Zinc Seems To Acutely Reduce Prolactin

[cantstoppeating]

Zinc may acutely reduce prolactin levels, according to these studies:


Zinc: an inhibitor of prolactin (PRL) secretion in humans.
http://www.ncbi.nlm.nih.gov/pubmed/2753470
"The response of plasma prolactin (PRL) to oral administration of increasing doses of zinc (25.0, 37.5 and 50.0 mg) was studied in 17 normal adult men and women. Blood samples were collected at 10 and 30-min intervals over a period of 120 min after two basal times (-30 and 0 min). PRL concentrations significantly fell below basal levels in all subjects in response to the increase in plasma zinc levels, as compared to the controls. These results suggest that acute hyperzincemia can inhibit basal PRL secretion in normal individuals."

Zinc acutely, selectively and reversibly inhibits pituitary prolactin secretion.
http://www.ncbi.nlm.nih.gov/pubmed/6697238
"Perifusion of dispersed female rat pituitary cells with medium containing 50 microM zinc acetate caused an acute, sustained and rapidly reversible inhibition of prolactin (Prl) secretion. This treatment had no influence on basal release of thyrotropin stimulating hormone (TSH), luteinizing hormone (LH) or growth hormone (GH). 50 microM Zn2+ also reversibly inhibited prolactin secretion stimulated by either 50 mM K+ or 10 nM TRH, but the secretion of GH, TSH and LH which was stimulated by 50 mM K+ or stimulation of TSH by 10 nM TRH was not inhibited. Thus zinc acts in a dynamic manner to selectively influence pituitary prolactin secretion."


In another study however they found no reduction in prolactin, in women, from various intakes of zinc:

Zinc does not acutely suppress prolactin in normal or hyperprolactinemic women.
http://www.ncbi.nlm.nih.gov/pubmed/2491863
"...This study was done to investigate the serum PRL response to an oral zinc challenge in vivo. Eight hyperprolactinemic [mean serum PRL, 76.0 +/- 43.8 (+/- SD) micrograms/L] and 10 normal (mean serum PRL, 9.6 +/- 2.8 micrograms/L) women were studied. All women had normal thyroid, renal, and hepatic function, and none was taking any medications. Each was studied twice, after both oral zinc (50 mg) and placebo, given in random order. Blood was withdrawn every 15 min from 30 min before to 210 min after zinc or placebo administration; TRH (500 micrograms) was given iv at 180 min. Both hyperprolactinemic and normal women absorbed the zinc well, achieving similar maximal plasma zinc levels [hyperprolactinemic women, 39.5 +/- 6.9 (+/- SD) mumol/L; normal women, 33.3 +/- 7.0; P less than 0.001 vs. placebo]. When 2 women who became symptomatic after zinc administration were excluded, there were no significant differences in basal or TRH-stimulated serum PRL levels after zinc vs. placebo. These findings indicate that zinc is not involved in the acute in vivo regulation of PRL secretion in humans."


Given that many people see benefits from zinc, I'd consider it a worthy experiment to supplement it as zinc gluconate/sulphate (perhaps with the addition of copper to avoid its depletion), in daily doses of 25-50mg, or increase oyster intake.

 

[kineticz]

It boosts my testosterone pathways significantly. Trouble is, in adrenal fatigue and hypothyroidism, increased testosterone and reduced prolactin mean you have to step up efforts to replenish.

 

[haidut]

Zinc may acutely reduce prolactin levels, according to these studies:


Zinc: an inhibitor of prolactin (PRL) secretion in humans.
http://www.ncbi.nlm.nih.gov/pubmed/2753470
"The response of plasma prolactin (PRL) to oral administration of increasing doses of zinc (25.0, 37.5 and 50.0 mg) was studied in 17 normal adult men and women. Blood samples were collected at 10 and 30-min intervals over a period of 120 min after two basal times (-30 and 0 min). PRL concentrations significantly fell below basal levels in all subjects in response to the increase in plasma zinc levels, as compared to the controls. These results suggest that acute hyperzincemia can inhibit basal PRL secretion in normal individuals."

Zinc acutely, selectively and reversibly inhibits pituitary prolactin secretion.
http://www.ncbi.nlm.nih.gov/pubmed/6697238
"Perifusion of dispersed female rat pituitary cells with medium containing 50 microM zinc acetate caused an acute, sustained and rapidly reversible inhibition of prolactin (Prl) secretion. This treatment had no influence on basal release of thyrotropin stimulating hormone (TSH), luteinizing hormone (LH) or growth hormone (GH). 50 microM Zn2+ also reversibly inhibited prolactin secretion stimulated by either 50 mM K+ or 10 nM TRH, but the secretion of GH, TSH and LH which was stimulated by 50 mM K+ or stimulation of TSH by 10 nM TRH was not inhibited. Thus zinc acts in a dynamic manner to selectively influence pituitary prolactin secretion."


In another study however they found no reduction in prolactin, in women, from various intakes of zinc:

Zinc does not acutely suppress prolactin in normal or hyperprolactinemic women.
http://www.ncbi.nlm.nih.gov/pubmed/2491863
"...This study was done to investigate the serum PRL response to an oral zinc challenge in vivo. Eight hyperprolactinemic [mean serum PRL, 76.0 +/- 43.8 (+/- SD) micrograms/L] and 10 normal (mean serum PRL, 9.6 +/- 2.8 micrograms/L) women were studied. All women had normal thyroid, renal, and hepatic function, and none was taking any medications. Each was studied twice, after both oral zinc (50 mg) and placebo, given in random order. Blood was withdrawn every 15 min from 30 min before to 210 min after zinc or placebo administration; TRH (500 micrograms) was given iv at 180 min. Both hyperprolactinemic and normal women absorbed the zinc well, achieving similar maximal plasma zinc levels [hyperprolactinemic women, 39.5 +/- 6.9 (+/- SD) mumol/L; normal women, 33.3 +/- 7.0; P less than 0.001 vs. placebo]. When 2 women who became symptomatic after zinc administration were excluded, there were no significant differences in basal or TRH-stimulated serum PRL levels after zinc vs. placebo. These findings indicate that zinc is not involved in the acute in vivo regulation of PRL secretion in humans."


Given that many people see benefits from zinc, I'd consider it a worthy experiment to supplement it as zinc gluconate/sulphate (perhaps with the addition of copper to avoid its depletion), in daily doses of 25-50mg, or increase oyster intake.

Thanks. I think we've posted these studies on the forum about zinc before. It was in relation to vitamin E and other things that reduce prolactin. The problem is that there are at least 10 other studies that show no effect of zinc on prolactin in either healthy or kidney patients. So, it seems to be hit or miss with zinc but if you have a way to measure prolactin or testosterone levels before/after supplementation then it may be worth taking zinc for a month. I think Ray also caution against supplementing more than 30mg of zinc for more than a week but I can't find that reference.

 

[Parsifal]

Why does high zinc supplementation increase sebum? I thought it was due to prolactin?

 

[haidut]

Why does high zinc supplementation increase sebum? I thought it was due to prolactin?

If it is androgenic and raises T/DHT like some studies show, then it is quite natural to increase sebum production.

 

[mayweatherking]

Thanks. I think we've posted these studies on the forum about zinc before. It was in relation to vitamin E and other things that reduce prolactin. The problem is that there are at least 10 other studies that show no effect of zinc on prolactin in either healthy or kidney patients. So, it seems to be hit or miss with zinc but if you have a way to measure prolactin or testosterone levels before/after supplementation then it may be worth taking zinc for a month. I think Ray also caution against supplementing more than 30mg of zinc for more than a week but I can't find that reference.

Did you ever find that? I wonder what he would think if you have levels that are all ready very low. I bought a zinc "taste test" where supposedely i you don't taste zinc, then you are deficient in it. I have been doing it everyday and I seem not to budge, but tasting it a little more here and there. I feel way better increasing the zinc levels though, but I wonder when I will finally reach where I should be.

 

[haidut]

Did you ever find that? I wonder what he would think if you have levels that are all ready very low. I bought a zinc "taste test" where supposedely i you don't taste zinc, then you are deficient in it. I have been doing it everyday and I seem not to budge, but tasting it a little more here and there. I feel way better increasing the zinc levels though, but I wonder when I will finally reach where I should be.

I have not found it but I know the quote is on the forum. Ray said something about not using zinc for more than a few weeks due to oxidative stress concerns. And I think the dose he favored if used is much lower - 10mg max instead of the 30mg + people down daily.

 

[LukeL]

I have not found it but I know the quote is on the forum. Ray said something about not using zinc for more than a few weeks due to oxidative stress concerns. And I think the dose he favored if used is much lower - 10mg max instead of the 30mg + people down daily.

@haidut how often can I eat canned oysters? I want to avoid oxidative stress but still have the benefits of eating nutrient dense oysters...

 

[haidut]

@haidut how often can I eat canned oysters? I want to avoid oxidative stress but still have the benefits of eating nutrient dense oysters...

I think twice a week is probably fine, both for zinc and copper purposes.

 

[mayweatherking]

I have not found it but I know the quote is on the forum. Ray said something about not using zinc for more than a few weeks due to oxidative stress concerns. And I think the dose he favored if used is much lower - 10mg max instead of the 30mg + people down daily.

@haidut how often can I eat canned oysters? I want to avoid oxidative stress but still have the benefits of eating nutrient dense oysters...

I sent him an email asking him about both of those... here's what he had to say:

It’s safe at a level of ten mg per day, at least for a while. How much protein do you get daily? Oysters are a very good source.

I asked him about him recommending oysters only once or twice a week and if it's ok to have it more and about the "zinc taste test", he said:

Having oysters more often is o.k. Other nutrients affect taste sensitivity.