Iontophoresis is a technique that can be helpful with some chronic tendon injuries, and is sometimes prescribed by your referring provider.  “Ionto” utilizes an electrical current to push a specific chemical compound (usually a type of topical steroid – although not always) through your skin in order to target the affected tissue.  With this in mind, it tends to work best for injuries that occur close to the skin (e.g. Golfer’s elbow)