With endorsements from a controversial French physician, Fox News, and Donald Trump, hydroxychloroquine – an old anti-malarial drug that is today more commonly used to treat lupus – has received a disproportionate amount of attention as a potential treatment for Covid-19.
The limited evidence around hydroxychloroquine so far has come in a steady stream of scientific studies, often as soon as they are posted online as “preprints” – i.e. before they have gone through the rigorous vetting process known as peer review.
None of the studies that have been released meet the gold standard for demonstrating a drug’s effectiveness – a large-scale, double-blinded randomized controlled trial (RCT), though multiple trials of that kind are under way.