A study done in 2020 that was widely used by the Covid lunatic fringe crowd has finally been retracted by the authors who concede there are huge problems with the study.
First off, it only had 36 people. Second it was published 4 days after being submitted for "peer review" which is way faster than normal. A subsequent look at the study revealed 6 of the patients dropped out of the study, 1 died, 3 were in intensive care 2 more seriously ill, all 6 had.... Covid.
The study was the starting point of the entire HCQ for Covid movement.
The co author at one point had co authored 32 scientific papers, 28 of which have now been retracted for being inaccurate if not outright fraud.