None of the well-controlled, randomized clinical studies on the impact of hydroxychloroquine on people with COVID-19 have revealed any benefit of the drug. Chloroquine and hydroxychloroquine are not to be used for the treatment of people with COVID-19 (except for certain people enrolled in clinical trials).

The experiments suggesting that chloroquine phosphate and a related compound hydroxychloroquine might be effective against COVID-19 were mostly done "in vitro," meaning experiments done in the test tube and not in humans.

It is important to note that chloroquine phosphate and hydroxychloroquine can be toxic, and should not be used unless prescribed by a doctor. There have been several reports of individuals trying to self-medicate and dying from "chloroquine poisoning."

Drafted 12 October 2020