Black salve

Black salve, also known by the brand name Cansema, is an ineffective and unsafe alternative cancer treatment. The product is commonly classified as an escharotic—a topical paste which destroys skin tissue and leaves behind a scar called an eschar. Escharotics were widely used to treat skin lesions in the early 1900s, but have since been replaced by safer and more effective treatments. Escharotics, such as black salves, are currently advertised by some alternative medicine marketers as treatments for skin cancer, often with unsubstantiated testimonials and unsupported claims of effectiveness.

The U.S. Food and Drug Administration has listed Cansema as a "fake cancer cure" and warns consumers to avoid it.