Nestorone

Nestorone

Systematic (IUPAC) name
(17α)-17-acetyl-16-methylene-3-oxoestr-4-en-17-yl acetate
Clinical data
Legal status	℞ (Prescription only)
Routes of administration	Subcutaneous implant, vaginal ring, transdermal patch
Pharmacokinetic data
Bioavailability	10% (oral)
Biological half-life	1-2 hours (oral)
Identifiers
CAS Number	7759-35-5
ATC code	None
PubChem	CID: 108059
ChemSpider	97161
Chemical data
Formula	C23H30O4
Molecular mass	370.482 g/mol
SMILES O=C4\C=C2/[C@@H]([C@H]1CC[C@@]3([C@](OC(=O)C)(C(=C)\C[C@H]3[C@@H]1CC2)C(=O)C)C)CC4
InChI InChI=1S/C23H30O4/c1-13-11-21-20-7-5-16-12-17(26)6-8-18(16)19(20)9-10-22(21,4)23(13,14(2)24)27-15(3)25/h12,18-21H,1,5-11H2,2-4H3/t18-,19+,20+,21-,22-,23-/m0/s1 Key:CKFBRGLGTWAVLG-GOMYTPFNSA-N

Nestorone (or nesteron), also known as elcometrine and ST-1435, is a 19-norprogesterone derivative and steroidal progestin which is used as a hormonal contraceptive in several South American countries.

Nestorone is only weakly active orally, and is instead given as a subcutaneous implant. It is more than 100-fold times as potent when delivered subcutaneously relative to orally.

Nestorone acts primarily as a high-affinity agonist of the progesterone receptor. It lacks significant affinity for the androgen receptor, and accordingly, does not produce any androgenic or anabolic effects. It does not bind to the estrogen receptor either. Nestorone does however have some affinity for the glucocorticoid receptor, where it appears to act as an agonist, but it does not appear to produce any glucocorticoid side effects unless used at high doses. It does not bind to the mineralocorticoid receptor.

Nestorone does not bind to sex hormone-binding globulin, and is instead bound to serum albumin.

See also

• Levonorgestrel
• Etonogestrel
• Nomegestrol acetate