Iontophoresis is a method of delivering medication through the skin by way of a gentle electrical current rather than by injection. The drug is pressed onto the affected area through an electrode pad, which enables direct current to drive it into the skin through sweat ducts, sebaceous glands, hair follicles and dermal imperfections. Iontophoresis is most commonly used for patients suffering from plantar fasciitis, Achilles tendonitis, shoulder tendonitis, elbow tendonitis (cures for tennis elbow) and bursitis of the hip and shoulder. This tendonitis treatment is not recommended for everyone, however, and must be prescribed by a physician.