[ **up: [[Hormones]]** ] --- # Prolactin ## Prolactin & breast/chestfeeding > “Prolactin is a hormone that is well known for its role in promoting breast milk production. This is particularly true for females, where we see large spikes during pregnancy, especially during the third trimester.”[^1] --- ## Prolactin & the cis male body > “Males generally have lower serum concentrations of prolactin versus females.”[^1] > “Too much prolactin (hyperprolactinemia) in males can result in headaches, in addition to lowered libido and erectile dysfunction. This is of course due to the effects that elevated prolactin have on the hypothalamus-pituitary-testicular axis (HPTA). This of course can lead to lowered bone mass in normal males, due to lowered Testosterone and therefore lowered oestradiol. Prolactin actually has an inhibitory effect on the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus. Therefore, when high enough, this inhibitory effect caused by prolactin is great enough to induce tertiary hypogonadism, because if we inhibit the release of GnRH, there will be lower levels of LH and thus lower Testosterone produced by the Leydig cells, ultimately leading to tertiary hypogonadism. This is quite complex, given that in normal concentrations it actually improves Leydig cell function and general health.”[^1] > “High prolactin may even induce depressive symptoms (independent of it causing tertiary hypogonadism, so you are not immune if on TRT) and can encourage lactation.”[^1] > “Additionally, some other systematic disorders can lead to elevated prolactin, including the following: > > - Chronic kidney failure > - Liver cirrhosis > - Chest wall trauma, surgery, herpes zoster (chickenpox and/or shingles) > > It may even be due to a genetic cause, where the prolactin receptor is inactivated due to a gene mutation.”[^1] [^1]: Joseph Hearnshaw, ‘Prolactin – Man’s Friend or Foe?’, *The Men’s Health Clinic*, 23 October 2000, https://themenshealthclinic.co.uk/prolactin-mans-friend-or-foe/.