Last update April 28, 2026

17β-Hydroxy-19-nor-17α-pregn-4-en-20-yn-3-one

Compatible

Safe product and/or breastfeeding is the best option.

Norethisterone or Nornorethindrone is a contraceptive progestogen derived from 19-northstastterone used as a single product or associated with ethinylestradiol. Oral administration daily or in intramuscular injection every 8 weeks.

It is excreted in breast milk in clinically insignificant amounts (Betrabet 1987, Cooke 1985, Koetsawang 1982, Melis 1981, Toddywalla 1980, Saxena 1977) and no problems have been observed in infants whose mothers took it. (WHO 1994, Shaaban 1991, Giner 1976, Karim 1971)

Plasma levels of these infants were undetectable or very low.(Betrabet 1987)

No alterations have been observed in the amount or composition of breast milk in mothers treated with norethindrone (Seth 1977, Giner 1976). In 9% of cases, the norethisterone pill was discontinued due to side effects, including irregular bleeding. (West 1983)

WHO List of Essential Medicines 2002: rates it as compatible with breastfeeding after the 6th postnatal week. (WHO/OMS 2002)

For a detailed discussion with references:

  • on why non-hormonal methods are the first choice during the first 4–6 weeks postpartum, followed by IUDs and progestin implants,
  • on the potential problems associated with the use of combined estrogen-progestin contraceptives,
  • the possible decrease in milk production with estrogen use,
  • and why progestin-only contraceptives are preferable during breastfeeding,

see below: “(Combined Estrogen + Progestin Contraceptives, COCs)”


See below the information of these related products:

Alternatives

Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.
DONATE NOW

Other names

17β-Hydroxy-19-nor-17α-pregn-4-en-20-yn-3-one is Norethisterone in Chemical name.

Is written in other languages:

17β-Hydroxy-19-nor-17α-pregn-4-en-20-yn-3-one is also known as

Group

17β-Hydroxy-19-nor-17α-pregn-4-en-20-yn-3-one belongs to this group or family:

Tradenames

Main tradenames from several countries containing 17β-Hydroxy-19-nor-17α-pregn-4-en-20-yn-3-one in its composition:

List of 20 tradenames

Pharmacokinetics

Variable Value Unit
Oral Bioavail. 64 %
Molecular weight 298 daltons
Protein Binding 99 %
VD 4 l/Kg
pKa 17.59 -
Tmax 1 - 2 hours
T½ 8 - 10 hours
M/P ratio 0.3 -
Theoretical Dose 0.0001 - 0.0004 mg/Kg/d
Relative Dose 0.7 - 1.9 %

References

  1. WHO / UNICEF. BREASTFEEDING AND MATERNAL MEDICATION Recommendations for Drugs in the Eleventh WHO Model List of Essential Drugs. Department of Child and Adolescent Health and Development (WHO/UNICEF) 2002 Abstract Full text (link to original source) Full text (in our servers)
  2. WHO. Progestogen-only contraceptives during lactation: I. Infant growth. World Health Organization Task force for Epidemiological Research on Reproductive Health; Special Programme of Research, Development and Research Training in Human Reproduction. Contraception. 1994 Abstract
  3. WHO. Progestogen-only contraceptives during lactation: II. Infant development. World Health Organization, Task Force for Epidemiological Research on Reproductive Health; Special Programme of Research, Development, and Research Training in Human Reproduction. Contraception. 1994 Abstract
  4. Shaaban MM. Contraception with progestogens and progesterone during lactation. J Steroid Biochem Mol Biol. 1991 Abstract
  5. Betrabet SS, Shikary ZK, Toddywalla VS, Toddywalla SP, Patel D, Saxena BN. ICMR Task Force Study on hormonal contraception. Transfer of norethisterone (NET) and levonorgestrel (LNG) from a single tablet into the infant's circulation through the mother's milk. Contraception. 1987 Abstract
  6. Cooke ID, Back DJ, Shroff NE. Norethisterone concentration in breast milk and infant and maternal plasma during ethynodiol diacetate administration. Contraception. 1985 Abstract
  7. West CP. The acceptability of a progestagen-only contraceptive during breast-feeding. Contraception. 1983 Abstract
  8. Koetsawang S, Nukulkarn P, Fotherby K, Shrimanker K, Mangalam M, Towobola K. Transfer of contraceptive steroids in milk of women using long-acting gestagens. Contraception. 1982 Abstract
  9. Melis GB, Strigini F, Fruzzetti F, Paoletti AM, Rainer E, Düsterberg B, Fioretti P. Norethisterone enanthate as an injectable contraceptive in puerperal and non-puerperal women. Contraception. 1981 Abstract
  10. Toddywalla VS, Mehta S, Virkar KD, Saxena BN. Release of 19-nor-testosterone type of contraceptive steroids through different drug delivery systems into serum and breast milk of lactating women. Contraception. 1980 Mar;21(3):217-23. Abstract
  11. Seth U, Yadava HS, Agarwal N, Laumas KR, Hingorani V. Effect of a subdermal silastic implant containing norethindrone acetate on human lactation. Contraception. 1977 Abstract
  12. Saxena BN, Shrimanker K, Grudzinskas JG. Levels of contraceptive seroids in breast milk and plasma of lactating women. Contraception. 1977 Abstract
  13. Giner Velázquez J, Cortés Gallegos V, Sotelo López A, Bondani G. [Effect of daily oral administration of 0.350 mg of norethindrone on lactation and on the composition of milk]. Ginecol Obstet Mex. 1976 Abstract
  14. Karim M, Ammar R, el-Mahgoub S, el-Ganzoury B, Fikri F, Abdou I. Injected progestogen and lactation. Br Med J. 1971 Abstract Full text (link to original source) Full text (in our servers)

Total visits

1,929

Help us improve this entry

How to cite this entry

Do you need more information or did not found what you were looking for?

   Write us at elactancia.org@gmail.com

e-lactancia is a resource recommended by Instituto de Salud Infantil, Grecia-Institute of Child´s Health in Greece

Would you like to recommend the use of e-lactancia? Write to us at corporate mail of APILAM