It uses liquefied nitrous oxide to destroy the tissue by freezing the cell fluid which in turn forms ice shards that rupture the cell membrane and destroy the cell and lesion.
The penetration rate of freezing with the cryopen is around 1 to 30 seconds. The duration of the treatment time will depend on the surface area and thickness of the tissue being treated.
For most lesions, cryosurgery is a permanent removal. Some lesions are harder to remove than others. In more delicate places eg the eye area, a shorter freeze time with a repeat procedure may be required to get a final result with the least damage to the surrounding skin. In other instances a deep lesion eg a verruca or a wart may take several aggressive treatments to get final results.