Skip to main content
An official website of the United States government
Government Funding Lapse
Because of a lapse in government funding, the information on this website may not be up to date, transactions submitted via the website may not be processed, and the agency may not be able to respond to inquiries until appropriations are enacted.

The NIH Clinical Center (the research hospital of NIH) is open. For more details about its operating status, please visit cc.nih.gov.

Updates regarding government operating status and resumption of normal operations can be found at opm.gov.

levonorgestrel

The levorotatory form of norgestrel and synthetic progestogen with progestational and androgenic activity. Levonorgestrel binds to the progesterone receptor in the nucleus of target cells, thereby stimulating the resulting hormone-receptor complex, initiating transcription, and increasing the synthesis of certain proteins. This results in a suppression of luteinizing hormone (LH) activity and an inhibition of ovulation, as well as an alteration in the cervical mucus and endometrium.
Check for active clinical trials using this agentView this agent in the NCI Thesaurus
Synonym:18-Methylnorethisterone
D-(-)-Norgestrel
US brand name:Norplant
Plan B
Chemical structure:(17Alpha)-13-ethyl-17-hydroxy-18,19-dinorpregn-4-en-20-yn-3-one
13-Ethyl-17-hydroxy-18,19-dinor-17alpha-pregn-4-en-20-yn-3-one
Search NCI's Drug Dictionary
Please enter up to 30 characters for your search