Tetradecyl hydrogen sulfate (ester)
Sodium tetradecyl sulfate is an anionic surface-active agent which is used for its wetting properties in the industry and is also used in medicine as a blood vessel irritant and sclerosing agent for hemorrhoids and varicose veins.  Sodium tetradecyl sulfate has been widely used since the 1950s, and in 1978 the first successful report of injecting a 1% solution into spider angiomas in 144 patients was made. Also noted was an unspecified number of episodes of epidermal necrosis without significant long-term effects and a 30% incidence of post-sclerosis pigmentation that resolved within a few months.