Prolactin is an innocent bystander and may even be beneficial

alfredoolivas

@sunsunsun mayhaps you expand on that?

sunsunsun

alfredoolivas

@sunsunsun yeah it probably increases metabolic efficiency, but that makes one fat & it directly breaks down muscle tissue via the elvation of le amino transferases

alfredoolivas

This study breaks it down nicely
https://academic.oup.com/endo/article/158/1/56/2751112?login=false

alfredoolivas

Prolactin mogs in glucose tolerance tests and this is observed IRL too

LunaticRed

@alfredoolivas Interesting, can you link this study?

alfredoolivas

@LunaticRed link above photo

cs3000

@alfredoolivas estrogen also helps in glucose intolerance in these models through signalling effects at the pancreas & lipogenesis lowering, so has different signalling ofc but prolactin is probably having estrogen like effects (shares some similar genes activation) (
https://pubmed.ncbi.nlm.nih.gov/12670737/
i read some connection a while back between prolactin and helping slow wave sleep though

high estrogen not good for mood & tumors but good for initial early regeneration, e.g when destroy pancreas cells with a substance or high fat, and lowers lipogenesis in some places so less to deal with on top of the high fat coming in. i guess prolactin shares some of the pathways / gene effects
https://academic.oup.com/endo/article-abstract/150/5/2109/2455831?login=false https://www.jci.org/articles/view/44564

so good in those HFD contexts & for that aspect , but when it signals high for a long time it can cause metabolic problems instead "There may be a “goldilocks zone” for serum prolactin that promotes metabolic homeostasis"

in a smaller case control study of 134 patients, the average concentration of prolactin in controls (18.38 µg/L) was found to be significantly higher than that of diabetic patients (5.39 µg/L) (109). Wang et al. also similarly showed that a high normal prolactin range (11.61-26.29 ng/mL) was most protective against insulin resistance and diabetes in a large cohort of patients with hyperprolactinemia

https://pubmed.ncbi.nlm.nih.gov/21557442/ shows high levels create metabolic problems , giving more but not high levels helped

alfredoolivas

@cs3000 I agree, the main point of this post was to warn people not to nuke it.

alfredoolivas

Human studies
"a 2-3 fold increase of circulating PRL levels maintained for 1.5-3 h exerted no apparent effects on the secretion of endogenous LH, FSH and TSH."
https://pubmed.ncbi.nlm.nih.gov/8258642/

"Prolactin does not acutely influence renal electrolyte excretion and probably does not influence water excretion in man."
https://pubmed.ncbi.nlm.nih.gov/870513/

alfredoolivas

Prolactin group had much lower estradiol, but the before measurements were not taken

https://clinicaltrials.gov/study/NCT00438490?tab=results#results-overview

https://pmc.ncbi.nlm.nih.gov/articles/PMC1950489/#sec10

Prolactin group had constantly lower estradiol

Prolactin group ate less

"Short-term prolactin administration causes expressible galactorrhea but does not affect bone turnover:"

engineer

@alfredoolivas so with how good prolactin is, tell us why we shouldn't prolactinmaxx (you know how)

alfredoolivas

@engineer I have been doing that with great results.

Ecstatic_Hamster

thank you all for this incredibly valuable thread. @alfredoolivas thanks for starting it.

I suppose like estrogen, prolactin has its good sides. This has helped me see some more research material I would have missed that I can study.

alfredoolivas

After quitting cabergoline, my tiredness has stoppped

engineer

@alfredoolivas at this point I would be worried about not getting in enough food or at least not carb cycling (to lose fat by maximizing carbs only when absolutely needed), because you can feel "not tired" through cortisol which could have been suppressed with cabergoline

alfredoolivas

@engineer cabergoline increases noradrenaline though.

alfredoolivas

“PRL stimulates steroidogenesis in the testes by inducing or maintaining LH receptors in Leydig cells and/or by affecting androgen biosynthesis in Leydig cells via steroidogenic enzymes activity”

https://pmc.ncbi.nlm.nih.gov/articles/PMC10637432/

Kvirion

"The dose makes the poison."

"Alle Dinge sind Gift, und nichts ist ohne Gift; allein die Dosis macht, daß ein Ding kein Gift ist." ~Paracelsus

alfredoolivas

No evidence for prolactin’s involvement in the post-ejaculatory refractory period

Prolactin is released during sexual behavior in male mice.
"Baseline levels of circulating PRL in male mice were low for both strains (**BL6 0.86 ± 0.46; PWK: 2.31 ± 1.37 ng/ml; please see ref. 46 for BL6), but are significantly increased during sexual interaction (Bl6: F3,7 = 21.26, P < 0.0001; PWK: F3,8 = 17.18, P < 0.0001; RM one-way ANOVA) (Fig. 1a)."

Acute prolactin release does not induce a refractory period-like state.

"However, the involvement of PRL in the establishment and duration of the PERP is controversial and has not been formally tested"

"The fact that PRL levels are already elevated during sexual interaction in BL6 and PWK males further suggests that PRL cannot promote by itself reduced sexual activity, at least in male mice"

Mice have different prolactin responses to ejaculation then humans, but it was interesting experiment that does demonstrate how little is known about independent prolactin.