Black salve, also known by the brand name Cansema, is a dangerous and controversial alternative cancer treatment. The product is commonly classified as an escharotic—that is, a topical paste which burns and destroys skin tissue and leaves behind a thick, black scar called an eschar.[1] Escharotics were widely used to treat skin lesions in the early 1900s, but have since been replaced by safer and more effective treatments.[2] Escharotics, such as black salves, are currently advertised by some alternative medicine marketers as treatments for skin cancer, often with unsubstantiated testimonials and unproven claims of effectiveness.[3]