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2D structure from PubChem
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Generic Names
  • etonogestrel
Trade Names
  • Implanon
Brand Mixture Names
  • Nuvaring (Ethinyl Estradiol + Etonogestrel)

PharmGKB Accession Id:


Etonogestrel is a molecule used in hormonal contraceptives, most notably the subdermal implant Implanon. Wikipedia

Source: Drug Bank


For use as a female contraceptive (depot).

Source: Drug Bank

Other Vocabularies

Information pulled from DrugBank has not been reviewed by PharmGKB.

Pharmacology, Interactions, and Contraindications

Mechanism of Action

Etonogestrel binds to the progesterone and estrogen receptors. Target cells include the female reproductive tract, the mammary gland, the hypothalamus, and the pituitary. Once bound to the receptor, progestins like etonogestrel will slow the frequency of release of gonadotropin releasing hormone (GnRH) from the hypothalamus and blunt the pre-ovulatory LH (luteinizing hormone) surge.

Source: Drug Bank


Etonogestrel is used as a female contraceptive. Etonogestrel is a progestin or a synthetic form of the naturally occurring female sex hormone, progesterone. In a woman's normal menstrual cycle, an egg matures and is released from the ovaries (ovulation). The ovary then produces progesterone, preventing the release of further eggs and priming the lining of the womb for a possible pregnancy. If pregnancy occurs, progesterone levels in the body remain high, maintaining the womb lining. If pregnancy does not occur, progesterone levels in the body fall, resulting in a menstrual period. Etonogestrel tricks the body processes into thinking that ovulation has already occurred, by maintaining high levels of the synthetic progesterone. This prevents the release of eggs from the ovaries.

Source: Drug Bank

Food Interaction

Avoid alcohol.|Increase dietary intake of magnesium, folate, vitamin B6, B12, and/or consider taking a multivitamin.|Avoid excessive quantities of coffee or tea (Caffeine).|Take with food.|Take at the same time everyday.

Source: Drug Bank

Absorption, Distribution, Metabolism, Elimination & Toxicity



Source: Drug Bank


25 hours

Source: Drug Bank


Symptoms of overdose include nausea, vomiting, vaginal bleeding, and other menstrual irregularities.

Source: Drug Bank

Route of Elimination

Excretion of ENG and its metabolites, either as free steroid or as conjugates, is mainly in urine and to a lesser extent in feces.

Source: Drug Bank

Volume of Distribution

  • 201 L

Source: Drug Bank

Chemical Properties

Chemical Formula


Source: Drug Bank

Isomeric SMILES


Source: Drug Bank


Source: Drug Bank

Canonical SMILES


Source: Drug Bank

Average Molecular Weight


Source: Drug Bank

Monoisotopic Molecular Weight


Source: Drug Bank

Genes that are associated with this drug in PharmGKB's database based on (1) variant annotations, (2) literature review, (3) pathways or (4) information automatically retrieved from DrugBank, depending on the "evidence" and "source" listed below.

Drug Targets

Gene Description
ESR1 (source: Drug Bank)
PGR (source: Drug Bank)

Drug Interactions

Drug Description
etonogestrel Thiopental may decrease the effect of Etonogestrel. Contraceptive failure may occur. Alternative nonhomomonal contraception should be used during concomitant therapy. (source: Drug Bank)
etonogestrel Thiopental may decrease the effect of Etonogestrel. Contraceptive failure may occur. Alternative nonhomomonal contraception should be used during concomitant therapy. (source: Drug Bank)
etonogestrel Oral Tretinoin may decrease the effect of oral contraceptive, Etonogestrel. An alternate form of contraception should be used during concomitant therapy. (source: Drug Bank)
etonogestrel Etonogestrel may alter the anticoagulant effect of warfarin. Concomitant therapy should be avoided. Monitor for changes in coagulation status if etonogestrel is initiated, discontinued or dose changed. (source: Drug Bank)
No related diseases are available


Web Resource:
National Drug Code Directory:
PubChem Compound:
PubChem Substance:
Drugs Product Database (DPD):
Therapeutic Targets Database:
FDA Drug Label at DailyMed:

Clinical Trials

These are trials that mention etonogestrel and are related to either pharmacogenetics or pharmacogenomics.

No trials found.

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Sources for PharmGKB drug information: DrugBank, Open Eye Scientific Software.