Zinc's Dopamine stimulant properties lower prolactin which can increase libido etc. High prolactin (levels rise after orgasm) in males usually results in lowered libido.
No, it doesn't. One might have expected such a thing on the basis of theory or in vitro data, but in humans, it doesn't happen, according to these guys:
J Trace Elem Med Biol. 2002;16(2):69-73.
Zinc supplementation does not inhibit basal and metoclopramide-stimulated prolactinemia secretion in healthy men.
Castro AV, Mendonça BB, Bloise W, Shuhama T, Brandão-Neto J.
Dopamine (DA) and zinc (Zn++) share common mechanisms in their inhibition of prolactin (PRL) secretion. Both substances are present in the same brain areas, where Zn++ is released together with DA, suggesting a modulatory effect of Zn++ on dopaminergic receptors. The aim of the present study was to evaluate the effect of Zn++ supplementation on basal and PRL secretion stimulated by metoclopramide (MCP), a dopaminergic antagonist. Seven healthy men were evaluated in controlled study, where MCP (5 mg) was given intravenously, before and after 3 months of oral Zn++ (25 mg) administration. Our results indicate that chronic Zn++ administration does not change basal or MCP-stimulated plasma PRL secretion suggesting that, in humans, Zn++ does not interfere on PRL secretion mediated through dopaminergic receptors.
PMID: 12195728