But concerning controversy surrounding ivermectin I found this interesting text:

An important controversial point to consider in any rationale is the 5 µM required concentration to reach the anti-SARS-CoV-2 action of ivermectin observed in vitro,17 which is much higher than 0.28 µM, the maximum reported plasma concentration achieved in vivo with a dose of approximately 1700 µg/kg (about nine times the FDA-approved dosification).24 25 In this sense, basic fundamentals for assessing ivermectin in COVID-19 at a clinical level appear to be insufficient. Among other reasons, we believe this might have led WHO to exclude ivermectin from its Solidarity Trial for repurposed drugs for COVID-19,12 which raises questions about the pertinence of conducting clinical studies on ivermectin.

from BMJ, "Misleading clinical evidence and systematic reviews on ivermectin for COVID-19" -- https://ebm.bmj.com/content/early/2021/05/26/bmjebm-2021-111...