Last update Dec. 4, 2022

Gonadorelin (GnRH)

Likely Compatibility

Fairly safe. Mild or unlikely adverse effects. Compatible under certain circumstances. Follow-up recommended. Read Commentary.

It is a synthetic decapeptide identical to the physiological gonadotropin-releasing hormone (GnRH) secreted by the hypothalamus, which stimulates the pituitary release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) that stimulate the ovary to produce follicles. It is used as an assisted reproductive treatment to induce ovulation in anovulatory women with primary hypothalamic amenorrhea. It is also used in the diagnosis of hypothalamic-pituitary-gonadal dysfunction. Intravenous or subcutaneous administration.

At the date of the last update we did not find any published data on its excretion in breast milk.

Its high molecular weight and very short half-life make it unlikely that significant amounts will transfer into breastmilk. Gonadorelin has been detected in breast milk at very low concentrations: 0,1 - 3 ng/mL. (Hale)

Due to its protein nature, it is inactivated in the gastrointestinal tract (Van Leusden 1994, Fraser 1993), not being absorbed (practically zero oral bioavailability), which hinders its transfer into the infant's plasma from breastmilk, except in premature infants and the immediate neonatal period, when there may be greater intestinal permeability.

A similar analogue, buserelin, is excreted in breastmilk in negligible or undetectable amounts and did not cause hormonal alterations in infants breastfed by mothers who were taking it (Dewart 1987), or alterations in lactation. (Fraser 1989)

Increased prolactin has been observed in women treated with gonadorelin analogues and gonadotropins (Cavagna 2005, Kamel 1994, Meldrum 1992), although the findings are not consistent. (Chantilis 1995)


  • Buserelin (Safe substance and/or breastfeeding is the best option.)

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

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Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

Gonadorelin (GnRH) is also known as

Gonadorelin (GnRH) in other languages or writings:


Gonadorelin (GnRH) belongs to these groups or families:


Main tradenames from several countries containing Gonadorelin (GnRH) in its composition:


Variable Value Unit
Oral Bioavail. 0 %
Molecular weight 1.182 daltons
VD 0.14 l/Kg
pKa 9.47 -
0.1 - 0.7 hours
Theoretical Dose 0.000015 - 0.00045 mg/Kg/d
Relative Dose 4.5 - 27 %


  1. Hale TW. Medications & Mothers' Milk. 1991- . Springer Publishing Company. Available from Consulted on April 10, 2024 Full text (link to original source)
  2. Cavagna M, Mantese JC, Freitas Gda C, Dzik A, Soares JB, Hameiry Y, Izzo VM, Pinotti JA. Pattern of prolactin secretion after administration of gonadotropin-releasing hormone agonist at the preovulatory phase of intrauterine insemination cycles. Sao Paulo Med J. 2005 Nov 3;123(6):295-7. Epub 2006 Jan 20. Abstract
  3. Chantilis SJ, Barnett-Hamm C, Byrd WE, Carr BR. The effect of gonadotropin-releasing hormone agonist on thyroid-stimulating hormone and prolactin secretion in adult premenopausal women. Fertil Steril. 1995 Oct;64(4):698-702. Abstract
  4. Kamel MA, Zabel G, Bernart W, Neulen J, Breckwoldt M. Comparison between prolactin, gonadotrophins and steroid hormones in serum and follicular fluid after stimulation with gonadotrophin-releasing hormone agonists and human menopausal gonadotrophin for an in-vitro fertilization programme. Hum Reprod. 1994 Oct;9(10):1803-6. Abstract
  5. Van Leusden HA. Impact of different GnRH analogs in benign gynecological disorders related to their chemical structure, delivery systems and dose. Gynecol Endocrinol. 1994 Sep;8(3):215-22. Review. Abstract
  6. Fraser HM. GnRH analogues for contraception. Br Med Bull. 1993 Jan;49(1):62-72. Review. Abstract
  7. Meldrum DR, Cedars MI, Hamilton F, Huynh D, Wisot A, Marr B. Leuprolide acetate elevates prolactin during ovarian stimulation with gonadotropins. J Assist Reprod Genet. 1992 Jun;9(3):251-3. Abstract
  8. Fraser HM, Dewart PJ, Smith SK, Cowen GM, Sandow J, McNeilly AS. Luteinizing hormone releasing hormone agonist for contraception in breast feeding women. J Clin Endocrinol Metab. 1989 Nov;69(5):996-1002. Abstract
  9. Dewart PJ, McNeilly AS, Smith SK, Sandow J, Hillier SG, Fraser HM. LRH agonist buserelin as a post-partum contraceptive: lack of biological activity of buserelin in breast milk. Acta Endocrinol (Copenh). 1987 Feb;114(2):185-92. Abstract

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