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Quick Facts

  • Method of Action:


  • Efficacy Range:


  • Pain During Treatment:


  • Recurrence Rate:


  • Pain Post Treatment:


  • Patient Satisfaction:

    Low to moderate

  • Number of Treatments Required:


More About Cathandarin

Cantharidin comes from an insect known as the blister beetle, Cantharisvesicatoria. It causes epidermal cell death and removes the wart through the formation of a large blister. Since 1992, the FDA no longer permits it’s sale in the United States but it can be purchased in Canada.

  • How does this treatment work?

    Cantharidin works by interacting with the mitochondria of the skin cells causing death and resulting in a large blister. The blister encompasses the wart and as the blister heals, the wart is destroyed in the process. The HPV virus is not affected by Cantharidin.

  • How effective is this treatment?

    While there are no randomized control trials that currently exist for cathandarin, anecdotal evidence suggests clearance rates higher than that of cryotherapy or salicylic acid. The challenge is (a) availability (not FDA approved in the US and only available from Canada) and (b) pain levels post treatment. As a result, this treatment is not nearly as commonly used as the others listed, but can be considered for second line therapy to simply remove the wart should treatment prove ineffective.

  • What can patients expect when receiving this treatment?

    Typical Treatment Protocol:

    • Wart is typically pared back prior to application
    • Cathandarin is applied directly to the wart
    • Must be kept occluded for 4-8 hours then washed off


    • Limited pain during the procure as the cathandarin is applied, however once the blister forms, the pain can be significant, especially when on the foot.

    Post Procedural:

    • Within 24 hours a painful blister will begin to form
    • You must not de-roof the blister (do not agitate)
    • Treatment typically repeated in 1-3 weeks


    • Limited risk of scarring
    • Annular ring may occur around the treated wart
    • Recurrence
  • Where can I receive this treatment?

    As Cathandarin is not approved by the FDA, it can be more challenging to acquire. For this reason, you are best to call ahead to a podiatry or dermatology clinic if you wish to be treated with Cathandarin as most clinics will not have access.