Electrical polarity provides the driving force for transporting an ionized substance. A charged molecule is repelled by an electrode carrying the same polarity, encouraging movement away from that electrode and toward the skin. This electrorepulsion helps direct the substance through the stratum corneum rather than relying solely on passive diffusion.
The stratum corneum is the outer skin layer that the transported substance must cross before reaching underlying tissue or sweat glands. Applying a controlled low current helps move ionized molecules through this barrier. Overcoming that barrier is central to achieving localized delivery and to stimulating sweat when the technique is used diagnostically.
A controlled low electrical current regulates the driving force applied during treatment. This allows ionized substances to be transported through the skin while supporting a noninvasive approach. Current control is relevant to both therapeutic delivery and diagnostic testing because the technique must direct substances or stimulate sweat without using injections.
The process uses electrodes, an ionized substance when drug delivery is intended, and a controlled low electrical current. The electrodes are positioned to establish the required polarity, then the current drives the charged substance through the stratum corneum into underlying tissue. For diagnostic use, the setup can instead support sweat stimulation.
Medical teams may use iontophoresis to administer anti-inflammatory or anesthetic agents to a targeted area. Transport through the skin can support localized therapy while reducing reliance on injections and limiting systemic exposure. This makes the technique relevant when treatment goals focus on a particular region rather than delivery throughout the body.
Its applications extend beyond drug delivery. Iontophoresis can stimulate sweat for diagnostic testing associated with cystic fibrosis, providing sweat for evaluation. It can also be used in treating excessive sweating. These uses show how the same current-and-electrode approach can support either measurement-related sweat production or a therapeutic goal.