How Hydrozid Works

  • Cryotherapy works because different types of skin cell have different damage thresholds at low temperatures
  • The upper cell layer of the skin, the epidermis, made up of 95% keratinocytes is much more sensitive to temperature changes than the underlying dermis, which consists of a large network of collagen fibres and fibroblasts
  • The pigment-producing melanocytes in the epidermis is also extremely sensitive to temperature change
  • Cryotherapy is practicable, as it is in the epidermis that a number skin diseases manifest themselves, for example, warts and various form of sun damage
  • Cryotherapy can thus target diseases in the upper tissue layers without damaging the underlying tissue


  • Hydrozid is applied to a lesion directly from the canister
  • Hydrozid should be applied from a distance of 2 to 3 cm and for 2 to 6 seconds, depending on the location of the lesion
  • Several repeated freeze-thaw cycles – up to 6 with 30 seconds intervals – are recommended as a single treatment
  • The total duration of application to a lesion must be kept within the recommended maximum total (see below)
  • Gently press the spray head to give a fine, narrow jet. Press more firmly for a more powerful jet
  • Some conditions may need repeated treatment to successfully remove a skin lesion. When repeat treatment is needed intervals of 1 to 2 weeks between treatments are recommended
  • Caution!
    • Cryotherapy may produce a stinging or burning sensation on the skin
    • Necrosis of epidermal cells may result in the development of a blister
    • Full recovery takes about 10 to 14 days
    • Overexposure may lead to hypopigmentation, scarring or post- inflammatory hyperpigmentation

Recommended treatments

Application templates


  • To avoid damaging surrounding tissues you may use one of the application templates provided
  • Carefully select the hole in the template which matches the size of the lesion and adjust the spray jet by varying the pressure on the spray nozzle
  • Using application templates, you can treat almost all sizes of skin lesion without causing damage to the surrounding healthy tissues
  • Each template has six holes of different diameters; 3, 4, 5, 6, 8 and 10mm, respectively
  • The Hydrozid application templates are for single use and can be discarded as household waste after use
  • Due to the risk of infection, each application template should be used for one skin lesion only
  • The application template should be used only during treatment with Hydrozid