Record ID: MS-N077 · Family: Caustic topical product / unsupported cancer-treatment claim · Clinical question: Does black salve safely remove skin cancer?

Evidence label: No reliable evidence of safe, complete cancer treatment; corrosive injury, scarring, delayed diagnosis and persistent cancer are documented.

Evidence at a glance

• Benefit: Tissue destruction or an eschar does not prove complete cancer removal.
• Certainty: Moderate that serious local harm and treatment failure occur; no controlled efficacy evidence exists.
• Risk: Necrosis, infection, disfigurement, delayed diagnosis and progression of residual cancer.
• Cancer control: Unsupported. A lesion disappearing at the surface does not establish clear microscopic margins.

What is known

Black salves commonly combine bloodroot-derived compounds with zinc chloride or other corrosive ingredients. Products are applied to a lesion until tissue dies and forms an eschar.

A dermatopathology series reviewed 16 lesions from 11 people who self-treated with black salve. Reviews of published cases describe variable tissue destruction, residual benign or malignant lesions, scarring and delayed conventional diagnosis. There are no randomized trials demonstrating complete, margin-controlled cancer treatment.

What the results show

The visible endpoint—burning, necrosis and a scab—is nonspecific: the product can destroy healthy and diseased tissue indiscriminately. Without pathology and margin assessment, it cannot show that melanoma, basal-cell carcinoma or squamous-cell carcinoma has been fully removed.

FDA has warned that bloodroot and zinc chloride are corrosive, that black salves may cause permanent disfigurement, necrosis and infection, and that self-treatment of moles can delay diagnosis and allow cancer progression. FDA reports include at least one death after a person chose corrosive salve instead of proven therapy.

Important limits

• The human literature is dominated by case reports and case series, which can document harm but cannot estimate efficacy.
• Products and concentrations vary and may not match their labels.
• Some lesions treated by users were never biopsied, so the original diagnosis may be uncertain.
• No standardized dose, duration or follow-up protocol has been validated.

Safety and practical context

Do not apply black salve to a mole or suspected cancer. Arrange clinical examination and biopsy. If it has already been used, urgent assessment may be needed for infection, bleeding, severe pain, tissue loss or a lesion near the eye, nose, mouth or genitals; pathology may still be necessary after the surface appears healed.

Questions for the care team

• Has the lesion been examined and biopsied?
• Could melanoma or another aggressive cancer be present beneath the visible injury?
• Is there infection, uncontrolled pain or tissue damage requiring urgent care?
• What standard treatment would provide pathology and margin control?

Sources checked

• Lim, Black salve treatment of skin cancer: a review, 2018 (PMID 29098921).
• Leecy et al., 16 lesions from 11 patients and literature review, 2013 (PMID 24150196).
• FDA warning letter describing bloodroot/zinc chloride corrosive injury, October 6, 2020.
• FDA medication-health-fraud discussion, March 19, 2024.

Last literature search: October 19, 2026 · Record appraisal: October 19, 2026

Educational information only. This record is not a prescription and does not replace advice from the oncology team or oncology pharmacist.