Fibro-Vein is a detergent based sclerosant and is licensed for the treatment of varicose veins. It is a sterile aqueous injection of Sodium Tetradecyl Sulphate (STS), an anionic detergent, and has been used in the treatment of varicose veins since 1946. Fibro-vein is manufactured in the UK and is the only STS based sclerosing solution that complies with British Pharmacopoeia specifications.