The Hydroxychloroquine hype was just like this. Then it was refuted in trials.

Without high-quality trials, we've got a couple of systematic reviews. One concluding that it helps. But it has been noticed that the effect it noticeable only in the poorer quality studies. Which usually means that what we're looking at is bias in the experiments rather than a genuine effect.

We need a large well blinded, randomized, placebo controlled trial. Until then we're just fucking guessing.