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Systematic (IUPAC) name
Clinical data
AHFS/ International Drug Names
CAS Number 52-76-6 YesY
ATC code G03AC02 (WHO) G03DC03 (WHO);
G03AA03 (WHO) G03AB02 (WHO) G03FA07 (WHO) G03FB02 (WHO) (combinations with estrogens)
PubChem CID 5857
ChemSpider 5648 YesY
KEGG D01580 YesY
Chemical data
Formula C20H28O
Molar mass 284.436 g/mol

Lynestrenol (INN, USAN, BAN, JAN), also known as 17α-ethinyl-3-desoxy-19-nortestosterone or 17α-ethynyl-4-estren-17β-ol, is a steroidal progestin. It is a synthetic, orally active progestogen associated with numerous effects of the natural progesterone hormone. Lynestrenol has a strong progestational effect on the uterine endometrium (transforming proliferative endometrium into secretory one), inhibits secretion of gonadotropin, suppresses maturation of follicles in the ovaries and ovulation, reduces menstrual bleeding. This synthetic gestagen is associated with minimal estrogenic, androgenic and anabolic effects. Lynestrenol is used in treatment of hormonal disorders and diseases caused by insufficient secretion of the natural progesterone, except in case of risky pregnancies and prevention of miscarriage, since it is not efficient enough in this indication.


After oral administration lynestrenol is quickly resorbed and converted into pharmacologically active norethisterone, through which it demonstrates the main biological effects. The peak blood are reached within 2–4 hours after oral administration, 97% of the administered dose being bound to plasma proteins. Lynestrenol and its metabolites are predominantly excreted in the urine, less through feces, active metabolite norethisterone elimination halftime being 16-17 h.


Lynestrenol synthesis:[1][2]

In another approach to analogs, nortestosterone (1) is first converted to the dithioketal (2) by treatment with dithioglycol in the presence of boron trifluoride. (The mild conditions of this reaction compared to those usually employed in preparing the oxygen ketals probably accounts for the double bond remaining at 4,5). Treatment of this derivative with sodium in liquid ammonia affords the 3-desoxy analog (3). Oxidation by means of Jones reagent followed by ethynylation of the 17-ketone leads to the orally active progestin (6).

Positional isomers[edit]

These are easily confused.

Tigestol (C5=C10 olefin) synthesis: GB 841411  (1960 to ORGANON LABOR LTD).


Lynestrenol was introduced in the early 1960s.[3]