This is a supposed cure for skin cancer – a paste made from a perennial flowering plant which grows in northeastern America. The common names for this plant are blood root, Indian paint, and red root, as well as black salve. It contains zinc chloride and a sanguinarine, a compound which, if applied to the skin, destroys cells and produces a scar of dead tissue. It was used by Native Americans as a medicinal agent and this has given credence to its use today. Those who support its use claim that it kills the cancer cells and leaves the good cells alone. In the strengths in which it is supplied, this is not true.
There is a possibility that the sanguinarine may have a role to play in suppressing cancerous cells but the research has not been done. Black salve was banned in Australia in 2012 but it is still possible to obtain it online. There are always those who are hoping for the quick fix.