Last update Dec. 4, 2022


Low Risk

Possibly safe. Probably compatible. Mild risk possible. Follow up recommended. Read the Comment.

It is a tripeptide, synthetic analogue of the endogenous peptide thyrotropin-releasing hormone (TRH) released by the hypothalamus, which stimulates the release of thyroid-stimulating hormone (TSH) and prolactin from the anterior pituitary. It is used as a diagnostic test to evaluate thyroid function. Intravenous or intranasal 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.

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.

There may be galactorrhea or increased milk production due to prolactin stimulation. (Gosi 2022, Tyson 1972


We do not have alternatives for Protirelin.

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

Protirelin is also known as

Protirelin in other languages or writings:


Protirelin belongs to this group or family:


Main tradenames from several countries containing Protirelin in its composition:


Variable Value Unit
Oral Bioavail. 0 %
Molecular weight 362 daltons
VD 0.2 - 0.3 l/Kg
pKa 11.15 -
Tmax 0.1 - 0.2 hours
0.3 - 0.5 hours


  1. Gosi SKY, Garla VV. Galactorrhea. 2022 Aug 22. StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Abstract
  2. Bajoria R, Oteng-Ntim E, Peek MJ, Fisk NM. Pharmacokinetics and pharmacodynamics of TRH during pregnancy. Obstet Gynecol. 1997 Aug;90(2):176-82. Abstract
  3. Duntas L, Keck FS, Loos U, Pfeiffer EF. [Pharmacokinetics and pharmacodynamics of protirelin (TRH) in man]. Dtsch Med Wochenschr. 1988 Sep 2;113(35):1354-7. German. Abstract
  4. Tyson JE, Friesen HG, Anderson MS. Human lactational and ovarian response to endogenous prolactin release. Science. 1972 Sep 8;177(4052):897-900. Abstract

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