While there is some evidence that chloroquine phosphate and a related compound hydroxychloroquine can be effective against COVID-19, most of the data we have is "in vitro," meaning experiments done in the test tube and not in humans.

It is too early to say definitively whether these drugs will be effective in fighting COVID-19, and thorough clinical trials are underway to determine effectiveness in people.

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 3 April 2020