyMed | date=21 December 2022 | url=https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=6ce6b40e-14ac-47bd-a648-ddf9e452e559 | access-date=26 December 2022}}</ref>
| legal_EU          = 
| legal_EU_comment  = 
| legal_UN          = <!-- N I, II, III, IV / P I, II, III, IV -->
| legal_UN_comment  = 
| legal_status = Rx/OTC

<!--Pharmacokinetic data-->
| bioavailability = 95% (range 85–100%)<ref name="pmid16112947" /><ref name="pmid8842581" />
| protein_bound = 98% (50% to [[human serum albumin|albumin]], 48% to {{abbrlink|SHBG|sex hormone-binding globulin}})<ref name="pmid16112947" />
| metabolism = [[Liver]] ([[redox|reduction]], [[hydroxylation]], [[conjugation (biochemistry)|conjugation]])<ref name="pmid16112947" /><ref name="ShoupeHaseltine2012" />
| metabolites = • [[5α-Dihydrolevonorgestrel|5α-Dihydro-{{abbr|LNG|levonorgestrel}}]]<ref name="pmid16112947" />
| elimination_half-life = 24–32 hours<ref name="pmid16112947" />
| excretion = [[Urine]]: 20–67%<br />[[Feces]]: 21–34%<ref name="ShoupeHaseltine2012" />

<!--Identifiers-->
| CAS_number_Ref = {{cascite|correct|CAS}}
| CAS_number = 797-63-7
| PubChem = 13109
| IUPHAR_ligand = 2881
| DrugBank_Ref = {{drugbankcite|correct|drugbank}}
| DrugBank = DB00367
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 12560
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 5W7SIA7YZW
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = D00950
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI = 6443
| ChEMBL_Ref = {{ebicite|correct|EBI}}
| ChEMBL = 1389
| synonyms = LNG; LNG-EC; d-Norgestrel; d(–)-Norgestrel; <small>D</small>-Norgestrel; WY-5104; SH-90999; NSC-744007; 18-Methylnorethisterone; 17α-Ethynyl-18-methyl-19-nortestosterone; 17α-Ethynyl-18-methylestr-4-en-17β-ol-3-one; 13β-Ethyl-17α-hydroxy-18,19-dinorpregn-4-en-20-yn-3-one

<!--Chemical data-->
| IUPAC_name = (8''R'',9''S'',10''R'',13''S'',14''S'',17''R'')-13-ethyl-17-ethynyl-17-hydroxy-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[''a'']phenanthren-3-one
| C=21 | H=28 | O=2
<!-- | LogP =3.8 unk param -->
| SMILES = CC[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@]2(C#C)O)CCC4=CC(=O)CC[C@H]34
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C21H28O2/c1-3-20-11-9-17-16-8-6-15(22)13-14(16)5-7-18(17)19(20)10-12-21(20,23)4-2/h2,13,16-19,23H,3,5-12H2,1H3/t16-,17+,18+,19-,20-,21-/m0/s1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = WWYNJERNGUHSAO-XUDSTZEESA-N
| melting_point = 235
| melting_high = 237
}}
<!-- Definition and medical uses -->
'''Levonorgestrel''' is a [[hormonal medication]] used in a number of [[birth control]] methods.<ref name="Plan B One-Step FDA label" /><ref name=AHFS2015>{{cite web|title=Progestins (Etonogestrel, Levonorgestrel, Norethindrone)|url=https://www.drugs.com/monograph/progestins-etonogestrel-levonorgestrel-norethindrone.html|publisher=The American Society of Health-System Pharmacists|access-date=21 August 2015|url-status=live|archive-url=https://web.archive.org/web/20150907223756/http://www.drugs.com/monograph/progestins-etonogestrel-levonorgestrel-norethindrone.html|archive-date=7 September 2015}}</ref> It is combined with an [[estrogen]] to make [[combined oral birth control pill|combination birth control pill]]s.<ref>{{cite book|title=Postgraduate Gynecology.|date=2011|publisher=Jaypee Brothers Medical Pub|isbn=9789350250822|page=159|url=https://books.google.com/books?id=Kd7lNFPipaIC&pg=PT174|url-status=live|archive-url=https://web.archive.org/web/20150926022813/https://books.google.ca/books?id=Kd7lNFPipaIC&pg=PT174|archive-date=26 September 2015}}</ref> As an [[emergency birth control]], sold under the brand names '''Plan B One-Step''' and '''Julie''', among others, it is useful within 72 hours<!-- The reference clearly states 72 hours for Levonorgestrel. Also can be checked on various different medicine websites, including BNF, eMC, NICE guidelines, and various other reputable sources including the reference provided!! --> of unprotected [[sexual intercourse|sex]].<ref name="Plan B One-Step FDA label" /><ref name=AHFS2015/><ref>{{cite web | title = Levonorgestrel 1.5 mg Tablet Emergency Contraceptive: New Drug Application 21998, Supplement 5 | publisher = U.S. Food and Drug Administration | url = https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/021998Orig1s005SumR.pdf| archive-url = https://web.archive.org/web/20221223221227/https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/021998Orig1s005SumR.pdf| url-status = dead| archive-date = 23 December 2022}}</ref> The more time that has passed since sex, the less effective the medication becomes.<ref name=AHFS2015/> Levonorgestrel works by preventing or delaying [[ovulation]] so an egg cannot be released. The dosage used for emergency contraception is ineffective when ovulation has already occurred, and has been found to have no effect on [[Implantation (embryology)|implantation]].<ref>{{Cite journal |last= |first= |date=2022 |title=Plan B One-Step (1.5 mg levonorgestrel) Information |url=https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/plan-b-one-step-15-mg-levonorgestrel-information#:~:text=B%20One-Step.-,FDA%20determined%20the%20current%20science%20supports%20a%20conclusion%20that%20Plan,such%20as%20fertilization%20or%20implantation. |archive-url=https://web.archive.org/web/20221223204800/https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/plan-b-one-step-15-mg-levonorgestrel-information#:~:text=B%20One-Step.-,FDA%20determined%20the%20current%20science%20supports%20a%20conclusion%20that%20Plan,such%20as%20fertilization%20or%20implantation. |url-status=dead |archive-date=23 December 2022 |journal=FDA |language=en}}</ref> It decreases the chances of pregnancy by 57–93%.<ref name="Gem2010">{{cite journal | vauthors = Gemzell-Danielsson K | title = Mechanism of action of emergency contraception | journal = Contraception | volume = 82 | issue = 5 | pages = 404–409 | date = November 2010 | pmid = 20933113 | doi = 10.1016/j.contraception.2010.05.004 }}</ref> In an [[intrauterine device]] (IUD), such as '''Mirena''' among others, it is effective for the long-term prevention of [[pregnancy]].<ref name=AHFS2015/> A [[levonorgestrel-releasing implant]] is also available in some countries.<ref>{{cite book|title=Research on reproductive health at WHO: biennial report 2000-2001|date=2002|publisher=World health organization|location=Geneva|isbn=9789241562089|chapter-url=https://books.google.com/books?id=cvKaqyMOGjUC&pg=PT15|chapter=Chapter 1|url-status=live|archive-url=https://web.archive.org/web/20150926040930/https://books.google.ca/books?id=cvKaqyMOGjUC&pg=PT15|archive-date=26 September 2015}}</ref>

<!-- Side effects and mechanism of action -->
Common [[side effect]]s include [[nausea]], [[breast tenderness]], [[headache]]s, and [[menorrhagia|increased]], [[hypomenorrhea|decreased]], or [[irregular menstrual bleeding]].<ref name=AHFS2015/> When used as an emergency contraceptive, if pregnancy occurs, there is no evidence that its use [[teratogen|harms the fetus]].<ref name=AHFS2015/> It is safe to use during [[breastfeeding]].<ref name=AHFS2015/> Birth control that contains levonorgestrel will not change the risk of [[sexually transmitted infection]]s.<ref name=AHFS2015/> It is a [[progestin]] and has effects similar to those of the hormone [[progesterone]].<ref name=AHFS2015/> It works primarily by preventing [[ovulation]] and closing off the [[cervix]] to prevent the passage of [[sperm]].<ref name=AHFS2015/>

<!-- History, society, and culture -->
Levonorgestrel was patented in 1960 and introduced for medical use together with [[ethinylestradiol]] in 1970.<ref name=Fis2006>{{cite book | vauthors = Fischer J, Ganellin CR |title=Analogue-based Drug Discovery |date=2006 |publisher=John Wiley & Sons |isbn=9783527607495 |page=479 |url=https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA479 |access-date=5 August 2020 |archive-date=28 August 2021 |archive-url=https://web.archive.org/web/20210828143151/https://books.google.com/books?id=FjKfqkaKkAAC&pg=PA479 |url-status=live }}</ref><ref name=Roth2014/> It is on the [[WHO Model List of Essential Medicines|World Health Organization's List of Essential Medicines]].<ref name="WHO21st">{{cite book | vauthors = ((World Health Organization)) | title = World Health Organization model list of essential medicines: 21st list 2019 | year = 2019 | hdl = 10665/325771 | author-link = World Health Organization | publisher = World Health Organization | location = Geneva | id = WHO/MVP/EMP/IAU/2019.06. License: CC BY-NC-SA 3.0 IGO }}</ref> It is available as a [[generic medication]].<ref name=Ric2014>{{cite book| vauthors = Hamilton RJ |title=Tarascon pocket pharmacopoeia : 2014 deluxe lab-pocket edition|date=2014|publisher=Jones & Bartlett Learning|location=Sudbury|isbn=9781284053999|pages=310–312|edition=15th|url=https://books.google.com/books?id=BwqEAgAAQBAJ&pg=PA310|url-status=live|archive-url=https://web.archive.org/web/20150926022049/https://books.google.ca/books?id=BwqEAgAAQBAJ&pg=PA310|archive-date=26 September 2015}}</ref> In the United States, levonorgestrel-containing emergency contraceptives are available [[over the counter]] (OTC) for all ages.<ref>{{cite press release |title=FDA approves Plan B One-Step emergency contraceptive for use without a prescription for all women of child-bearing potential|url=https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm358082.htm|access-date=2 February 2016|date=20 June 2013|url-status=dead|archive-url=https://web.archive.org/web/20160114114254/https://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm358082.htm|archive-date=14 January 2016}}</ref> In 2020, it was the 323rd most commonly prescribed medication in the United States, with more than 800{{nbsp}}thousand prescriptions.<ref>{{cite web | title = Levonorgestrel - Drug Usage Statistics | website = ClinCalc | url = https://clincalc.com/DrugStats/Drugs/Levonorgestrel | access-date = 7 October 2022 }}</ref>
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