At long last, the first randomized trial of the malaria drug hydroxychloroquine (HCQ) has issued results in a peer-reviewed paper. This experiment treated people who had been exposed to SARS-CoV-2 within the last four days but hadn’t yet shown symptoms. In short, it made no difference whether people got the drug or a placebo.

[6/04/20 Update: The observation study I referenced in the next was retracted today. The conclusion I came to – that people should not take HCQ outside of clinical trials – remains the same.]
These results build on last month’s observational study that found that patients who were hospitalized with COVID-19 also received no benefit. At the time, I’d said people shouldn’t take HCQ to treat or prevent COVID-19 outside of a clinical trial. This new paper definitely backs up that advice. There’s still some possibility that randomized trials already underway could find a benefit for patients showing symptoms, but it seems like a long shot.