The US Food and Drug Administration has issued a warning.
In October of 2020, due to increasing reports of harmful outcomes from the use of black salve, the FDA issued a warning against the use of any products containing bloodroot, alone or in combination with zinc chloride. The FDA warning states:
Salve products containing corrosive ingredients, including black salve, are dangerous and are not approved by the U.S. Food and Drug Administration (FDA) to treat or cure any skin condition, particularly not skin cancer. Specifically, the FDA is warning consumers not to use any salves or other topically applied products that list any of the following potentially dangerous ingredients: sanguinarine, Sanguinaria canadensis, or bloodroot, alone or in combination with zinc chloride.
Although not all salves are dangerous, topically applied products with the above ingredients can destroy the skin and result in permanent disfigurement, tissue necrosis (death of cells in living tissue), and can result in infection. Furthermore, using salve products such as black salve for serious conditions like skin cancer can result in delayed cancer diagnosis and cancer progression.
The FDA has identified 24 cases of adverse events (bad side effects) associated with black salve. Fifteen of these cases were reported within the past five years.
These have included instances of permanent disfigurement and cancer progression. The FDA is aware of at least one death that resulted from a person who opted to use a corrosive salve rather than pursue proven cancer therapies. The agency urges consumers to see a health care professional to obtain an accurate diagnosis and receive appropriate treatments. The agency also continues to send warning letters and take enforcement action against companies making false claims about these products.