What is Levonorgestrel?
'''Levonorgestrel''' is a [[hormonal]] [[medication]] which is used in many [[birth control]] methods.<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=Aug 21, 2015|url-status=live|archive-url=https://web.archive.org/web/20150907223756/http://www.drugs.com/monograph/progestins-etonogestrel-levonorgestrel-norethindrone.html|archive-date=2015-09-07}}</ref> It is combined with an [[estrogen]] to make [[Combined oral contraceptive 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=2015-09-26}}</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>{{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}}</ref> The more time that has passed since sex, the less effective the medication becomes, and it does not work after pregnancy ([[implantation (human embryo)|implantation]]) has happened. Levonorgestrel works by preventing [[ovulation]] or [[fertilization]] from happening.<ref>{{Cite web |title=Now Is the Time to Change Label on Emergency Contr