Drug Levels and Effects:

Summary of Use during Lactation:

This record contains information specific to norethindrone used alone. Users with an interest in a combination oral contraceptive should consult the record entitled, "Contraceptives, Oral, Combined."

Although nonhormonal methods are preferred during breastfeeding, progestin-only contraceptives such as norethindrone are considered the hormonal contraceptives of choice during lactation. Poor to fair quality evidence indicates that norethindrone does not adversely affect the composition of milk, the growth and development of the infant or the milk supply.[1][2][3] Some evidence indicates that progestin-only contraceptives may offer some protection against bone mineral density loss during lactation, or at least not exacerbate it.[4][5][6]

Based on the available evidence, expert opinion in the United States holds that the advantages of using progestin-only contraceptive products generally outweigh the theoretical or proven risks before 4 weeks postpartum.[7] However, is prudent to give it no sooner than 3 days postpartum when lactation is established.[2][3]

Drug Levels:

Maternal Levels.

Five women with well-established lactation (exact time postpartum not stated) were given an oral dose of 350 mcg of norethindrone daily. Breastmilk levels were measured several times on the first day of treatment. Peak milk levels occurred at 2 or 4 hours after the dose in various individuals. Average milk levels were 0.747 mcg/L at 2 hours after the dose; 0.747 mcg/L at 4 hours; 0.396 mcg/L at 8 hours; 0.253 mcg/L at 12 hours; and, 0.174 mcg/L at 12 hours after the dose.[8]

Milk norethindone levels were measured in 4 women after daily ingestion of oral norethindrone 350 mcg started after 3 months postpartum. Peak milk norethindrone levels in the range of 0.4 to 0.5 mcg/L occurred between 1 and 3 hours after the dose and dropped slowly over the 6-hour study interval to about 0.15 to 0.4 mcg/L.[9]

At 6 to 20 weeks postpartum, 15 women received a single tablet of a combination oral contraceptive containing a dose of 3 mg of norethindrone. At 2 to 2.5 hours after the dose, a foremilk sample was taken. The mothers breastfed their infants and then a hindmilk sample was taken. The two samples were pooled for assay. Milk levels averaged 2.4 mcg/L (range 0.9 to 5.5 mcg/L).[10]

Infant Levels.

At 6 to 20 weeks postpartum, 15 women received a single tablet of a combination oral contraceptive containing a dose of 3 mg of norethindrone. At 2 to 2.5 hours after the dose the mothers breastfed their infants; infant serum samples were taken 1.5 to 2 hours later at about 4 hours after the maternal dose. Infant serum levels averaged 0.19 mcg/L which was 0.8% of peak maternal serum levels drawn at 2 to 2.5 hours after the dose.[10]

Effects in Breastfed Infants:

No consistent physical, mental, or radiologic differences have been found in infants whose mothers were using norethindrone enanthate (Norplant).[11][12] Some studies found increased infant weight gain among the infants of treated women.[11][13][14]

A non-blinded, randomized study of exclusively breastfeeding women compared those who received an etonogestrel implant 24-48 hours after delivery (n = 20) to those who received a 150 mg depot medroxyprogesterone acetate injection at 6 weeks postpartum (n = 20). Infants of the implant users gained more than the infants of the DMPA mothers during the first 6 weeks of life.[15]

A short-term study of 12 women who received oral norethindrone 350 mcg daily starting 48 hours postpartum found no differences in infant weight gain over 14 days compared to 8 women taking a placebo.[16]

Possible Effects on Lactation:

Studies of varying size and quality on the use of long-acting norethindrone injections (acetate or enanthate) have found that the use of levonorgestrel implants (Norplant or Norplant-2) as a contraceptive beginning at 6 weeks postpartum or later either has no clinically important negative effect on the quality of breastmilk and results in either no effect or an increase in the milk supply and duration of lactation [11][12][13][14] In one study, women who received the implant at 6 days postpartum, a transient decrease in milk protein occurred 2 weeks after implant insertion. A decrease in milkphosphoruscontent was also observed between 2 and 4 months after implant insertion in this group and at 3 months postpartum, the early insertion group had a higher rate of supplementation.[17] In another study, women given norethindrone enanthate depot injection less than 48 hours postpartum were 2.5 to 3 times more likely to have postpartum depression at 6 weeks postpartum. No differences were seen at 1 and 12 weeks postpartum.[18]

A short-term study of 12 women who received oral norethindrone 350 mcg daily starting 48 hours postpartum found no differences in milk production or milk composition over 14 days compared to 8 women taking a placebo.[16]

One small, nonrandomized study found that oral norethindrone 350 mcg daily decreased the quantity and quality (lower protein, lipids and calcium) compared to controls who received nonhormonal contraception.[19]

In a nonrandomized, nonblinded study comparing women who were breastfeeding at discharge, 102 postpartum women received depot medroxyprogesterone acetate (dosage not stated) in the early postpartum period (average 51.9 hours postpartum; range 6.25 to 132 hours), 181 received another progestin-only contraceptive and 138 used nonhormonal contraception. No differences in breastfeeding rates were seen at 2 and 6 weeks, but women receiving any hormonal contraceptive were breastfeeding at a lower rate (72.1% vs 77.6%) at 4 weeks postpartum. The authors concluded that progestin-only contraception initiated in the early postpartum period had no adverse effects on breastfeeding rates.[20]

Alternate Drugs to Consider:

Etonogestrel,Levonorgestrel,Medroxyprogesterone Acetate


1. Truitt ST, Fraser AB, Grimes DA et al. Combined hormonal versus progestin-only contraception in lactation. Cochrane Database Syst Rev. 2003;2:CD003988 (updated 6 May 2008). PMID:12804497
2. Queenan JT. Contraception and breastfeeding. Clin Obstet Gynecol. 2004;47:734-9. PMID:15326435
3. Anon. FFPRHC Guidance (July 2004): Contraceptive choices for breastfeeding women. J Fam Plann Reprod Health Care. 2004;30:181-9. PMID:15222930
4. Caird LE, Reid-Thomas V, Hannan WJ et al. Oral progestogen-only contraception may protect against loss of bone mass in breast-feeding women. Clin Endocrinol (Oxf). 1994;41:739-45. PMID:7889609
5. Diaz S, Reyes MV, Zepeda A et al. Norplant(R) implants and progesterone vaginal rings do not affect maternal bone turnover and density during lactation and after weaning. Hum Reprod. 1999;14:2499-505. PMID:10527977
6. Costa ML, Cecatti JG, Krupa FG et al. Progestin-only contraception prevents bone loss in postpartum breastfeeding women. Contraception. 2012;85:374-80. PMID:22036473
7. Farr S, Folger SG, Paulen M et al. U S. medical eligibility criteria for contraceptive use, 2010: adapted from the World Health Organization medical eligibility criteria for contraceptive use, 4th edition. MMWR Recomm Rep. 2010;59 (RR-4):1-86. PMID:20559203
8. Saxena BN, Shrimanker K, Grudzinskas JG. Levels of contraceptive steroids in breast milk and plasma of lactating women. Contraception. 1977;16:605-13. PMID:606500
9. 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;21:217-22. PMID:7389350
10. Betrabet SS, Shikary ZK, Toddywalla VS et al. 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;35:517-22. PMID:3117488
11. Karim M, Ammar R, El Mahgoub S et al. Injected progestogen and lactation. Br Med J. 1971;1:200-3. PMID:5099971
12. Shaaban MM. Contraception with progestogens and progesterone during lactation. J Steroid Biochem Mol Biol. 1991;40:705-10. PMID:1835650
13. Anon. 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;50:55-68. PMID:7924322
14. Anon. 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;50:35-53. PMID:7924321
15. Brito MB, Ferriani RA, Quintana SM et al. Safety of the etonogestrel-releasing implant during the immediate postpartum period: a pilot study. Contraception. 2009;80:519-26. PMID:19913145
16. Giner Velazquez J, Cortes Gallegos V, Sotelo Lopez A et al. [Effect of daily oral administration of 0.350 mg of norethindrone on lactation and on the composition of milk]. Ginecol Obstet Mex. 1976;40:31-9. PMID:780215
17. Seth U, Yadava HS, Agarwal N et al. Effect of a subdermal silastic implant containing norethindrone acetate on human lactation. Contraception. 1977;16:383-98. PMID:923249
18. Lawrie TA, Hofmeyr GJ, De Jager M et al. A double-blind randomised placebo controlled trial of postnatal norethisterone enanthate: the effect on postnatal depression and serum hormones. Br J Obstet Gynaecol. 1998;105:1082-90. PMID:9800931
19. Toddywalla VS, Joshi L, Virkar K. Effect of contraceptive steroids on human lactation. Am J Obstet Gynecol. 1977;127:245-9. PMID:835620
20. Halderman LD, Nelson AL. Impact of early postpartum administration of progestin-only hormonal contraceptives compared with nonhormonal contraceptives on short-term breast-feeding patterns. Am J Obstet Gynecol. 2002;186:1250-8. PMID:12066106

Substance Identification:

Substance Name:


CAS Registry Number:


Drug Class:

  • Contraceptive Agents, Female

  • Contraceptives, Oral, Synthetic

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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