LEVOSERT

AU:B3Contraindicated G03AC03(WHO)G03AD01(WHO) CA:℞-only/ OTCUK:POM(Prescription only)US:℞-only/ OTCRx/OTC (8R,9S,10R,13S,14S,17R)-13-ethyl-17-ethynyl-17-hydroxy-1,2,6,7,8,9,10,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-3-one 797-63-7Y 13109 2881 DB00367Y 12560Y 5W7SIA7YZW D00950Y CHEBI:6443Y ChEMBL1389Y DTXSID3036496 Interactive image CC[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@]2(C#C)O)CCC4=CC(=O)CC[C@H]34 InChI=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/s1YKey:WWYNJERNGUHSAO-XUDSTZEESA-NY Levonorgestrelis ahormonal medicationused in a number ofbirth controlmethods.It is combined with anestrogento makecombination birth control pills.As anemergency birth control, sold under the brand namesPlan B One-StepandJulie, among others, it is useful within 72 hours of unprotectedsex.The more time that has passed since sex, the less effective the medication becomes.Levonorgestrel works by preventing or delayingovulationso 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 onimplantation.It decreases the chances of pregnancy by 57–93%.In anintrauterine device(IUD), such asMirenaamong others, it is effective for the long-term prevention ofpregnancy.Alevonorgestrel-releasing implantis also available in some countries. Commonside effectsincludenausea,breast tenderness,headaches, andincreased,decreased, orirregular menstrual bleeding.When used as an emergency contraceptive, if pregnancy occurs, there is no evidence that its useharms the fetus.It is safe to use duringbreastfeeding.Birth control that contains levonorgestrel will not change the risk ofsexually transmitted infections.It is aprogestinand has effects similar to those of the hormoneprogesterone.It works primarily by preventingovulationand closing off thecervixto prevent the passage ofsperm. Levonorgestrel was patented in 1960 and introduced for medical use together withethinylestradiolin 1970.It is on theWorld Health Organization's List of Essential Medicines.It is available as ageneric medication.In the United States, levonorgestrel-containing emergency contraceptives are availableover the counter(OTC) for all ages.In 2020, it was the 323rd most commonly prescribed medication in the United States, with more than 800thousand prescriptions.