Frequently, I field questions from patients about alternative therapies for treating the skin and specifically skin cancer. One of the most interesting treatments available is called “Black Salve” – interesting because it is not merely a placebo, but rather does have real effects. Black salve is also interesting because its history has intersected with that of allopathic medicine in ways that are important to medicine’s most advanced skin cancer treatments. Black salve has been used for decades as a way to treat growths including warts, moles and even skin cancer (but dermatologists do not recommend using it for this purpose).
Black salve is a mixture of zinc chloride and Sanguinaria canadensis (aka Bloodroot), and sometimes Larrea tridentata (aka creosote bush or chaparral). But what are these three ingredients?
Zinc chloride is an escharotic and tissue fixative. An eschar is a piece of dead tissue that will eventually turn black and slough off the skin. When applied to the skin, zinc chloride causes cell death and chemically fixes tissue into a relatively hard dead mass or plaque -- an “eschar.” If applied to a skin cancer, zinc chloride may kill the cancer, but the zinc chloride may also damage surrounding tissue. Zinc chloride is non-specific, damaging both unhealthy and healthy tissue that it contacts. Numerous case reports exist in the medical literature of people applying zinc chloride paste only to have a cancer come back worse or metastasize. Application of this paste has also been reported as causing severe scarring and deformity.
Bloodroot is a flowering plant indigenous to eastern North America. Bloodroot gets its name from a red sap that can be harvested from the roots to dye baskets or cloth. Bloodroot also produces an ammonium-based chemical that kills animal cells and that is an escharotic, similar to zinc chloride.
Creosote or chaparral is a desert plant whose extracts include certain compounds touted as having antioxidant properties. Chaparral is listed in the FDA’s poisonous plant database where its entry states that it has caused liver injury and even fulminant hepatic failure requiring a liver transplant.
An interesting intersection of black salve with allopathic medicine is that Dr. Frederick Mohs used a compound combining zinc chloride, antimony trisulfide and bloodroot as a “chemopaste” that was instrumental in helping him to develop “Mohs surgery” – the skin cancer treatment that bears his name and is now the most effective, precise and advanced method for treating skin cancer. Developed in the 1930s, Mohs’ chemopaste allowed him to harden and fix a skin cancer and a small area of surrounding skin. He then would remove that area, slice it thinly and examine it under the microscope to make sure that the margins were clear of tumor. When cancer was still present at an edge, he would remove more skin from the patient and again examine it under the microscope until all the cancer had been removed. The chemopaste was often applied the night before surgery, was very painful and caused substantial damage to surrounding tissue. Mohs’ method of using chemopaste and examining tissue under the microscope was imperfect, but it was certainly better than alternative methods of skin cancer removal available at the time.
By the late 1970s, machines that could freeze tissue and allow it to be cut with precision and without the use of this chemopaste became available, making the chemopaste obsolete. Modern Mohs surgery involves numbing a skin cancer and the surrounding skin with lidocaine, removing the visible tumor and a small margin, checking the edges for tumor and repeating this process until all microscopically visible cancer has been removed. Modern Mohs surgery results in a 99% cure rate for most skin cancers, and suturing and repair techniques are so refined that deformity is extremely rare and in most cases minimal scarring occurs.
Black salve’s cousin “Mohs’ chemopaste” played an important role in the development of Mohs surgery. Patients inclined toward naturopathic remedies should not feel that choosing Mohs surgery over black salve is a rejection of their holistic worldview. Rather, modern medicine and evidence-guided physicians honor the natural world when we acknowledge the astounding number of modern treatments derived from nature and guide our patients toward therapies that offer the greatest chance to heal. Black salve should not be viewed as an alternative to Mohs surgery but rather as an important historical stepping stone to this incredibly effective surgical technique.
If you or a loved one has skin cancer, consider Premier Dermatology and Mohs Surgery of Atlanta. Dr. Brent Taylor is a board certified dermatologist, vein specialist, and fellowship-trained Mohs surgeon. He and his outstanding team take pride in providing personalized, caring and state-of-the-art treatment.