Sodium tetradecyl sulfate (STS) is an anionic surfactant used in the sclerosant drug Sotradecol. It is commonly used in the treatment of varicose and spider veins of the leg, during the procedure of sclerotherapy. Being a detergent-based chemical, its action is on the lipid molecules in the cells of the vein wall, causing inflammatory destruction of the internal lining of the vein and thrombus formation eventually leading to sclerosis of the vein. It is used in concentrations ranging from 0.1% to 3% for this purpose. In the UK, Ireland, Italy, Australia, New Zealand and South Africa, it is sold under the trade-name Fibro-Vein in concentrations of 0.2%, 0.5%, 1.0%, and 3%.
As of 30 October 2009, it has been claimed that it can also stop snoring when injected into the roof of the mouth by hardening the soft tissues which vibrate.