You do realize that, unlike most scientists, I have actual patient care experience, right?

So what? Clinical trials have actual patient users too. Your anecdote with patients (that likely never experience anything even related to this post) is totally irrelevant, stop trying to look smart.

To start, supplements don't have guaranteed purity and quality control in places

Ok. So do your research before you buy.

Non-extreme zinc supplementation can lead to copper deficiency, which can lead to depression.

Ok so now for some real science:

Copper deficiency can be induced by disease states (Wilson disease and Menkes syndrome), excess losses (nephrotic syndrome) or inadequate dietary intake of copper; of interest to zinc is how zinc supplementation can induce a copper deficiency which has been reported in humans using up to 600mg elemental zinc daily[259] or excessive usage of zinc-based dental adhesives (a tube a day).

The top comment recommender 50mg. An unsafe amount is 600mg+ supplemented consistently every single day.

Clinical trials are expensive

And yet plenty of studies and trials exist for all of what was listed.

L-Arginine: http://www.ncbi.nlm.nih.gov/pubmed/18325648

Up to 20g per day without side effects, top comment recommended 1g.

Already went over zinc.

Lecithin is an FDA approved (and well known) food-additive with only known side-effects being cramping and diarrhea.

Pygeum, also studied and known/accepted as safe by the FDA, leads only to stomach pain and nausea if taken in high doses.

Nobody even mentioned any actual vitamins. You are not a clinical researcher, and you could have found all of this research very easily on your own.