I doubt that it is zinc itself the one causing these problems - most probably this is some additive in the particular product that you are using, so I would consider switching it, and seeing by yourself if things will change, of which I am sure. Also, I would like to add that although zinc is beneficial for natural testosterone production, on its own it won't do much, so it is best to take is as part of a supplemental stack, such as the above mentioned HCGenerate ES (btw - it works like a charm).