Skip to main content

Estradiol Cypionate use while Breastfeeding

Medically reviewed by Last updated on May 26, 2023.

Drugs containing Estradiol Cypionate: Estrace, Vagifem, Estradiol Patch, Estrace Vaginal Cream, CombiPatch, Myfembree, Estrogel, Yuvafem, Climara, Progynova, Show all 117 »Imvexxy, Divigel, Estrogen Patches, Estring, Climara Pro, Activella, Vivelle-Dot, Lyllana, Dotti, Oestrogel, Vivelle, Natazia, Estreva, Angeliq, Estrofem, Estraderm, Bijuva, Estradot, Oriahnn, Evorel, Depo-Estradiol, Prefest, Alora, Delestrogen, Amabelz, Minivelle, Evamist, Femring, Elleste Solo, Primogyn Depot, Oestrodose, Systen, Mimvey, Fempatch, Esclim, Aerodiol, Sandrena, Climodien, Oestradiol Implants, Elestrin, Femtrace, Lunelle, Ena, Valergen, Depogen, Dep Gynogen, Gynogen LA 20, Dioval 40, Dioval XX, Duragen, Estra-C, Estra-V 40, Estro-Cyp, Gynodiol, Estro-Span 40, Medidiol 10, Dura-Estrin, Estragyn LA 5, Oesclim, Clinagen LA 40, Estro-LA, Menaval-20, Estradot 37.5, Estradot 50, Estradot 75, Estradot 100, Oestrogel Pump-Pack, Dermestril, FemSeven, Progynova TS, Zumenon, Adgyn Estro, Fematrix, FemSeven Sequi Phase I, Menorest Patch, Nuvelle TS Phase I, Climaval, FemTab, Estrasorb, Femtran, Organon Oestradiol, Bedol, Delidose, Dermestril Septem, Estradiol G GAM, Estrapatch, Femsept, Menorest, Oromone, Provames, Thais, Thaissept, Menostar, Estra Pellets, Etyqa, Lopreeza, Mimvey Lo, Ortho-Prefest, Depo-Testadiol, Depotestogen, Dep Androgyn, Delatestadiol, Estra-Testrin, Valertest No 1, Duo-Cyp, Dura-Dumone, Duratestrin

Estradiol Cypionate Levels and Effects while Breastfeeding

Summary of Use during Lactation

Estradiol cypionate has not been studied during breastfeeding. However, a similar drug, estradiol valerate, has been used to suppress lactation, usually in combination with testosterone. Generally, estradiol cypionate should be avoided in mothers wishing to breastfeed, especially if started before the milk supply is well established at about 6 weeks postpartum. The decrease in milk supply can happen over the first few days of estrogen exposure.[1]

Drug Levels

Maternal Levels. Relevant published information on estradiol cypionate was not found as of the revision date. However, estradiol appears in breastmilk in small amounts after administration by other routes.[2,3]

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

Effects on Lactation and Breastmilk

Another injection ester form of estradiol, estradiol valerate was previously used therapeutically to suppress lactation, usually in combination with testosterone.[4-6]

A retrospective cohort study compared 371 women who received high-dose estrogen (either 3 mg of diethylstilbestrol or 150 mcg of ethinyl estradiol daily) during adolescence for adult height reduction to 409 women who did not receive estrogen. No difference in breastfeeding duration was found between the two groups, indicating that high-dose estrogen during adolescence has no effect on later breastfeeding.[7]

Alternate Drugs to Consider

Ethinyl Estradiol


Moses-Kolko EL, Berga SL, Kalro B, et al. Transdermal estradiol for postpartum depression: A promising treatment option. Clin Obstet Gynecol 2009;52:516-29. [PMC free article: PMC2782667] [PubMed: 19661765]
Nilsson S, Nygren KG, Johansson ED. Transfer of estradiol to human milk. Am J Obstet Gynecol 1978;132:653-7. [PubMed: 717472]
Perheentupa A, Critchley HO, Illingworth PJ, McNeilley AS. Enhanced sensitivity to steroid-negative feedback during breast-feeding: Low-dose estradiol (transdermal estradiol supplementation) suppresses gonadotropins and ovarian activity assessed by inhibin B. J Clin Endocrinol Metab 2000;85:4280-6. [PubMed: 11095468]
Louviere RL, Upton RT. Evaluation of Deladumone OB in the suppression of postpartum lactation. Am J Obstet Gynecol 1975;121:641-2. [PubMed: 1090174]
Morris JA, Creasy RK, Hohe PT. Inhibition of puerperal lactation. Double-blind comparison of chlorotrianesene, testosterone enanthate with estradiol valerate and placebo. Obstet Gynecol 1970;36:107-14. [PubMed: 4912251]
Iliya FA, Safon L, O'Leary JA. Testosterone enanthate (180 mg.) and estradiol valerate (8 mg.) for suppression of lactation: A double-blind evaluation. Obstet Gynecol 1966;27:643-5. [PubMed: 5949195]
Jordan HL, Bruinsma FJ, Thomson RJ, et al. Adolescent exposure to high-dose estrogen and subsequent effects on lactation. Reprod Toxicol 2007;24:397-402. [PubMed: 17531440]

Substance Identification

Substance Name

Estradiol Cypionate

CAS Registry Number


Drug Class

Breast Feeding


Milk, Human



Disclaimer: Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.