No over-the-counter medication, supplement, or mineral will truly mitigate the effects of aromatizable AAS.
BONEZ is completely correct.
While Zinc does have a correlation to SLIGHTLY lowered aromatase, it will not stop estrogen related side effects for AAS.
Supplements, like the mentioned Novadex, do not contain SERMS or AIs, meaning that they cannot have a true anti-estrogen function. They do, however, contain small amounts of phytosterols which have claims of being anabolic and somehow anti-estrogenic, but no data I have ever heard of or seen supports this.
In terms of the biased, uncontrolled, and subjective reports made on forums and the internet reviewing these: They seem to be low enough in reported affect to be attributable to little more than placebo controls in well-organized studies.
The only true anti-estrogens are those used medically or being used within research (and I do not mean research chem sites, but true medical research) for further development of medical SERMS and AIs.