I am not claiming early or prophylactic HCQ + zinc works. I am just pointing out why these studies don't prove it doesn't. Scepticism is good. Pretty essential for actual scientific method. We are really talking about hypothesis formation here. If you have the wrong hypothesis, your study proves nothing. Most of these "studies" are not even experiments. They are data mining. If the working thing never occurred in that data, you will not find it.

I've stated the hypothesis that some qualified medical professionals have advanced based on peer-reviewed journal papers. Clinical trials are underway to see if it works under those conditions. I have no dog in this fight, no stock in the company that makes it. But I see a lot of stupid mistakes being made over and over. If we get a good study that tests this hypothesis, and it doesn't work, then great. We will actually know something.

Yes, the evidence is in vitro. But some of that in vitro work was using cultured human cells, and this drug has been used in billions of human doses. So a lot of the reasons for in vitro --> in vivo failures have been eliminated.