Sodium lauryl sulfate (SLS), sodium laurilsulfate or sodium dodecyl sulfate (SDS or NaDS) is an anionic surfactant used in many cleaning and hygiene products. The molecule has a tail of 12 carbon atoms, attached to a sulfate group, giving the molecule the amphiphilic properties required of a detergent.

SLS is a highly effective surfactant and is used in any task requiring the removal of oily stains and residues. As such the compound is found in high concentrations in industrial products including engine degreasers, floor cleaners, and car wash soaps. In household products, SLS is used in lower concentrations with toothpastes, shampoos, and shaving foams. It is an important component in bubble bath formulations for its thickening effect and its ability to create a lather.

Research suggests that SLS could represent a potentially effective topical microbicide, which can also inhibit and possibly prevent infection by various enveloped and non-enveloped viruses such as the Herpes simplex viruses, HIV, and the Semliki Forest Virus

It has recently found application as a surfactant in gas hydrate or methane hydrate formation reactions, increasing the rate of formation as much as 700 times.

In medicine, sodium laurilsulfate is used rectally as a laxative in enemas, and as an excipient on some dissolvable aspirins and other fiber therapy caplets.

Sodium lauryl sulfate is increasingly found in all kinds of common over the counter orally ingested drugs like aspirin as well as prescription medicines like drugs for heart problems. The reason for this is that it aids the production process by helping tablets not to stick to the mould when pressed into shape. The long term health implications of this for patients has not been the subject of any studies, and in the UK for instance it is now virtually impossible to get aspirin of any brand, standard or dispersible that does not contain sodium lauryl sulfate.