Last update Sept. 23, 2023



Very unsafe. Contraindicated. Use of an alternative or cessation of breastfeeding. Read the Commentary.

A synthetic steroid with antigonadotropic and antiestrogenic activity due to the suppression of the pituitary gland’s gonadotropic hormone and with androgenic effects (Sanofi 2017, AEMPS 2017). Used to treat endometriosis, fibrocystic breast disease, hereditary angioedema, mastalgia, premenstrual syndrome and menorrhagia. Administration orally twice a day.

Since the last update we have not found published data on its excretion in breastmilk or its effect on breastfed infants.

In the absence of data regarding protein binding and the volume of distribution, the known pharmacokinetic data (low molecular weight, high pKa and prolonged half-life) make it likely that it would transfer to milk in amounts which could be significant.

Because of its potential androgenic effect on the infant and prolactin inhibition, it should be avoided during breastfeeding (Hale 2019 p193, Sanofi 2017, AEMPS 2017, Briggs 2015) and replaced by known safe alternatives. (Yeich 2023, Bouillet 2015)


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.

Other names

Danazol in other languages or writings:


Main tradenames from several countries containing Danazol in its composition:


Variable Value Unit
Oral Bioavail. 100 %
Molecular weight 338 daltons
pKa 17.59 -
Tmax 2 hours
4.5 - 29 hours


  1. Hale TW. Medications & Mothers' Milk. 1991- . Springer Publishing Company. Available from Consulted on April 10, 2024 Full text (link to original source)
  2. Yeich A, Elhatw A, Ashoor Z, Park K, Craig T. Safety of medications for hereditary angioedema during pregnancy and lactation. Expert Opin Drug Saf. 2023 Jan;22(1):17-24. Consulted on Sept. 22, 2023 Abstract
  3. AEMPS. Danazol. Ficha técnica. 2017 Full text (in our servers)
  4. Sanofi. Danazol. Drug Summary. 2017 Full text (in our servers)
  5. Bouillet L, Lehmann A, Gompel A, Boccon-Gibod I, Launay D, Fain O; CREAK.. Traitements des angiœdèmes héréditaires : recommandations du centre de référence national des angiœdèmes (consensus 2014 de Bordeaux). [Hereditary angiœdema treatments: Recommendations from the French national center for angiœdema (Bordeaux consensus 2014)]. Presse Med. 2015 Abstract
  6. Briggs GG, Freeman RK, Towers CV, Forinash AB. Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk. Wolters Kluwer Health. Tenth edition (acces on line) 2015

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