Levonorgestrel is a progestin found in oral and IUD contraceptives and at higher doses in emergency contraceptives.

Brand Names
Afirmelle 28 Day, Aftera, Alesse, Altavera 28 Day, Amethia 91 Day, Amethyst, Ashlyna 91 Day, Aubra 28 Day, Aviane 28, Ayuna 28 Day Pack, Balcoltra 28 Day, Bionafem, Camrese 91 Day, Camreselo 91 Day, Chateal 28 Day, Climara Pro, Curae, Daysee 91 Day, Delyla 28 Day, Dolishale 28 Day, Econtra, Enpresse 28 Day, Fallback Solo, Falmina 28 Day, Fayosim 91 Day, Her Style, Iclevia 91 Day, Indayo, Introvale 91 Day, Jaimiess 91 Day, Jolessa 91 Day, Joyeaux 28 Day, Julie, Kurvelo, Kyleena, Levonest 28 Day, Levora 0.15/30 28 Day, Liletta, Lo Simpesse, LoJaimiess, Loseasonique, Lutera 28 Day, Marlissa 28 Day, Min-ovral, Mirena, Morning After, My Choice, My Way, Myzilra 28 Day, New Day, Next Choice, Next Choice One Dose, Opcicon One-step, Option 2, Orsythia 28 Day, Plan B, Plan B One-step, Portia 28 Day, Preventeza, Quartette 91 Day Pack, React, Rivelsa 91 Day, Seasonale, Seasonique, Setlakin 91 Day, Simpesse, Skyla, Sronyx 28 Day, Take Action, Triquilar, Trivora 28 Day, Twirla 3 Count Weekly Patch, Tyblume 28 Day, Vienva 28 Day
Generic Name
DrugBank Accession Number

Levonorgestrel (LNG) is a synthetic progestogen similar to Progesterone used in contraception and hormone therapy.7,18 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.29 In addition to the above uses, levonorgestrel is used as a component of long-term combination contraceptives.8,19,21

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.3,9,19

Small Molecule
Approved, Investigational
Average: 312.4458
Monoisotopic: 312.20893014
Chemical Formula
  • (-)-13-Ethyl-17-hydroxy-18,19-dinor-17alpha-pregn-4-en-20-yn-3-one
  • (8R,9S,10R,13S,14S,17R)-13-ethyl-17-ethynyl-17-hydroxy- 1,2,6,7,8,9,10,11,12,13,14,15,16, 17- tetradecahydrocyclopenta[a] phenanthren-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
  • 13-Ethyl-17-alpha-ethynylgon-4-en-17-beta-ol-3-one
  • 17-alpha-Ethinyl-13-beta-ethyl-17-beta-hydroxy-4-estren-3-one
  • 17-alpha-Ethynyl-13-ethyl-19-nortestosterone
  • 17-Ethynyl-18-methyl-19-nortestosterone
  • 17alpha-Ethynyl-13beta-ethyl-3-oxo-4-estren-17beta-ol
  • 17alpha-Ethynyl-17-hydroxy-18-methylestr-4-en-3-one
  • 17alpha-Ethynyl-18-homo-19-nortestosterone
  • 18-Methyl-17-alpha-ethynyl-19-nortestosterone
  • 18-Methylnorethisterone
  • d(-)-Norgestrel
  • Levonorgestrel
  • Lèvonorgestrel
  • Levonorgestrelum
External IDs
  • Wy 5104
  • WY-5104



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.19 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.3,19 It has shown a lower efficacy when it is used off label within 96 hours.18

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.20 It is used in various hormone-releasing intrauterine devices for long-term contraception ranging for a duration of 3-5 years.21,22,23 Product labeling for Mirena specifically mentions that it is recommended in women who have had at least 1 child and can be indicated for the prevention of pregnancy for up to 8 years.21,30 A subdermal implant is also available for the prevention of pregnancy for up to 5 years.29

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.27Off-label, levonorgestrel may be used to treat menorrhagia, endometrial hyperplasia, and endometriosis.18

Reduce drug development failure rates
Build, train, & validate machine-learning models
with evidence-based and structured datasets.
See how
Build, train, & validate predictive machine-learning models with structured datasets.
See how
Associated Conditions
Indication TypeIndicationCombined Product DetailsApproval LevelAge GroupPatient CharacteristicsDose Form
Treatment ofEndometrial hyperplasia••• •••••
Treatment ofEndometriosis••• •••••
Treatment ofHeavy menstrual bleeding•••••••••••••••••••••••• ••••••
Management ofMenorrhagia••• ••••••••••••••••• ••••••
Used in combination to preventOsteoporosis, postmenopausalRegimen in combination with: Estradiol (DB00783)••••••••••••
Associated Therapies
Contraindications & Blackbox Warnings
Prevent Adverse Drug Events Today
Tap into our Clinical API for life-saving information on contraindications & blackbox warnings, population restrictions, harmful risks, & more.
Learn more
Avoid life-threatening adverse drug events with our Clinical API
Learn more

Levonorgestrel prevents pregnancy by interfering with ovulation, fertilization, and implantation. The levonorgestrel-only containing emergency contraceptive tablet is 89% effective if it is used according to prescribing information within 72 hours after intercourse.3,7 The intrauterine and implantable devices releasing levonorgestrel are more than 99% in preventing pregnancy.14,21,22 Levonorgestrel utilized as a component of hormonal therapy helps to prevent endometrial carcinoma associated with unopposed estrogen administration.13

Mechanism of action

Mechanism of action on ovulation

Oral contraceptives containing levonorgestrel suppress gonadotropins, inhibiting ovulation. Specifically, levonorgestrel binds to progesterone and androgen receptors and slows the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. This process results in the suppression of the normal physiological luteinizing hormone (LH) surge that precedes ovulation. It inhibits the rupture of follicles and viable egg release from the ovaries. Levonorgestrel has been proven to be more effective when administered before ovulation.18

Mechanism of action in cervical mucus changes

Similar to other levonorgestrel-containing contraceptives, the intrauterine (IUD) forms of levonorgestrel likely prevent pregnancy by increasing the thickness of cervical mucus, interfering with the movement and survival of sperm, and inducing changes in the endometrium, where a fertilized ovum is usually implanted.21,22 Levonorgestrel is reported to alter the consistency of mucus in the cervix, which interferes with sperm migration into the uterus for fertilization. Levonorgestrel is not effective after implantation has occurred.3 Interestingly, recent evidence has refuted the commonly believed notion that levonorgestrel changes the consistency of cervical mucus when it is taken over a short-term period, as in emergency contraception. Over a long-term period, however, levonorgestrel has been proven to thicken cervical mucus.3 The exact mechanism of action of levonorgestrel is not completely understood and remains a topic of controversy and ongoing investigation.3,19

Effects on implantation*

The effects of levonorgestrel on endometrial receptivity are unclear, and the relevance of this mechanism to the therapeutic efficacy of levonorgestrel is contentious.15,16 Prescribing information for levonorgestrel IUDs state that they exert local morphological changes to the endometrium (e.g. stromal pseudodecidualization, glandular atrophy) that may play a role in their contraceptive activity.21,22

Mechanism of action in hormone therapy

When combined with estrogens for the treatment of menopausal symptoms and prevention of osteoporosis, levonorgestrel serves to lower the carcinogenic risk of unopposed estrogen therapy via the inhibition of endometrial proliferation. Unregulated endometrial proliferation sometimes leads to endometrial cancer after estrogen use.28

AProgesterone receptor
A3-oxo-5-alpha-steroid 4-dehydrogenase 1
AEstrogen receptor alpha
UAndrogen receptor
USex hormone-binding globulin
UGlucocorticoid receptor

Orally administered levonorgestrel is absorbed in the gastrointestinal tract while levonorgestrel administered through an IUD device is absorbed in the endometrium. Levonorgestrel is absorbed immediately in the interstitial fluids when it is inserted as a subdermal implant.29 After insertion of the subdermal implant, the Cmax of levonorgestrel is attained within 2-3 days.29The Cmax following one dose of 0.75 mg of oral levonorgestrel is reached within the hour after administration, according to one reference.3 In a pharmacokinetic study of 1.5 mg of levonorgestrel in women with a normal BMI and those considered to be obese (BMI>30), mean Cmax was found to be 16.2 ng/mL and 10.5 ng/mL respectively. Tmax was found to be 2 hours for those with normal BMI and 2.5 hours for patients with increased BMI.6 The bioavailability of levonorgestrel approaches 100%.25

Mean AUC has been shown to be higher in patients with a normal BMI, measuring at 360.1 h × ng/mL versus a range of 197.28 to 208.1 h × ng/mL in an obese group of patients. Obesity may contribute to decreased efficacy of levonorgestrel in contraception.6

Volume of distribution

One pharmacokinetic study determined a mean steady-state volume of distribution of 1.5 mg of levonorgestrel to be 162.2 L in those with normal BMI and in the range of 404.7 L to 466.4 L in obese patients with a body mass index of at least 30.6 Mean volume of distribution in 16 patients receiving 0.75 mg of levonorgestrel in another pharmacokinetic study was 260 L.4 The Plan B one-step FDA label reports an apparent volume of distribution of 1.8 L/kg.19

Protein binding

The protein binding of levonorgestrel ranges from 97.5-99%, and it is mainly bound to sex hormone-binding globulin (SHBG). Levonorgestrel is also bound to albumin.11,19,22,29 The prescribing information for the implanted levonorgestrel indicates that the concentration of sex hormone-binding globulin (SHBG) is reduced in the span of a few days after levonorgestrel administration, decreasing the levels of the drug.29


After absorption of the oral emergency contraceptive preparation, levonorgestrel is conjugated and forms a large number of sulfate conjugates. In addition, glucuronide conjugates have been identified in the plasma.12 High levels of conjugated and unconjugated 3α, 5β-tetrahydrolevonorgestrel are found in the plasma. The entire metabolic pathway for levonorgestrel has not been studied, however, 16β-hydroxylation is one pathway that has been identified.29 Small quantities of 3α, 5α­ tetrahydrolevonorgestrel and 16βhydroxylevonorgestrel are also formed.19 No active metabolites have been identified.25 The rate of metabolism may be considerably different according to the patient and may explain a wide variation in levonorgestrel clearance.19 Liver CYP3A4 and CYP3A5 hepatic enzymes are reported to be involved in the metabolism of levonorgestrel.17,19

Hover over products below to view reaction partners

Route of elimination

Approximately 45% of an oral levonorgestrel dose and its conjugated or sulfate metabolites are found to be excreted in the urine. Approximately 32% of an orally ingested dose is found excreted in feces, primarily in the form of glucuronide conjugates of levonorgestrel.19


The elimination half-life of a 0.75 mg dose of 1.5 mg of levonorgestrel ranges between 20-60 hours post-administration.3 A pharmacokinetic study of women with a normal BMI and BMI over revealed an elimination half-life of 29.7 h and 41.0-46.4 hours, respectively.6 Another pharmacokinetic study revealed a mean elimination half-life of 24.4 hours after a 0.75 mg dose of levonorgestrel was administered to 16 patients.4


Clearance was found to 4.8 L/h in healthy female volunteers with a normal BMI, and 7.70-8.51 L/h in obese patients after a single 1.5 mg dose.6 After a 0.75 mg dose of levonorgestrel in 16 patients in another pharmacokinetic study, mean clearance was calculated at 7.06 L/h.4 Following levonorgestrel implant removal, the serum concentration falls below 100 pg/mL within the first 96 hours and further falls below the sensitivity of detection within the range of 5 days to 2 weeks.29

Adverse Effects
Improve decision support & research outcomes
With structured adverse effects data, including: blackbox warnings, adverse reactions, warning & precautions, & incidence rates. View sample adverse effects data in our new Data Library!
See the data
Improve decision support & research outcomes with our structured adverse effects data.
See a data sample

The oral LD50 in rats is greater than 5000 mg/kg.24

An overdose of this drug, like other contraceptives, may cause nausea and withdrawal bleeding. Provide symptomatic treatment in the case of a levonorgestrel overdose and contact the local poison control center. There is no specific antidote for a levonorgestrel overdose.19,25,26

Not Available
Pharmacogenomic Effects/ADRs
Not Available


Drug Interactions
This information should not be interpreted without the help of a healthcare provider. If you believe you are experiencing an interaction, contact a healthcare provider immediately. The absence of an interaction does not necessarily mean no interactions exist.
AbametapirThe serum concentration of Levonorgestrel can be increased when it is combined with Abametapir.
AbataceptThe metabolism of Levonorgestrel can be increased when combined with Abatacept.
AbciximabThe risk or severity of adverse effects can be increased when Levonorgestrel is combined with Abciximab.
AcalabrutinibThe metabolism of Levonorgestrel can be decreased when combined with Acalabrutinib.
AcarboseThe therapeutic efficacy of Acarbose can be decreased when used in combination with Levonorgestrel.
Food Interactions
  • Take at the same time every day.
  • Take with or without food. The effect of food on absorption has not been evaluated.


Drug product information from 10+ global regions
Our datasets provide approved product information including:
dosage, form, labeller, route of administration, and marketing period.
Access now
Access drug product information from over 10 global regions.
Access now
Product Images
International/Other Brands
Jadelle (Bayer) / Levonelle (Bayer) / Medonor (Medopharm) / Microlut (Bayer) / Microluton / Microval (Wyeth) / Neogest (Schering) / Norgeston (Bayer) / Norplant (Bayer) / Postinor (Gedeon Richter)
Brand Name Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
JaydessInsert, extended release13.5 mgIntrauterineBayer2013-10-302018-12-20Canada flag
KyleenaIntrauterine device19.5 mg/1IntrauterineBayer HealthCare Pharmaceuticals Inc.2016-09-19Not applicableUS flag
KyleenaInsert, extended release19.5 mgIntrauterineBayer2017-01-10Not applicableCanada flag
LilettaIntrauterine device52 mg/1IntrauterineActavis Pharma, Inc.2015-02-262020-01-31US flag
LilettaIntrauterine device52 mg/1IntrauterineAllergan, Inc.2016-05-31Not applicableUS flag
Generic Prescription Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
LevonorgestrelTablet1.5 mg/1OralHRA Pharma America, Inc.2020-11-01Not applicableUS flag
LevonorgestrelTablet1.5 mg/1OralNovel Laboratories, Inc.2013-02-15Not applicableUS flag
LevonorgestrelTablet1.5 mg/1OralActavis Pharma Company2012-07-162015-08-31US flag
LevonorgestrelTablet1.5 mg/1OralPharmacist Pharmaceutical, LLC2013-06-11Not applicableUS flag
LevonorgestrelTablet1.5 mg/1OralNovel Laboratories, Inc.2013-02-22Not applicableUS flag
Over the Counter Products
NameDosageStrengthRouteLabellerMarketing StartMarketing EndRegionImage
After BangerTablet1.5 mg/1OralAurohealth LLC2023-03-23Not applicableUS flag
AfteraTablet1.5 mg/1OralTeva Women's Health, Inc.2014-10-202020-05-31US flag
AfteraTablet1.5 mg/1OralFoundation Consumer Healthcare LLC2018-05-10Not applicableUS flag
AfterPillTablet1.5 mg/1OralSyzygy Healthcare Solutions, LLC2013-02-152017-09-01US flag
AfterPillTablet1.5 mg/1OralSyzygy Healthcare Solutions, Llc Po Box 588, Westport, Ct 068802017-09-14Not applicableUS flag
Mixture Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
ACTIVA 21Levonorgestrel (150 mcg) + Ethinylestradiol (30 mcg)Tablet, coatedOralFAES FARMA COLOMBIA S.A.S.2008-04-10Not applicableColombia flag
ACTIVA 21 SUAVE®Levonorgestrel (100 mcg) + Ethinylestradiol (20 mcg)Tablet, coatedOralFAES FARMA COLOMBIA S.A.S.2014-05-23Not applicableColombia flag
AfirmelleLevonorgestrel (0.1 mg/1) + Ethinylestradiol (0.02 mg/1)Kit; TabletOralAurobindo Pharma Limited2016-11-14Not applicableUS flag
Alesse 21Levonorgestrel (100 mcg) + Ethinylestradiol (20 mcg)TabletOralPfizer Canada Ulc1998-01-07Not applicableCanada flag
Alesse 28Levonorgestrel (100 mcg) + Ethinylestradiol (20 mcg)TabletOralPfizer Canada Ulc1998-01-07Not applicableCanada flag
Unapproved/Other Products
NameIngredientsDosageRouteLabellerMarketing StartMarketing EndRegionImage
FalessaLevonorgestrel (0.1 mg/1) + Ethinylestradiol (0.02 mg/1) + Folic acid (1 mg/1)KitOralAvion Pharmaceuticals, Llc2014-02-17Not applicableUS flag
Minivlar 30Levonorgestrel (0.15 mg/1) + Ethinylestradiol (0.03 mg/1)TabletOralOASIS TRADING2018-11-21Not applicableUS flag


ATC Codes
G03AB03 — Levonorgestrel and ethinylestradiolG03AD01 — LevonorgestrelG03AC03 — LevonorgestrelG03FB09 — Levonorgestrel and estrogenG03AA07 — Levonorgestrel and ethinylestradiolG03FA11 — Levonorgestrel and estrogen
Drug Categories
Chemical TaxonomyProvided by Classyfire
This compound belongs to the class of organic compounds known as estrogens and derivatives. These are steroids with a structure containing a 3-hydroxylated estrane.
Organic compounds
Super Class
Lipids and lipid-like molecules
Steroids and steroid derivatives
Sub Class
Estrane steroids
Direct Parent
Estrogens and derivatives
Alternative Parents
3-oxo delta-4-steroids / 17-hydroxysteroids / Delta-4-steroids / Cyclohexenones / Ynones / Tertiary alcohols / Cyclic alcohols and derivatives / Acetylides / Organic oxides / Hydrocarbon derivatives
17-hydroxysteroid / 3-oxo-delta-4-steroid / 3-oxosteroid / Acetylide / Alcohol / Aliphatic homopolycyclic compound / Carbonyl group / Cyclic alcohol / Cyclic ketone / Cyclohexenone
Molecular Framework
Aliphatic homopolycyclic compounds
External Descriptors
terminal acetylenic compound, 3-oxo Delta(4)-steroid, 17beta-hydroxy steroid (CHEBI:6443) / Pregnane and derivatives [Fig], C21 steroids (gluco/mineralocorticoids, progestogens) and derivatives (C08153) / C21 steroids (gluco/mineralocorticoids, progestogins) and derivatives (LMST02030119)
Affected organisms
  • Humans and other mammals

Chemical Identifiers

CAS number
InChI Key


Synthesis Reference

Yu-Sheng Chang, Shu-Ping Chen, "Levonorgestrel Crystallization." U.S. Patent US20090069584, issued March 12, 2009.

General References
  1. Edgren RA, Stanczyk FZ: Nomenclature of the gonane progestins. Contraception. 1999 Dec;60(6):313. [Article]
  2. Sitruk-Ware R: New progestagens for contraceptive use. Hum Reprod Update. 2006 Mar-Apr;12(2):169-78. Epub 2005 Nov 16. [Article]
  3. Kahlenborn C, Peck R, Severs WB: Mechanism of action of levonorgestrel emergency contraception. Linacre Q. 2015 Feb;82(1):18-33. doi: 10.1179/2050854914Y.0000000026. [Article]
  4. Kook K, Gabelnick H, Duncan G: Pharmacokinetics of levonorgestrel 0.75 mg tablets. Contraception. 2002 Jul;66(1):73-6. [Article]
  5. Sambol NC, Harper CC, Kim L, Liu CY, Darney P, Raine TR: Pharmacokinetics of single-dose levonorgestrel in adolescents. Contraception. 2006 Aug;74(2):104-9. doi: 10.1016/j.contraception.2006.01.011. Epub 2006 Jun 16. [Article]
  6. Natavio M, Stanczyk FZ, Molins EAG, Nelson A, Jusko WJ: Pharmacokinetics of the 1.5 mg levonorgestrel emergency contraceptive in women with normal, obese and extremely obese body mass index. Contraception. 2019 May;99(5):306-311. doi: 10.1016/j.contraception.2019.01.003. Epub 2019 Jan 28. [Article]
  7. Shohel M, Rahman MM, Zaman A, Uddin MM, Al-Amin MM, Reza HM: A systematic review of effectiveness and safety of different regimens of levonorgestrel oral tablets for emergency contraception. BMC Womens Health. 2014 Apr 4;14:54. doi: 10.1186/1472-6874-14-54. [Article]
  8. Polis CB, Phillips SJ, Hillier SL, Achilles SL: Levonorgestrel in contraceptives and multipurpose prevention technologies: does this progestin increase HIV risk or interact with antiretrovirals? AIDS. 2016 Nov 13;30(17):2571-2576. doi: 10.1097/QAD.0000000000001229. [Article]
  9. Raymond EG, Coeytaux F, Gemzell-Danielsson K, Moore K, Trussell J, Winikoff B: Embracing post-fertilisation methods of family planning: a call to action. J Fam Plann Reprod Health Care. 2013 Oct;39(4):244-6. doi: 10.1136/jfprhc-2013-100702. [Article]
  10. Beatty MN, Blumenthal PD: The levonorgestrel-releasing intrauterine system: Safety, efficacy, and patient acceptability. Ther Clin Risk Manag. 2009 Jun;5(3):561-74. doi: 10.2147/tcrm.s5624. Epub 2009 Aug 3. [Article]
  11. Juchem M, Pollow K: Binding of oral contraceptive progestogens to serum proteins and cytoplasmic receptor. Am J Obstet Gynecol. 1990 Dec;163(6 Pt 2):2171-83. doi: 10.1016/0002-9378(90)90559-p. [Article]
  12. Stanczyk FZ, Roy S: Metabolism of levonorgestrel, norethindrone, and structurally related contraceptive steroids. Contraception. 1990 Jul;42(1):67-96. [Article]
  13. Brinton LA, Felix AS: Menopausal hormone therapy and risk of endometrial cancer. J Steroid Biochem Mol Biol. 2014 Jul;142:83-9. doi: 10.1016/j.jsbmb.2013.05.001. Epub 2013 May 13. [Article]
  14. Townsend S: Norplant: safe and highly effective. Netw Res Triangle Park N C. 1990 Dec;11(4):6-8. [Article]
  15. Mozzanega B, Nardelli GB: UPA and LNG in emergency contraception: the information by EMA and the scientific evidences indicate a prevalent anti-implantation effect. Eur J Contracept Reprod Health Care. 2019 Jan 18:1-7. doi: 10.1080/13625187.2018.1555662. [Article]
  16. Gemzell-Danielsson K, Berger C, Lalitkumar PG: Mechanisms of action of oral emergency contraception. Gynecol Endocrinol. 2014 Oct;30(10):685-7. doi: 10.3109/09513590.2014.950648. Epub 2014 Aug 12. [Article]
  17. Moreno I, Quinones L, Catalan J, Miranda C, Roco A, Sasso J, Tamayo E, Caceres D, Tchernitchin AN, Gaete L, Saavedra I: [Influence of CYP3A4/5 polymorphisms in the pharmacokinetics of levonorgestrel: a pilot study]. Biomedica. 2012 Oct-Dec;32(4):570-7. doi: 10.1590/S0120-41572012000400012. [Article]
  18. Christina Vrettakos; Tushar Bajaj (2019). Levonorgestrel. Stat Pearls NIH.
  19. Levonorgestrel FDA label [Link]
  20. Alesse 28 FDA label [Link]
  21. FDA Approved Drug Products: Mirena (levonorgestrel) intrauterine system [Link]
  22. Kyleena IUD FDA label [Link]
  23. Jaydess monograph [Link]
  24. Levonorgestrel MSDS [Link]
  25. Medicines UK, levonorgestrel [Link]
  26. Birth control pill overdose, Medline [Link]
  27. Climara pro FDA label [Link]
  28. Cleveland clinic: hormone therapy [Link]
  29. Norplant FDA label [Link]
  30. FDA Approved Drug Products: Mirena (levonorgestrel) intrauterine system 2022 [Link]
  31. FDA Approved Drug Products: LOSEASONIQUE® (levonorgestrel and ethinyl estradiol tablets; and ethinyl estradiol tablets) for oral use [Link]
  32. FDA Approved Drug Products: LILETTA (levonorgestrel-releasing intrauterine system [Link]
Human Metabolome Database
KEGG Compound
PubChem Compound
PubChem Substance
Therapeutic Targets Database
Guide to Pharmacology
GtP Drug Page
PDBe Ligand
RxList Drug Page
Drugs.com Drug Page
PDRhealth Drug Page
PDB Entries
1lhv / 3d90
Download (19.7 KB)

Clinical Trials

Clinical Trials
Clinical Trial & Rare Diseases Add-on Data Package
Explore 4,000+ rare diseases, orphan drugs & condition pairs, clinical trial why stopped data, & more. Preview package
PhaseStatusPurposeConditionsCountStart DateWhy Stopped100+ additional columns
Not AvailableNot Yet RecruitingTreatmentEndometrioid Carcinoma / Fertility Preservation1somestatusstop reasonjust information to hide
4Active Not RecruitingBasic ScienceArts / Contraception / Human Immunodeficiency Virus (HIV) Infections1somestatusstop reasonjust information to hide
4CompletedNot AvailableContraception / Epilepsy1somestatusstop reasonjust information to hide
4CompletedNot AvailableEndometriosis1somestatusstop reasonjust information to hide
4CompletedBasic ScienceContraception3somestatusstop reasonjust information to hide


  • Wyeth pharmaceuticals inc
  • Population council
  • Population council center for biomedical research
  • Bayer healthcare pharmaceuticals inc
  • Watson laboratories inc
  • Duramed pharmaceuticals inc
  • 3M Health Care
  • A-S Medication Solutions LLC
  • Barr Pharmaceuticals
  • Bayer Healthcare
  • Berlex Labs
  • Cardinal Health
  • Chemical Works Of Gedeon Richter Ltd.
  • Dept Health Central Pharmacy
  • Dispensing Solutions
  • Diversified Healthcare Services Inc.
  • Duramed
  • Gynetics Inc.
  • Patheon Inc.
  • PCAS Finland Oy
  • PD-Rx Pharmaceuticals Inc.
  • Pharmaceutical Utilization Management Program VA Inc.
  • Physician Partners Ltd.
  • Physicians Total Care Inc.
  • Professional Co.
  • Rebel Distributors Corp.
  • Redpharm Drug
  • Schering Corp.
  • SCS Pharmaceuticals
  • Teva Pharmaceutical Industries Ltd.
  • Watson Pharmaceuticals
  • Womens Capital Corp.
  • Wyeth Pharmaceuticals
Dosage Forms
InsertVaginal20 mcg/24hr
Intrauterine deviceIntrauterine52 mg
TabletOral0.750 mg
Kit; patchTransdermal
TabletOral1.500 mg
TabletOral1.5 g
Patch, extended releaseTransdermal
Tablet, sugar coatedOral0.03 mg
ImplantParenteral75.00 mg
ImplantSubcutaneous75 mg
Insert, extended releaseIntrauterine13.5 mg
Intrauterine deviceIntrauterine13.5 MG
Intrauterine deviceIntrauterine1350000 mg
TabletOral0.150 mg
Insert, extended releaseIntrauterine19.5 mg
Intrauterine deviceIntrauterine19.5 mg/1
Intrauterine deviceIntrauterine19.5 MG
Tablet, coatedOral0.1 MG/0.02MG
Tablet, film coatedOral0.02 MG
Tablet, coatedOral0.03 mg
ImplantSubcutaneous75.00 mg
Kit; tabletOral
Tablet, coatedOral0.75 mg
Tablet, coatedOral0.02 MG
Tablet, film coatedOral
PowderIntrauterine52.00 mg
Tablet, sugar coatedOral0.03 mg
Tablet, coatedOral
Tablet, coatedOral
ImplantIntrauterine52 MG
Insert, extended releaseIntrauterine52 mg
Intrauterine deviceIntrauterine20 mcg/24hrs
Intrauterine deviceIntrauterine52 mg/1
Intrauterine deviceIntrauterine5200000 mg
PowderIntrauterine19.500 mg
Intrauterine deviceIntrauterine
Intrauterine deviceIntrauterine20 Mikrogramm/24stunde
Drug delivery systemIntrauterine52 mg
Intrauterine deviceIntrauterine20 mcg/24hr
Tablet, delayed releaseOral
TabletOral1.5 mg/1.5mg
TabletOral0.75 mg/1
TabletOral0750 MG
TabletOral750 mcg
Intrauterine deviceIntrauterine36 mg
ImplantSubcutaneous36 mg / imp
Tablet, film coated; tablet, sugar coatedOral
TabletOral1.5 mg/1
TabletOral0.03 mg
TabletOral150000 mg
Kit; tablet, film coatedOral
Kit; tablet, coatedOral
Intrauterine deviceIntrauterine13.5 mg/1
ImplantSubcutaneous160 Mg
Tablet, film coatedOral1.5 mg
Capsule, liquid filledOral
Implant75 mg/implant
TabletOral0.75 mg
TabletOral1.5 mg
Tablet, film coated
Tablet, coatedOral1.5 mg
Tablet, film coatedOral0.75 mg
Tablet, sugar coatedOral
Intrauterine deviceIntrauterine52 mg/1piece
Unit descriptionCostUnit
Mirena system843.66USD each
Mirena System 52 mg Insert363.54USD insert
Nordette (28) 28 0.15-30 mg-mcg tablet Disp Pack79.32USD disp
Plan b one-step 1.5 mg tablet40.62USD tablet
Next choice 0.75 mg tablet36.56USD tablet
Levora 0.15/30 (28) 28 0.15-30 mg-mcg tablet Disp Pack32.99USD disp
Trivora (28) 28 tablet Box29.99USD box
Plan b 0.75 mg tablet15.65USD tablet
Nordette-28 tablet2.75USD tablet
Nordette-8 tablet2.39USD tablet
Levlen 28 tablet1.3USD tablet
Tri-levlen 28 tablet1.25USD tablet
Levora-28 tablet1.1USD tablet
Trivora-28 tablet0.98USD tablet
Acidophilus 10 bu/gm granules0.6USD g
DrugBank does not sell nor buy drugs. Pricing information is supplied for informational purposes only.
Patent NumberPediatric ExtensionApprovedExpires (estimated)Region
US6156742No2000-12-052020-12-05US flag
US5785053No1998-07-282015-12-05US flag
US5898032No1999-04-272017-06-23US flag
USRE39861No2007-09-252017-06-23US flag
US7320969No2008-01-222024-01-30US flag
US7615545No2009-11-102023-06-15US flag
US7855190No2010-12-212028-12-05US flag
US7858605No2010-12-282023-06-23US flag
US6500814No2002-12-312018-09-03US flag
US7252839No2007-08-072023-11-13US flag
US8450299No2013-05-282025-10-07US flag
US8415332No2013-04-092029-03-11US flag
US9668912No2017-06-062031-04-01US flag
US9615965No2017-04-112029-09-16US flag
US10028858No2018-07-242034-03-22US flag
US6716814No2004-04-062021-08-16US flag
US9050348No2015-06-092028-07-10US flag
US8221784No2012-07-172021-03-14US flag
US8747888No2014-06-102028-07-10US flag
US8221785No2012-07-172021-03-14US flag
US7384650No2008-06-102021-03-14US flag
US8246978No2012-08-212028-08-26US flag
US8883196No2014-11-112020-11-22US flag
US7045145No2006-05-162021-03-14US flag
US10561524No2020-02-182029-09-16US flag
US10987244No2021-04-272031-04-01US flag
US11090186No2021-08-172033-10-24US flag
US7838042No2010-11-232027-06-01US flag
US11571328No2020-09-072040-09-07US flag
US11628088No2007-02-072027-02-07US flag
US11850182No2009-09-142029-09-14US flag


Experimental Properties
melting point (°C)232-239https://www.fishersci.com/store/msds?partNumber=AC461100010&productDescription=LEVONORGESTREL%2C+98%25+1GR&vendorId=VN00032119&countryCode=US&language=en
boiling point (°C)459.1https://www.lookchem.com/Levonorgestrel/
water solubility2.05 mg/Lhttp://www.t3db.ca/toxins/T3D4749
Predicted Properties
Water Solubility0.00583 mg/mLALOGPS
pKa (Strongest Acidic)17.91Chemaxon
pKa (Strongest Basic)-1.5Chemaxon
Physiological Charge0Chemaxon
Hydrogen Acceptor Count2Chemaxon
Hydrogen Donor Count1Chemaxon
Polar Surface Area37.3 Å2Chemaxon
Rotatable Bond Count1Chemaxon
Refractivity92.03 m3·mol-1Chemaxon
Polarizability36.75 Å3Chemaxon
Number of Rings4Chemaxon
Rule of FiveYesChemaxon
Ghose FilterYesChemaxon
Veber's RuleYesChemaxon
MDDR-like RuleNoChemaxon
Predicted ADMET Features
Human Intestinal Absorption+1.0
Blood Brain Barrier+0.9453
Caco-2 permeable+0.8094
P-glycoprotein substrateSubstrate0.6648
P-glycoprotein inhibitor IInhibitor0.5
P-glycoprotein inhibitor IINon-inhibitor0.8382
Renal organic cation transporterNon-inhibitor0.7697
CYP450 2C9 substrateNon-substrate0.7904
CYP450 2D6 substrateNon-substrate0.9165
CYP450 3A4 substrateSubstrate0.7239
CYP450 1A2 substrateNon-inhibitor0.9045
CYP450 2C9 inhibitorNon-inhibitor0.907
CYP450 2D6 inhibitorNon-inhibitor0.9232
CYP450 2C19 inhibitorInhibitor0.8994
CYP450 3A4 inhibitorNon-inhibitor0.7772
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.516
Ames testNon AMES toxic0.9132
BiodegradationNot ready biodegradable0.9814
Rat acute toxicity1.8264 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.8205
hERG inhibition (predictor II)Non-inhibitor0.7408
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397)


Mass Spec (NIST)
Not Available
SpectrumSpectrum TypeSplash Key
Predicted GC-MS Spectrum - GC-MSPredicted GC-MSsplash10-001i-0490000000-497c4ebd506c0b9c8ec3
LC-MS/MS Spectrum - LC-ESI-qTof , PositiveLC-MS/MSsplash10-066r-0931000000-4a863e895a5edd6cebeb
MS/MS Spectrum - , positiveLC-MS/MSsplash10-03di-0439000000-bcbc7c657a115dced40a
MS/MS Spectrum - , positiveLC-MS/MSsplash10-0a5a-3920000000-edbd3785e7d20d9e81be
MS/MS Spectrum - , positiveLC-MS/MSsplash10-0a4i-2920000000-a08b14b6d762cf4c42b1
Predicted MS/MS Spectrum - 10V, Positive (Annotated)Predicted LC-MS/MSsplash10-03di-0029000000-8f99dd0dd3dd66c78670
Predicted MS/MS Spectrum - 10V, Negative (Annotated)Predicted LC-MS/MSsplash10-03di-0009000000-5e62a92c7270fa13358a
Predicted MS/MS Spectrum - 20V, Positive (Annotated)Predicted LC-MS/MSsplash10-03xv-0961000000-80c5f72d918cca639af5
Predicted MS/MS Spectrum - 20V, Negative (Annotated)Predicted LC-MS/MSsplash10-03di-0009000000-31678a3a3ab82bb75e5e
Predicted MS/MS Spectrum - 40V, Negative (Annotated)Predicted LC-MS/MSsplash10-01q9-0192000000-a7f63433e2d08a212992
Predicted MS/MS Spectrum - 40V, Positive (Annotated)Predicted LC-MS/MSsplash10-046r-0900000000-3cbc1f5e11c4af0212be
13C NMR Spectrum1D NMRNot Applicable
Predicted 1H NMR Spectrum1D NMRNot Applicable
Predicted 13C NMR Spectrum1D NMRNot Applicable
Chromatographic Properties
Collision Cross Sections (CCS)
AdductCCS Value (Å2)Source typeSource
DarkChem Lite v0.1.0
DarkChem Lite v0.1.0
DarkChem Lite v0.1.0
DeepCCS 1.0 (2019)
DarkChem Lite v0.1.0
DarkChem Lite v0.1.0
DarkChem Lite v0.1.0
DeepCCS 1.0 (2019)
DarkChem Lite v0.1.0
DarkChem Lite v0.1.0
DarkChem Lite v0.1.0
DeepCCS 1.0 (2019)


Build, predict & validate machine-learning models
Use our structured and evidence-based datasets to unlock new
insights and accelerate drug research.
Learn more
Use our structured and evidence-based datasets to unlock new insights and accelerate drug research.
Learn more
Pharmacological action
General Function
Zinc ion binding
Specific Function
The steroid hormones and their receptors are involved in the regulation of eukaryotic gene expression and affect cellular proliferation and differentiation in target tissues. Progesterone receptor ...
Gene Name
Uniprot ID
Uniprot Name
Progesterone receptor
Molecular Weight
98979.96 Da
  1. Maruo T, Ohara N, Matsuo H, Xu Q, Chen W, Sitruk-Ware R, Johansson ED: Effects of levonorgestrel-releasing IUS and progesterone receptor modulator PRM CDB-2914 on uterine leiomyomas. Contraception. 2007 Jun;75(6 Suppl):S99-103. Epub 2007 Mar 21. [Article]
  2. Hompes PG, Mijatovic V: Endometriosis: the way forward. Gynecol Endocrinol. 2007 Jan;23(1):5-12. [Article]
  3. Creinin MD, Schlaff W, Archer DF, Wan L, Frezieres R, Thomas M, Rosenberg M, Higgins J: Progesterone receptor modulator for emergency contraception: a randomized controlled trial. Obstet Gynecol. 2006 Nov;108(5):1089-97. [Article]
  4. Bray JD, Jelinsky S, Ghatge R, Bray JA, Tunkey C, Saraf K, Jacobsen BM, Richer JK, Brown EL, Winneker RC, Horwitz KB, Lyttle CR: Quantitative analysis of gene regulation by seven clinically relevant progestins suggests a highly similar mechanism of action through progesterone receptors in T47D breast cancer cells. J Steroid Biochem Mol Biol. 2005 Dec;97(4):328-41. Epub 2005 Sep 12. [Article]
  5. Christina Vrettakos; Tushar Bajaj (2019). Levonorgestrel. Stat Pearls NIH.
Pharmacological action
Curator comments
This target action is based on data from in vitro studies.
General Function
Electron carrier activity
Specific Function
Converts testosterone into 5-alpha-dihydrotestosterone and progesterone or corticosterone into their corresponding 5-alpha-3-oxosteroids. It plays a central role in sexual differentiation and andro...
Gene Name
Uniprot ID
Uniprot Name
3-oxo-5-alpha-steroid 4-dehydrogenase 1
Molecular Weight
29458.18 Da
  1. Rabe T, Kowald A, Ortmann J, Rehberger-Schneider S: Inhibition of skin 5 alpha-reductase by oral contraceptive progestins in vitro. Gynecol Endocrinol. 2000 Aug;14(4):223-30. [Article]
  2. Cassidenti DL, Paulson RJ, Serafini P, Stanczyk FZ, Lobo RA: Effects of sex steroids on skin 5 alpha-reductase activity in vitro. Obstet Gynecol. 1991 Jul;78(1):103-7. [Article]
Pharmacological action
General Function
Zinc ion binding
Specific Function
Nuclear hormone receptor. The steroid hormones and their receptors are involved in the regulation of eukaryotic gene expression and affect cellular proliferation and differentiation in target tissu...
Gene Name
Uniprot ID
Uniprot Name
Estrogen receptor
Molecular Weight
66215.45 Da
  1. Vereide AB, Kaino T, Sager G, Arnes M, Orbo A: Effect of levonorgestrel IUD and oral medroxyprogesterone acetate on glandular and stromal progesterone receptors (PRA and PRB), and estrogen receptors (ER-alpha and ER-beta) in human endometrial hyperplasia. Gynecol Oncol. 2006 May;101(2):214-23. Epub 2005 Dec 1. [Article]
  2. Vijayanathan V, Venkiteswaran S, Nair SK, Verma A, Thomas TJ, Zhu BT, Thomas T: Physiologic levels of 2-methoxyestradiol interfere with nongenomic signaling of 17beta-estradiol in human breast cancer cells. Clin Cancer Res. 2006 Apr 1;12(7 Pt 1):2038-48. [Article]
  3. Lv XH, Shi DZ: Effects of levonorgestrel on reproductive hormone levels and their receptor expression in Mongolian gerbils (Meriones unguiculatus). Exp Anim. 2011;60(4):363-71. doi: 10.1538/expanim.60.363. [Article]
  4. Garcia-Becerra R, Borja-Cacho E, Cooney AJ, Jackson KJ, Lemus AE, Perez-Palacios G, Larrea F: The intrinsic transcriptional estrogenic activity of a non-phenolic derivative of levonorgestrel is mediated via the estrogen receptor-alpha. J Steroid Biochem Mol Biol. 2002 Nov;82(4-5):333-41. [Article]
  5. Lemus AE, Vilchis F, Damsky R, Chavez BA, Garcia GA, Grillasca I, Perez-Palacios G: Mechanism of action of levonorgestrel: in vitro metabolism and specific interactions with steroid receptors in target organs. J Steroid Biochem Mol Biol. 1992 Mar;41(3-8):881-90. [Article]
Pharmacological action
General Function
Zinc ion binding
Specific Function
Steroid hormone receptors are ligand-activated transcription factors that regulate eukaryotic gene expression and affect cellular proliferation and differentiation in target tissues. Transcription ...
Gene Name
Uniprot ID
Uniprot Name
Androgen receptor
Molecular Weight
98987.9 Da
  1. Shields-Botella J, Duc I, Duranti E, Puccio F, Bonnet P, Delansorne R, Paris J: An overview of nomegestrol acetate selective receptor binding and lack of estrogenic action on hormone-dependent cancer cells. J Steroid Biochem Mol Biol. 2003 Nov;87(2-3):111-22. [Article]
  2. Freyberger A, Weimer M, Tran HS, Ahr HJ: Assessment of a recombinant androgen receptor binding assay: initial steps towards validation. Reprod Toxicol. 2010 Aug;30(1):2-8. doi: 10.1016/j.reprotox.2009.10.001. Epub 2009 Oct 13. [Article]
  3. Kloosterboer HJ, Vonk-Noordegraaf CA, Turpijn EW: Selectivity in progesterone and androgen receptor binding of progestagens used in oral contraceptives. Contraception. 1988 Sep;38(3):325-32. [Article]
  4. Christina Vrettakos; Tushar Bajaj (2019). Levonorgestrel. Stat Pearls NIH.
Pharmacological action
General Function
Androgen binding
Specific Function
Functions as an androgen transport protein, but may also be involved in receptor mediated processes. Each dimer binds one molecule of steroid. Specific for 5-alpha-dihydrotestosterone, testosterone...
Gene Name
Uniprot ID
Uniprot Name
Sex hormone-binding globulin
Molecular Weight
43778.755 Da
  1. Hammond GL, Abrams LS, Creasy GW, Natarajan J, Allen JG, Siiteri PK: Serum distribution of the major metabolites of norgestimate in relation to its pharmacological properties. Contraception. 2003 Feb;67(2):93-9. [Article]
  2. Hammond GL, Rabe T, Wagner JD: Preclinical profiles of progestins used in formulations of oral contraceptives and hormone replacement therapy. Am J Obstet Gynecol. 2001 Aug;185(2 Suppl):S24-31. [Article]
  3. Alvarez F, Brache V, Tejada AS, Cochon L, Faundes A: Sex hormone binding globulin and free levonorgestrel index in the first week after insertion of Norplant implants. Contraception. 1998 Oct;58(4):211-4. [Article]
  4. Song S, Chen JK, He ML, Fotherby K: Effect of some oral contraceptives on serum concentrations of sex hormone binding globulin and ceruloplasmin. Contraception. 1989 Apr;39(4):385-99. [Article]
Pharmacological action
General Function
Zinc ion binding
Specific Function
Receptor for glucocorticoids (GC). Has a dual mode of action: as a transcription factor that binds to glucocorticoid response elements (GRE), both for nuclear and mitochondrial DNA, and as a modula...
Gene Name
Uniprot ID
Uniprot Name
Glucocorticoid receptor
Molecular Weight
85658.57 Da
  1. Juchem M, Pollow K: Binding of oral contraceptive progestogens to serum proteins and cytoplasmic receptor. Am J Obstet Gynecol. 1990 Dec;163(6 Pt 2):2171-83. doi: 10.1016/0002-9378(90)90559-p. [Article]
  2. PharmGKB, Levonorgestrel [Link]


Pharmacological action
General Function
Oxygen binding
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally un...
Gene Name
Uniprot ID
Uniprot Name
Cytochrome P450 3A5
Molecular Weight
57108.065 Da
  1. Moreno I, Quinones L, Catalan J, Miranda C, Roco A, Sasso J, Tamayo E, Caceres D, Tchernitchin AN, Gaete L, Saavedra I: [Influence of CYP3A4/5 polymorphisms in the pharmacokinetics of levonorgestrel: a pilot study]. Biomedica. 2012 Oct-Dec;32(4):570-7. doi: 10.1590/S0120-41572012000400012. [Article]
  2. Edelman A, Munar M, Elman MR, Koop D, Cherala G: Effect of the ethinylestradiol/levonorgestrel combined oral contraceptive on the activity of cytochrome P4503A in obese women. Br J Clin Pharmacol. 2012 Sep;74(3):510-4. doi: 10.1111/j.1365-2125.2012.04209.x. [Article]
  3. Neary M, Lamorde M, Olagunju A, Darin KM, Merry C, Byakika-Kibwika P, Back DJ, Siccardi M, Owen A, Scarsi KK: The Effect of Gene Variants on Levonorgestrel Pharmacokinetics When Combined With Antiretroviral Therapy Containing Efavirenz or Nevirapine. Clin Pharmacol Ther. 2017 Sep;102(3):529-536. doi: 10.1002/cpt.667. Epub 2017 May 30. [Article]
Pharmacological action
General Function
Vitamin d3 25-hydroxylase activity
Specific Function
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It performs a variety of oxidation react...
Gene Name
Uniprot ID
Uniprot Name
Cytochrome P450 3A4
Molecular Weight
57342.67 Da
  1. Moreno I, Quinones L, Catalan J, Miranda C, Roco A, Sasso J, Tamayo E, Caceres D, Tchernitchin AN, Gaete L, Saavedra I: [Influence of CYP3A4/5 polymorphisms in the pharmacokinetics of levonorgestrel: a pilot study]. Biomedica. 2012 Oct-Dec;32(4):570-7. doi: 10.1590/S0120-41572012000400012. [Article]
  2. Edelman A, Munar M, Elman MR, Koop D, Cherala G: Effect of the ethinylestradiol/levonorgestrel combined oral contraceptive on the activity of cytochrome P4503A in obese women. Br J Clin Pharmacol. 2012 Sep;74(3):510-4. doi: 10.1111/j.1365-2125.2012.04209.x. [Article]
  3. Hatorp V, Hansen KT, Thomsen MS: Influence of drugs interacting with CYP3A4 on the pharmacokinetics, pharmacodynamics, and safety of the prandial glucose regulator repaglinide. J Clin Pharmacol. 2003 Jun;43(6):649-60. [Article]
  4. Levonorgestrel FDA label [Link]

Drug created at June 13, 2005 13:24 / Updated at July 19, 2024 07:26