Do black-salve products remove skin cancer safely?

The claim, in the seller's own words

The claim is that a dark ointment applied to the skin will draw a skin cancer out, leaving a scab that falls away with the tumor inside it. No surgeon, no biopsy, no scar from a knife.

That is not a paraphrase. In April 2017 the FDA sent a warning letter to a California company selling a product called Black Salve. The letter quotes the company's own website: "The salve will work on malignancies viruses as well as other skin problems such as warts." It also quotes instructions to prick a "hard Tumor or wart" to help the salve penetrate.

The FDA's position was straightforward. Because the labeling claimed to treat disease, the products were drugs under the Federal Food, Drug, and Cosmetic Act. They were not generally recognized as safe and effective for those uses, which makes them unapproved new drugs that may not legally be sold.

What black salve actually is

Black salve has no standard formula. Reviews in the medical literature describe it as a mix of otherwise inert ingredients turned corrosive by adding bloodroot, the plant Sanguinaria canadensis, or zinc chloride, or both.

The active compound from bloodroot is sanguinarine. It is an escharotic: a substance that kills tissue on contact and leaves behind a thick dead crust called an eschar. The crust separating from the skin is the part sellers point to as proof the treatment worked.

What the evidence shows

A 2018 review in the Journal of Dermatological Treatment looked at black salve as a skin cancer treatment and found clinical trials lacking. The clinical evidence that exists is mostly case reports, and they describe poor results both medically and cosmetically. Laboratory work on sanguinarine points to indiscriminate destruction of healthy tissue alongside abnormal tissue.

A 2015 review in the Journal of Alternative and Complementary Medicine reached the same conclusion. It found no objective evidence supporting black salve as a skin cancer treatment, and it warned about cosmetic damage from tissue death caused by bloodroot and zinc chloride.

A 2022 case report describes a 55-year-old man who applied a commercial black salve ointment to a lump on his neck and left it in contact with the skin for seven days. He needed oral antibiotics, a referral to wound care, and was left with a sunken scar.

The part that does the real damage

An escharotic burns downward and outward without regard for where a tumor ends. It cannot tell tumor from healthy skin, and it cannot see how deep a tumor goes.

That creates two problems at once. Cancer left behind under a healed scar is harder to find and harder to treat later. And the scar itself destroys the information a pathologist would have used.

NCI's health-professional summary on melanoma is unusually direct on this point: suspicious lesions should never be shaved off or cauterized. A biopsy, preferably by local excision, should be done, and an experienced pathologist should examine the specimen so the tumor can be microstaged.

Microstaging is the whole game in early skin cancer. Thickness and features under the microscope determine the width of the excision, whether a lymph node is sampled, and what follow-up looks like. Burn the lesion off and none of that can be measured.

What real treatment looks like

NCI lists the options for localized basal cell carcinoma: surgical excision with margin evaluation, Mohs micrographic surgery, radiation, curettage and electrodesiccation, cryosurgery, photodynamic therapy, topical fluorouracil, topical imiquimod, and carbon dioxide laser.

For localized squamous cell carcinoma the list is surgical excision with margin evaluation, Mohs surgery, radiation, curettage and electrodesiccation, and cryosurgery.

Several of these are non-surgical, and two of them — fluorouracil and imiquimod — are creams. The difference from black salve is not that one is a cream and the other a scalpel. It is that these have been tested, are dosed, and are used after someone has established what the lesion is. Our page on basal cell and squamous cell skin cancer covers how those choices are made.

When to get checked

NCI's ABCDE list describes the features of a pigmented spot that may signal melanoma:

• Asymmetry of the lesion
• Border irregularity
• Color variation
• Diameter greater than 6 mm
• Evolution, meaning any change in the lesion

NCI adds these early signs of change in an existing mole: it darkens or becomes patchy in color, it itches, it grows or sprouts satellite spots nearby, or — later — it ulcerates or bleeds.

Any of those is a reason to see a clinician, not to reach for an ointment. Our page on when to worry about a mole explains what an examination involves.

What this does not mean

• The absence of good evidence is not proof that black salve never removes tissue. It plainly removes tissue. The question is whether it removes the right tissue, and there is no evidence it does.
• Not every skin lesion is cancer, and not every skin cancer needs surgery. That judgment requires a diagnosis first.
• Reading pathology is itself imperfect. NCI cites a panel of experienced dermatopathologists who disagreed on 37 of 140 cases. That is an argument for a second opinion, not for skipping the biopsy.
• An FDA warning letter is an enforcement action against specific claims by a specific seller. Products with different names keep appearing.
• Nothing here is advice about a lesion on your own skin. That needs someone to look at it.

Sources

• FDA, Warning Letter to Healing Within Products & Services, Inc., CMS# 513213, April 17, 2017 — https://www.fda.gov/inspections-compliance-enforcement-and-criminal-investigations/warning-letters/healing-within-products-services-inc-513213-04172017
• FDA, Products Claiming to "Cure" Cancer Are a Cruel Deception — https://www.fda.gov/consumers/consumer-updates/products-claiming-cure-cancer-are-cruel-deception
• NCI PDQ, Melanoma Treatment (Health Professional Version) — https://www.cancer.gov/types/skin/hp/melanoma-treatment-pdq
• NCI PDQ, Skin Cancer Treatment (Health Professional Version) — https://www.cancer.gov/types/skin/hp/skin-treatment-pdq
• Lim A. Black salve treatment of skin cancer: a review. J Dermatolog Treat. 2018;29 (PMID 29098921) — https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&id=29098921&retmode=xml
• Eastman KL, McFarland LV, Raugi GJ. A review of topical corrosive black salve. J Altern Complement Med. 2015;20:284-9 (PMID 24175872) — https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&id=24175872&retmode=xml
• Black salve: risky escharotic. Scars Burn Heal. 2022 (PMID 36157312) — https://eutils.ncbi.nlm.nih.gov/entrez/eutils/efetch.fcgi?db=pubmed&id=36157312&retmode=xml

How this article was prepared

An AI-assisted editorial system helped prepare this page. No named medical reviewer has reviewed it unless one is listed.

The National Cancer Information Foundation publishes Cancer Explained. This page is for learning. It is not medical advice and does not suggest a test or treatment.

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