In the US, a drug called Ivermectin is being touted as a way of treating or preventing for Covid-19, with celebrities such as podcast host Joe Rogan praising its use.
That's despite official advice which says it's not approved for this purpose.
Ivermectin is primarily used for parasitic infections in animals and also has some application for humans in small doses.
Ros Atkins explores why people continue to use the controversial drug.
Producer: Briony Sowden
