Chemical Component Summary

FormulaC21 H28 O2
Molecular Weight312.45
Isomeric SMILESCC[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@]2(C#C)O)CCC4=CC(=O)CC[C@H]34

Chemical Details

Formal Charge0
Atom Count51
Chiral Atom Count6
Bond Count54
Aromatic Bond Count0

Drug Info: DrugBank

DrugBank IDDB00367 
  • approved
  • investigational
DescriptionLevonorgestrel (LNG) is a synthetic progestogen similar to [Progesterone] used in contraception and hormone therapy.[A181988,T659] Also known as Plan B, it is used as a single agent in emergency contraception, and as a hormonal contraceptive released from an intrauterine device, commonly referred to as an IUD. Some of these devices are known as Jaydess, Kyleena, and Mirena. A subdermal implant of levonorgestrel that slowly releases the hormone over a long-term period is also available.[L7823] In addition to the above uses, levonorgestrel is used as a component of long-term combination contraceptives.[A181991,L7760,L7778] Globally, levonorgestrel is the most commonly used emergency contraceptive. It was initially granted FDA approval in 1982 and was the first emergency contraceptive containing only progesterone, showing high levels of efficacy and a lack of estrogenic adverse effects when compared to older emergency contraceptive regimens.[A181976,A181994,L7760]
  • 17alpha-Ethynyl-17-hydroxy-18-methylestr-4-en-3-one
  • 13-beta-Ethyl-17alpha-ethynyl-17beta-hydroxygon-4-en-3-one
  • 13-Ethyl-17-alpha-ethynyl-17-beta-hydroxy-4-gonen-3-one
  • 17alpha-Ethynyl-13beta-ethyl-3-oxo-4-estren-17beta-ol
  • 18-Methyl-17-alpha-ethynyl-19-nortestosterone
Brand Names
  • Tyblume
  • Simpesse
  • Jaimiess
  • EContra EZ
  • Nordette
Indication**Emergency contraception** Levonorgestrel, in the single-agent emergency contraceptive form, is indicated for the prevention of pregnancy after the confirmed or suspected failure of contraception methods or following unprotected intercourse. It is distributed by prescription for patients under 17, and over the counter for those above this age.[L7760] This levonorgestrel-only form of contraception is not indicated for regular contraception and must be taken as soon as possible within 72 hours after intercourse.[A181976,L7760] It has shown a lower efficacy when it is used off label within 96 hours.[T659] **Long-term contraception or nonemergency contraception** In addition to the above indication in emergency contraception, levonorgestrel is combined with other contraceptives in contraceptive formulations designed for regular use, for example with ethinyl estradiol.[L7766] It is used in various hormone-releasing intrauterine devices for long-term contraception ranging for a duration of 3-5 years.[L7778,L7781,L7787] Product labeling for Mirena specifically mentions that it is recommended in women who have had at least 1 child.[L7778] A subdermal implant is also available for the prevention of pregnancy for up to 5 years.[L7823] **Hormone therapy and off-label uses** Levonorgestrel is prescribed in combination with estradiol as hormone therapy during menopause to manage vasomotor symptoms and to prevent osteoporosis.[L7805]Off-label, levonorgestrel may be used to treat menorrhagia, endometrial hyperplasia, and endometriosis.[T659]
  • Adrenal Cortex Hormones
  • Combination Contraceptives (with Estrogen and derivatives)
  • Contraceptive Agents, Female
  • Contraceptives, Oral
  • Contraceptives, Oral, Synthetic
  • G03AB03
  • G03AD01
  • G03AC03
  • G03FB09
  • G03AA07
CAS number797-63-7

Drug Targets

NameTarget SequencePharmacological ActionActions
3-oxo-5-alpha-steroid 4-dehydrogenase 1MATATGVAEERLLAALAYLQCAVGCAVFARNRQTNSVYGRHALPSHRLRV...unknowninhibitor
Sex hormone-binding globulinMESRGPLATSRLLLLLLLLLLRHTRQGWALRPVLPTQSAHDPPAVHLSNG...unknowninhibitor,binder
View More
Drug Info/Drug Targets: DrugBank 3.0: a comprehensive resource for 'omics' research on drugs. Knox C, Law V, Jewison T, Liu P, Ly S, Frolkis A, Pon A, Banco K, Mak C, Neveu V, Djoumbou Y, Eisner R, Guo AC, Wishart DS. Nucleic Acids Res. 2011 Jan; 39 (Database issue):D1035-41. | PMID:21059682

Related Resource References

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