Lynestrenol is a synthetic progestogen used in oral contraceptives and treatments of other disorders. It is a prodrug of norethindrone, therefore its pharmacology is almost identical to NET.
KEGG Entry Number
Wikipedia Entry Name
White, crystalline powder
Practically insoluble in water; soluble in ethanol, acetone and diethyl ether; freely soluble in chloroform
Specific Optical Rotation
-13 ° in chloroform
GHS Hazard Code(s)
|Acute Oral Toxicity||4||H302||Harmful if swallowed|
|Acute Dermal Toxicity||4||H312||Harmful in contact with skin|
|Acute Inhalation Toxicity||4||H332||Harmful if inhaled|
|Carcinogenicity||2||H351||Suspected of causing cancer if inhaled|
|Reproductive Toxicity||1B||H360||May damage fertility or the unborn child|
As a prodrug of norethindrone that forms no other metabolites, the pharmacology of lynestrenol is essentially the same as norethindrone.
Progesterone Receptor Activity
Serum Protein Binding
97% bound to plasma proteins
Metabolized by CYP2C9, CYP2C19, CYP3A4 into ethynodiol, then norethindrone.
1 mg lynestrenol is bioequivalent to 0.7 mg norethindrone.
Norethindrone acetate, norethindrone enanthate, lynestrenol, and ethynodiol diacetate (and to a very small extent, norethynodrel) are prodrugs of norethindrone. Conversion of lynestrenol to ethynodiol to norethindrone facilitated by CYP2C9, CYP2C19, and CYP3A4. Conversion of norethynodrel to norethindrone is accomplished by either non-enzymatic or enzymatic ketosteroid isomerization.