Polidocanol (Aethoxysclerol 0.5%) is a medication typically used for the treatment of varicose veins. More recently, it has also been used in the treatment of tendon problems (tendinosis), as well as surrounding tendon inflammation, known as tenosynovitis. Though not well understood, in an attempt to heal the body of the tendinosis, new blood vessels and nerves grow into a diseased tendon, producing pain. Targeting these new blood vessels with Polidocanol often results in relief of symptoms.